sa roofing april 2016 | issue: 78
DESCRIPTION
SA Roofing is the only publication in South Africa that is dedicated exclusively to the residential, commercial and industrial roofing and re-roofing industries.TRANSCRIPT
APRIL 2016 ISSUE: 78WWW.TRADEMAX.CO.ZA SA R36 EACH INCL. / R360 PER ANNUM INCL.
APRIL 2016 ISSUE: 78
EDITOR’S COMMENTS ..................................................................................................... 2
CONTRIBUTORS & EVENTS .......................................................................................... 4
TIMBER TRUSSES ............................................................................................................ 6-8
COVER STORY..............................................................................................................11-12
ROOF STRUCTURE FAILURES ............................................................................... 14-17
STRUCTURAL ROOF REPAIRS .............................................................................18- 20
CEILING INSULATION ............................................................................................. 22-23
CLAY ROOF TILES ............................................................................................................ 25
CONCEALED FIX PROFILE ........................................................................................... 27
THATCH ........................................................................................................................28-29
THATCH MAINTENANCE ......................................................................................30-31
THATCH ........................................................................................................................ 32-39
SAISC NEWS ...................................................................................................................... 40
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Trademax Publications
SA Roofing Tel: 0861 SA ROOF (0861 727 663) Fax: 0866 991 346Email: [email protected]
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PUBLISHER: Billy Perrin 082 266 6976 [email protected]
EDITOR: Celéste Perrin [email protected]
ADVERTISING: Jacqui Marsh [email protected]
LAYOUT & DESIGN: Craig Patterson [email protected]
SUBSCRIPTIONS: Belinda Thwesha [email protected]
INTERN: Micaela Tatar [email protected]
DISCLAIMER The views expressed herein are not necessarily those of Trademax Publications. Although we have done our best to ensure the accuracy of our content, neither Trademax Publications nor SA Roofing magazine will be held liable for any views expressed or information disseminated, in editorial content or advertisements, in this issue.
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I was very impressed when I read about the launch of the Solar Capital De Aar 3, the 17th solar photovoltaic plant in the Northern Cape and a project that is expected to contribute
164GWh to the grid annually – enough power to supply about 49,500 typical South African households with electricity each year. In my book, that’s remarkable. The Northern Cape region has become a Mecca for the development of renewable energy sources and boasts the majority of ‘sun cities’ in our country, with these PV plants quietly playing their part in the drive to be more and more energy efficient. The Northern Cape has proven itself to offer some of the best conditions in the world for solar electricity generation. Few other countries can top that.
In truth, South Africa holds so much experience, skill, talent and knowledge across the board – from sports to medicine to industry – that there are many fields in which we are recognized as the best. As only one example within the roofing industry – we can proudly lay claim to the best thatchers in the world, as you will see in this issue of SA Roofing. Is it therefore unreasonable to expect such excellence to be a consistent, standard benchmark across all roofing sectors?
Also in this edition, we feature a couple of articles that tackle the problem of roof failures head-on, from a roof inspector’s perspective. I’m sure the viewpoints are going to elicit responses (perhaps mixed?) and open up additional dialogue, which will be ideal to put further emphasis on not only the problem, but the solution. The fact remains – roof failures due to faulty or poor workmanship are unacceptable, especially when lives are put at risk. As a profession, surely we can do better? It is definitely a serious topic and one that SA Roofing is happy to address, so feel free to join in the discussion and send us your comments.
On a more positive note, there is still a whole lot our roofing industry can and should be proud of. I hope you enjoy the top-notch projects showcased this month, not to mention the exciting product launches and news in the pages to follow – all proving that we are ‘better than that.’
Until next time, let’s keep at it.Celéste
Better than thatSometimes we have to ask ourselves: Can’t we do better than that?
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WHEN IT COMES TO ROOF STRUCTURES, OVERLOOKING THE SMALL DETAILS CAN SOMETIMES LEAD TO DEVASTATING CONSEQUENCES.
Photographs courtesy of Tinus de Jager.
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In 2004, as part of the practical training required to complete his National Diploma in Mechanical Engineering, Stian de Jager completed the Roof Inspector's Course through Roof Inspection Services (under the tutorship of the late Victor Booth, a Specialist Engineer in Timber Engineering). After his certification, he registered with the ITC-SA as a Qualified Roof Inspector. Whilst completing his Bachelor's Degree in Mechanical Engineering, de Jager actively worked as a roof inspector and formed De Jager Roofs Business Trust in 2007. A partnership with his grandfather Chris de Jager, who came from a municipal building inspector background to become one of the very first roof inspectors, allowed him to further expand on his roof consultancy experience.
In 2011, Stian was appointed General Manager for Tlhomeso Timbers and Vertex Roofing Contractors, the largest roof truss manufacturers in Botswana. There, while working closely with professional engineers in the timber roof truss industry on, amongst other projects, roof failures and remedials, he furthered his qualifications to include a 20/20 Advanced Designer Certificate from MiTek. In addition, he was mentored by Cor van Os, a pioneer in the roofing industry, often leading system providers in new concepts and management software solutions. In 2012, he was sent to the USA to oversee the rigging and importing of various types of advanced roof truss manufacturing equipment, including the first TCT automated linear saw. His experience eventually led de Jager to consult for MiTek and other South African truss plants on calibration, fault finding and training related to these saws.
De Jager returned to South Africa in 2015 to continue his inspection and consulting work in De Jager Roofs Business Trust. He remains committed to add value and make a significant contribution to the industry through his knowledge, experience and skills.
Tinus de Jager completed his roof inspector’s training in 2000 through Roof Inspection Services, which was headed up by the late Victor Booth, a Specialist Engineer in Timber Engineering. Under Mr Booth’s mentorship, de Jager gained expert knowledge and experience in conducting both domestic and commercial roof structure inspections. De Jager became an accredited ITC-SA member (the Institute for Timber Construction SA) in 2001 and has served on the ITC-SA Board of Directors as Inspector Director. Other duties for the ITC-SA have included qualifying audits on licensed truss fabricators prior to issuing such fabricators with a ‘Certificate of Competence.’ In 2005, de Jager successfully completed the ITC-SA Basic Estimator Designer course. He also founded Dynamic Roofs, a truss manufacturing plant offering design, manufacturing
and erection services for new roof structures, which he oversaw from 2009 to 2011. With a wealth of experience under his belt, de Jager regularly does roof structure assessments for private home owners, insurance companies, banks and engineering firms.
Liesl Schoonraad developed a love for thatch at a very young age. She was only five years old when she told her father that she was going to one day use thatch to “make ugly houses pretty.” In 1994, after obtaining her architectural qualification, she did exactly that when she started working for Jason Lucas, South Africa’s only qualified master thatcher. Liesl is today still working for Jason Lucas Master Thatchers, dedicating her time to work on thatch conversions and renovations specifically. Liesl applied her extensive experience and expert thatch knowledge while assisting in the compilation of ‘A Guide to Thatch Construction in South Africa’ for the Thatchers Association of South Africa (TASA), due to be launched in April 2016.
STIAN DE JAGER
TINUS DE JAGER
LIESL SCHOONRAAD
Upcoming EventsTHATCHERS ASSOCIATION OF SA (TASA) 10TH ANNIVERSARY + LAUNCH OF TASA’S “GUIDE TO THATCH CONSTRUCTION IN SOUTH AFRICA”23 APRIL 2016 | FOREVER HOTEL, CENTURIONEmail [email protected] for more info or visit www.sa-thatchers.co.za
HOUSING FOR AFRICA CONFERENCE & TOTALLY CONCRETE EXPO9 - 11 MAY 2016 | GALLAGHER CONVENTION CENTRE, MIDRAND, JHBVisit www.totallyconcrete.co.za and www.construction-week.com for more info
A-OSH EXPO SOUTH AFRICA 201624 – 26 MAY 2016 | GALLAGHER CONVENTION CENTRE, MIDRAND, JHBVisit www.aosh.co.za for more info
WOODEX FOR AFRICA9 – 11 JUNE 2016 | GALLAGHER CONVENTION CENTRE, MIDRAND, JHBVisit www.woodexforafrica.com for more info
CAPE CONSTRUCTION CONFERENCE & TRADE EXPO11 – 12 AUGUST 2016 | CTICC, CAPE TOWNVisit www.cape-construction.co.za for more info
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When Rooftek was given the brief, it consisted of a photo taken in the USA and a basic design. In line with Bruwer’s general mandate to “Keep it straight
and simple,” Rooftek responded promptly with a 3D design for approval, followed by a prepared budget that addressed the scope of the work. Ultimately, Bruwer says, the project was awarded on a design, supply and fit basis.
FAST FACTSAlthough the footprint was not that big, Bruwer says, there are some noteworthy facts to consider:
AVERAGE TRUSS WEIGHT: ±500kgHEAVIEST TRUSS: 1,600kgLARGEST TRUSS: 14.5m x ±3.5mHIGHEST DESIGN LOAD: 60kNWIND LOAD CATEGORY: 1/ASTEEL COVER PLATE AND RODS: ±6.5 tonsVOLUME OF LUMBER USED: 28m³M16 CUP-HEAD BOLTS AND NUTS: 3,500
DESIGN DETAILS Rooftek partnered with MiTek Industries in the design process.
The design was done as a ‘Space Frame,’ meaning that the design criteria took all the dimensional elements, in all directions, into consideration. As a result, the design allows for all loads to be equally distributed around the centre, where all the steel connections play a critical role.
As Bruwer notes, the outcome is a roof where the most beautiful part is indeed also the most functional part of the roof.
During the project, the Rooftek team faced several challenges, including unfactored loads of 40kN that had to be overcome. “In the worst case, the bottom cord had a tension of 60kN, meaning that the top cord had a compression of 60kN,” Bruwer states. “The purlins were spaced at only 850ctc to cater for Category 1/A wind loads, fixed with special screws (concealed) with a design value.”
Challenging brief. Straightforward solution. Rooftek Trusses in Strand, Western Cape, was approached by the project
architect to assist with the entrance to the new Vergelegen Shopping Centre in Somerset West. In this article, Kalahari Bruwer, co-owner of Rooftek, shares some of the details that made the successful completion of this
challenging project so rewarding for his team.
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TIMBER AND STEEL DETAILSpecial care was taken to select only the highest quality timber, Bruwer affirms. “All the timber, 28m³ used, was specially sourced from one sawmill. The bulk of the material was 76 x 228 South African Pine, Grade 7, clear treated timber,” he states.
Roughly 6.5 tons of steel was used. “All components were designed in CAD; laser-cut and epoxy coated,” Bruwer says.
PROBLEM SOLVING The Rooftek team had to come up with creative solutions to some of the problems associated with the project, and had to maintain the utmost standards of professionalism and workmanship to meet the demands of the brief, as Bruwer explains.
It was no easy task to source only top-quality lumber in this size and volume. It also required considerable expertise to handle trusses measuring 14.5m in length and weighing in at 1,600kg – not to mention having to safely transport such hefty loads on a public road.
Possibly the most important expectation was for the team to successfully erect the trusses and complete the project without the trusses suffering any damage.
The outcome of the team’s accomplishment is a reflection of the Rooftek motto, ‘Trust us with the roof over your head,’ as Bruwer reminds us. “We at Rooftek always strive to do something new, with all the passion and enthusiasm, in an industry that is very similar in general,” he concludes.
For more information, visit www.rooftek.co.za.
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www.bsisteel.com
PRODUCT DESCRIPTIONStarfibre™ consists of flexible rolls of insulation manufactured from recycled plastic bottles to produce a high quality polyester fibre ceiling insulation which is light- weight, strong, resilient, safe and highly thermally efficient. Starfibre™ is supplied as a plain blanket for thermal and acoustic applications in roofs, walls and ceilings in all types of buildings.
Thickness Length Width Density kg/m³Thermal
conductivityk-value (W/m.K)
Thermal Resistance
R-value (m²/KW)40mm 1200mm 10m 10 0.050 0.8050mm 1200mm 10m 10 0.050 1.0055mm 1200mm 10m 6 0.050 0.9075mm 1200mm 8m 10 0.050 1.50100mm 1200mm 6m 10 0.050 2.00135mm 1200mm 5m 10 0.050 2.70
FIRE PERFORMANCEStarfibre™ ceiling insulation has been tested according to SANS 428 (Fire Performance classification of thermal insulated building envelope systems) as part of SANS 10400 of the National Building Regulations and attained the following fire rating: B/B2/2
INSTALLATION APPLICATION1. No protective clothing required.2. Measure the distance between roof trusses.3. Cut the material to the measurements to fit between roof trusses.4. Roll the blanket out between roof trusses and ensure it lies flat on the ceiling.5. Take care to ensure that there are no gaps and the blanket is not compressed.6. Cut holes around downlighters to allow heat to dissipate.
SPECIFICATIONS FOR BOQ40, 50, 75, 100 or 135mm thick Starfibre™ceiling insulation of 10kg/m³ or 55mm thick Starfibre™ceiling insulation of 6kg/m³ density in 1200mm widths laid directly over the ceiling between trusses ensuring a snug fit including all necessary cutting strictly according to the manufacturers specifications. D&D Roof Insulations. www.roofinsulation.co.za.Handling and storage: Store under cover and in dry conditions. Handle with reasonable care and do not apply excessive pressure by standing or sitting on the product as permanent damage may occur. Store off the ground or away from impervious surfaces or moisture. The product is supplied in a compressed state and a period of 30 days should be allowed for normal thickness to be achieved.
Disclaimer:D&D Roof Insulations provides all information contained in this publication based on data available at the time and reserves the right to amend such information from time to time.
Member of TIPSASA-Thermal Insulation Products & System Association SA
Member of GBCSA -Green Building Council of SA
Head Office:Tel: 012-800 3606 • Fax: 012-800 3835 • E-mail: [email protected]
Since its establishment in 1999, Pretoria-based D&D Roof Insulations has grown to become a trusted industry leader. Committed to stay current with market trends,
changes and resulting divergent challenges, D&D Roof Insulations is well positioned to realize opportunities and deliver products that meet their clients’ specific needs as well as benefiting the final user. The company’s newest product offering, Starfibre™, is no exception.
STARFIBRE™ INSULATION Available in convenient, flexible rolls, Starfibre™ polyester ceiling insulation is made from recycled plastic bottles to provide a high-quality polyester fibre option that is light yet strong and resilient, safe, and very thermally efficient.
• Ideal for thermal and acoustic applications (supplied as a plain blanket)
• Suitable for use in roofs, ceilings and walls • Effective in commercial, industrial and residential buildings
• Fire rating of B/B2/2 achieved (tested according to SANS428 as part of SANS10400)
• Very cost-effective
EASY, SAFE INSTALLATION No protective clothing is needed when installing Starfibre™ insulation and the process is very easy. For example, in roof installations: Simply measure the distance between the roof trusses, accurately cut* the material for a custom fit, roll the blanket out between the trusses so that it lies flat on the ceiling (no gaps or compression), and cut required holes around the downlighters to allow for heat dissipation.
Starfibre™ is available in various thicknesses, at a width of 1,200mm. When laid directly over the ceiling, between trusses, you are assured of a snug fit.
*Note: Any cutting must be done in strict accordance with the manufacturer’s specifications.
Introducing Starfibre™ from
D&D Roof Insulations D&D Roof Insulations has delivered again. The renowned thermal insulation
specialist and supplier of a wide range of roof insulation materials for all industrial, commercial, retail and residential building structures brings to
market Starfibre™, the newest addition to the D&D product range.
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THE D&D PARTNERSHIP PROMISEBacked by its impressive, accumulated years of experience, D&D Roof Insulations has proven itself to be a reliable partner that can provide clients with essential guidance on construction projects – from planning stage to final completion.
Construction professionals can be assured of receiving relevant and appropriate thermal design and ventilation information as it pertains to their specific projects. The result is a satisfied developer, contractor, roofing sub-contractor and entire construction team – all completely confident that the best roof insulation has been applied in meeting the demands of that particular project.
And the D&D team’s expertise does not stop there. They can also recommend suitable and complementary accessories across the insulation product range. When it comes to aesthetics, D&D Roof Insulations knows just how important clients can rate the attractiveness of the insulation installation as part of the overall construction project. As such, the team will apply their knowledge and insight to assist clients in selecting thermally-efficient roof insulation materials that also hold the required visual appeal.
Providing details of approved roofing contractors is another way that D&D Roof Insulations upholds professionalism and delivers on its commitment to constantly raise the bar when it comes to client service. Appointing proven, trustworthy roofing contractors ensures that installations are carried out correctly from the outset, which in turn ensures all-round satisfaction with the work done.
INDUSTRY AFFILIATIONSD&D Roof Insulations is recognized throughout the industry as a thermal insulation specialist and proud to be a member of the Green Building Council of South Africa (GBCSA).
Moreover, D&D Roof Insulations is particularly proud of its founding affiliation with the Thermal Insulation Products and Systems Association of South Africa (TIPSASA), which specifically focuses on the thermal insulation industry as it relates to energy-efficient systems and products. TIPSASA’s vision, underpinned by energy-focused innovation, is well aligned with D&D Roofing Insulations’ aim to achieve product evolution that better suits its clients’ markets.
Over and above the D&D in-house products such as Starlite®, Starfibre™, Alucushion® and Insultrak™, D&D Roof Insulations is also proud to be associated with the following industry-leading brands and products: Lambdaboard™, Factoryboard, ThermocousTex™, Gypsum, Isoboard, Isolite, Factorylite, Masterliner, Energylite, Aerolite, Soundlite, Comfilite, Ductwrap, Sonic Liner, Ductboard, Cavitybatt, Sisalation® and Spunsulation.
FOR MORE INFORMATION, CONTACT:
D&D Roof Insulations(t) 012 800 3606(e) [email protected](w) www.roofinsulation.co.za
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D&D ROOF INSULATIONS – LEADERS IN THERMAL EFFICIENCY
• More than 16 years’ experience and technical expertise
• Very broad offering, products used nationally and into Africa
• Trusted to deliver custom solutions for custom requirements
• Superior service• Competitive pricing• Member of the GBCSA• Member of TIPSASA
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Many insightful and relevant articles have been published over the past few years about the roof truss industry and the role of the Institute for Timber Construction
SA (ITC-SA) with its affiliated members. For the most part, a lot of emphasis has been placed on the engineering systems, the quality control of the engineered product (trusses), and the rules that apply to the erection process of structures as determined by the relevant SANS codes and practices.
The importance of these aspects ought to be published more frequently, and be posted on every available social media outlet by the experts in the industry. Moreover, homeowners need to be educated and made aware of their responsibilities in appointing recognized professionals to oversee the construction processes of their newly erected structures.
IT’S IN THE DETAIL The focus of this article is specifically aimed at the ‘finer detail’ as contained in available Roof Erecting Standards and Procedures Manuals.
This industry is fortunate to have many highly qualified, knowledgeable and experienced people as participating stakeholders. The timber engineering industry is probably as well equipped, structured and organized as any other industry. And that begs the question: Why are catastrophic roof structure failures, in this day and age, still prevalent?
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structure failures – why are they allowed to happen?
The success of a safe roof structure lies in the finer detail, affirms Tinus de Jager as he reflects on the causes of roof structure failures, ways to combat such disasters, and the necessary interaction between roof erector and roof
inspector – from an inspector’s perspective.
Article by: Tinus de Jager, Certified Inspector (SAQA); ITC-COC/0125/INS
Catastrophic consequences of poor roof erecting practices.
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It is quite disturbing, but these incidents do not often make news headlines, if at all. The lack of news coverage subsequently leaves us in a space of complacency, creating a false reality, because we are not being made aware of the extent of the problem and we believe that all is fine in the industry. The sad and troubling reality is that all is not fine in the industry. And it is not because structures are inadequately engineered or manufactured, but because they are poorly erected and poorly inspected!
POORLY ERECTED AND POORLY INSPECTEDWe have state-of-the-art tools available to design and manufacture very complex roof structures – which should also be safe. My experience in conducting roof inspections on timber roof structures over the past 16 years has, time and again, confirmed my conclusion: Most failures are a direct result of poor, or in some cases, no assessments of these structures prior to their occupation.
The ‘fate’ or ‘serviceability’ of a structure is determined largely by a thorough assessment of the structure by a competent person, prior to the application of loads to the structure.
Inspections are being done in various ways, and it is especially worrying that in some cases they are done ‘remotely.’ This practice is not only unethical, but dangerous and criminal.
The ultimate responsibility, which should lie with the Competent Person/Engineer who performs the final assessment, is sometimes, somehow, just brushed aside to make space for what I call ‘excusitis.’ Consciousness and mindfulness seem to be scarce commodities amongst some inspectors.
The logical next question is, how then, should assessments be conducted?
PROPER ASSESSMENTSInspectors are trained to have the required design documentation at hand during an inspection. This is vital in checking that the appropriate, design-specific requirements are being met.
Together with the design output, the inspector should have extensive knowledge of the well published ‘Roof Erecting Procedures’ as contained in the SANS10243 and the SANS10400 (L) Codes of Practice, as well as the ITC-SA Roof Erecting Handbooks.
In a recent publication of the SA Roofing magazine, an expert explained (amongst other very important topics) the importance of bracing in a roof structure. The point was made that the importance of bracing cannot be over-emphasized, but that this emphasis should go one step further…
BRACING, BRACING, BRACINGIn light of recent catastrophic timber structure failures, I am prompted to expand a little on this very relevant and critical topic.
It is in the implementation/application of the bracing detail where problems are created – and the only person that can practically identify these inadequacies is the roof inspector. My view is that: “Bracing is only as effective as its connection (nailing) to the primary roof structure.”
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A common phenomenon – broken bottom cords.
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A quick glance during the assessment of a completed structure might, more often than not, create a false sense of compliance, namely that all bracing members are visibly present in their designated positions, and therefore the structure appears to be adequately braced. But a closer inspection (as further illustrated in the photographs shown) might reveal that these members are either inadequately fixed or not fixed at all. And these connections, whether they are screws or nails, are critical in ensuring an effective bracing system.
If one considers that structures are mostly designed optimally, for structural as well as economical reasons, there is absolutely no margin for error or added negligence during the erecting phase.
Every misplaced or incorrectly fixed nail or screw will compromise the strength of a joint or connection and can have far-reaching consequences.
NAILING IT The correct ‘method of nailing’ is quite clear in SANS10243 p.16. For example:
The general perception amongst roof erectors is that battens are fitted only as a means of securing roof tiles, but their purpose goes much further than that.
1. They are actually critical in ensuring the reduction of the effective length of the rafter members, against buckling, especially where multiple-ply girders are involved.
2. They are vital in transferring the effect of the top cord bracing systems to the rest of the roof structure.
Numerous cases, as I have witnessed, have proven that this inadequacy in combination with other non-compliances, can create the perfect mixture for a catastrophic failure.
WHEN SHOULD INSPECTIONS BE CONDUCTED?
• It is generally accepted that inspections on new structures should be done prior to the permanent loads (roof covering) being applied. Unbraced or partially braced structures are doomed to fail once the loads are applied. There should be no compromise on this.
• Any modifications or alterations/additions to a structure should be inspected in conjunction with the relevant Rational Design of such additions or modifications.
• Property owners must be made aware that roof structures must be checked regularly, according to a vital clause in the Construction Regulation 9(4) of 2003.
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ROOF ERECTORSPoorly trained and unqualified artisans, unfortunately, feature at the core of the problem. Their lack of understanding of the basic Roof Erecting Principles and Procedures has led to a multitude of bad practices in the industry for many years. The proliferation of these bad practices, over the years, has resulted in many roof structures becoming ‘monuments of construction inadequacies,’ in direct contradiction to basic design assumptions. We are today witnessing the inevitable after-effects of such structures that do not perform over the long term.
Proper and adequate training of artisans still remains one of the main challenges facing the industry, and it is a serious matter that needs to be addressed urgently and thoroughly. Until this problem is fully resolved, failures of roof structures will likely become more prevalent in the future.
ROOF INSPECTORSDedicated and passionate roof inspectors have, for many years, been mentors to some roof erectors. They have provided assistance, guidance and unofficial training on site to many roof erectors – without any compensation. (And this will undoubtedly remain so until adequate, official training is fully in place.) This has subsequently resulted in the inspector being viewed as the ‘quality controller’ for these ‘contractors.’
One could perhaps hope for the introduction of compulsory written and practical tests, which would have to be successfully completed by currently accredited erectors before their annual ITC-SA membership can be renewed.
Or, and this is my opinion, it warrants reconsidering the way in which roof erectors are evaluated for their competency to be accredited with the ITC-SA to begin with, as, in my experience, too many do not meet the requirements and expected standards.
SAFE ROOFSThe following six points form a very simple guideline that might help in establishing criteria for a ‘safe roof’:
1. All trusses must be erected straight and plumb.2. Ensure that all bracing, as per the design requirements, has
been installed.3. All multiple-ply girders must be bolted and nailed, or
preferably screwed together, in accordance with the SANS10243 requirements and the ITC-SA standards.
4. All cleats must be fully bolted and all truss hangers fully nailed and bolted where required.
5. Torsional restraints must be installed at girders for all incoming supported trusses, as per the design specifications.
6. Fly rafter restraints must be installed to all truncated trusses and truncated girders.
Note that the above points include a substantial amount of ‘finer detail’ that must be complied with in order to make them effective. The fine print on these details must be thoroughly studied and carefully applied.
For more information, the author can be reached via e-mail to: [email protected].
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GET EXPERT ASSISTANCEWhen a roof is found to have any sort of structural damage or has suffered partial failure, it is important to immediately get the right professionals and competent persons involved to address the problem. When matters have reached this point, getting a general contractor or regular roofing contractor involved will in all probability not be of much help. From experience I have found that, although out of a genuine desire to help, general contractors without the required specialist knowledge more often than not aggravate the issue rather than improve it.
ROLE OF THE PROPERTY OWNERAn important point that warrants discussion is the application of the Construction Regulations of 2014. Despite these Regulations having been Gazetted more than 10 years ago already [reference Construction Regulation 2003 9(4)] very few property owners are aware of certain clauses that affect them – until a structural failure occurs and a claim arises.
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roof damage When faced with structural roof damage due to poor design, installation or inspection, there are some crucial steps to take, Stian de Jager advises.
Here he shares some specific do’s and don’ts with SA Roofing. Article by: Stian de Jager, Engineer, Roof Inspector, and Founder of De Jager Roofs Business Trust
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As part of the Occupational Health and Safety Act 85 of 1993 and Construction Regulations 2014, Section 11(2) states:
“An owner of a structure must ensure that:
1. Inspections of that structure are carried out periodically by competent persons in order to render the structure safe for continued use;
2. That the inspections contemplated in a) above are carried out at least once every six months for the first two years, and thereafter yearly;
3. The structure is maintained in such a manner that it remains safe for continued use;
4. The records of inspections and maintenance are kept and made available on request to an inspector.”
Even though legal claims pertaining to the above depend very much on evidence to prove negligence, which might be hard to prove, owners of commercial properties are urged to comply with this stipulation to ensure safe working environments and to avoid any possible claims.
Roofs found to be most susceptible to structural failure are large span (over 10m) timber roofs with concrete roof tiles. The upside to this is that there is a reduced risk for most residential roofs, but on the other hand this includes most commercial buildings, which is worrisome enough.
IMPORTANT FOR STRUCTURAL ROOF REPAIRS
INITIAL MEASURES
• The very first course of action to take when any structural defect or failure of a timber roof is spotted is to vacate the affected area right away and restrict access to it. Keep in mind that this could be a much larger area than it first appears, so it is advisable to vacate the entire area underneath the damaged roof.
• As mentioned before, immediately contact the appropriate competent persons who specialize in structural timber roof failures. Note that a professionally registered structural engineer will have to oversee the repairs and approve any remedial works, so that a new certificate for the roof can be issued after repairs.
• It is also a good idea to check that the professional structural engineer has adequate professional indemnity insurance and has experience in this field. Most are happy to provide proof of this if requested.
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SOME UNCOMMON COMMON SENSE
• With structural damage to timber roofs, the sagging down of the bottom cords in certain areas is very common. Emergency props need to be installed underneath the failing members but should not be propped back into position yet. I have encountered general contractors who have tried to help by doing this, but in the process they merely disturbed the already fragile roof structure even further. Such practice is dangerous and can initiate catastrophic failure. The purpose then of the emergency props, is simply to avoid further sagging until loads can be safely removed from the roof. When the roof loads are removed, members can be lifted back into position.
• When removing the main roof loading (e.g. concrete tiles), it is crucial to remember to do it symmetrically, starting on the area that is affected the worst.
DURING REPAIRS
• Any remedial details have to be clear, drawn up or approved by a competent engineer, and carefully applied.
• The use of wood screws (anodized hex head) instead of nails is encouraged for much better holding strength.
• Where steel nail plates have been torn out of tension members, plywood gusset plates with screws are a good solution when the members are back in position.
• In some older roofs, even though the trusses might have been prefabricated, there are often large areas with no trusses or non-triangulated trusses. This is often found at short setback hip-over-valley areas, and some trusses will have to be purpose-made for this. Often, the appointed engineer will specify the required member sizes, and this can be given to a reputable roof truss manufacturer to fabricate or make on site according to the specification.
• Special attention needs to be given to all girders, not just those in an affected area. This is because, should any inadequacies remain in other roof areas after repairs have been done, the next weakest link may suffer failure. Restraining the girder top cords is of paramount importance, along with ensuring that the multiple plies of girders are acting as one and have not delaminated.
ADDITIONAL CHECKPOINTS
• Also important to consider is the general design of the roof. It is common for the engineer to insist on the redesign of some trusses, and especially girders, to make sure the original design was adequate. If it is found not to be, he will prescribe the relevant remedial. In severe or extreme cases, he may advocate for truss or girder replacement.
• Before reloading the roof, it is crucial that the Competent Person/Engineer inspect and approve the structure with its repairs. Again, the roof needs to be loaded symmetrically and the structure monitored during this process.
• Finally, don’t be afraid to insist on the credentials, proof of indemnity insurance and experience of the team you choose for your repairs. It is our responsibility as professional members of the industry to improve it for the good of all, but I encourage the end user to hold industry members accountable by insisting on verifiable credentials.
The photographs accompanying this article are examples of good remedial details, adequately installed. It is important to remember that the cost of doing it right the first time is always much less than having to redo it later.
For more information, the author can be reached via e-mail to: [email protected].
APR IL 201620
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Features• Superior thermal insulation• Air-tightness• Watertight sealing• Low weight• Adds reinforcement to structures• Ease of application
Rigid polyurethanes offer a versatile array of application methods of all construction requirements, be it in the form of sandwich panels or sprayed-on foam.
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When a thermo-active element is incorporated into a concrete ceiling, this is offset by part of the building itself to regulate heat. This technology produces
extremely energy-efficient cooling and heating in modern buildings that, in some cases, can make them eligible for passive house certification.
Typically, though, the drawback is that the sound-reflecting surfaces of a concrete ceiling mean poorer room acoustics due to longer reverberation times. When acoustic absorbers are subsequently fitted for sound insulation, however, they often have an adverse effect on the convection of air needed, which then considerably reduces the efficiency of the cooling and heating capacity.
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Sound absorbers in concrete ceilings
Concrete ceilings with thermo-active elements can be very energy efficient in terms of heating and cooling, but often pay the price with poorer room
acoustics. But acoustic absorbers, in turn, can negatively impact the heating and cooling capacity. In this article, Germany-based ceiling solutions specialist, Innogration GmbH, shares how they’ve effectively overcome the problem with
an innovative solution from BASF.
Fully integrated, thermally active ceiling Ceiltec® from Innogration GmbH with strip absorbers made of Basotect®.
APRIL 201622
The innovative Ceiltec® thermo-active prefabricated concrete ceilings from Innogration GmbH counter this challenge by using BASF’s Basotect® sound-insulating melamine resin foam.
MULTIFUNCTIONALThe integration of Basotect® in the recesses of the Ceiltec® prefabricated ceiling gives the thermo-active concrete ceiling outstanding multifunctionality with, at the same time, excellent acoustic properties. Even a small coverage of the ceiling (e.g. 10% - 15%) produces a significant reduction in the reverberation time in the room.
Basotect® is a very versatile foam, and its high sound absorption capacity creates a pleasant acoustic experience. And, because it is non-flammable, it is also an important material for fire protection in modern buildings. In addition to this, because it has an extremely low density and does not contain mineral fibre, Basotect® is very easy to install in the recesses provided in concrete ceilings.
“The demand for multifunctional structural elements providing both a good indoor climate and improved room acoustics is steadily growing,” explains Thomas Friedrich, CEO of Innogration GmbH. “The integrated Basotect® strip absorbers in the prefabricated Ceiltec® ceiling mean that the system offers a holistic solution – heating and cooling with the concrete surface but also effective sound absorption on the otherwise sound-reflecting underside of the ceiling.”
ARCHITECTS IMPRESSED BY PRACTICAL SUITABILITYInnogration GmbH has already fitted a number of office and administration buildings in Austria, Germany and Switzerland with Ceiltec® concrete prefabricated ceilings, including the Smarthouse in Munich, the Kreativpark office building in
Karlsruhe, and the Institut Heidger in Osann-Monzel an der Mosel.
It was in the Institut Heidger where Innogration held a joint workshop with BASF in October 2015, titled “Cooling, heating and acoustics in the modern office world.” This provided an opportunity to discuss the challenges faced today by component-activated buildings and offered practical solution concepts for acoustic design.
The ultimate highlight of the presentation was a hands-on opportunity for architects and planners to experience for themselves the attractive room acoustics in the office and laboratory areas.
“Innogration GmbH’s Ceiltec® thermo-active prefabricated concrete ceilings fitted with Basotect® embody a new trend in the modern office environment and are an example of how the high requirements on energy efficiency, acoustics and design can be met,” commented Dr. Normen Langner, Bilfinger Bauperformance GmbH, in summing up the successful outcome.
For more information, visit www.basf.co.za.
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ABOUT BASOTECT®
Basotect® foam has a unique range of properties:
• Its base material makes it flame-retardant and abrasive; it can be used at up to 240°C and retains its properties over a wide temperature range.
• Because of its open-cell foam structure, it is light, sound-absorbing, flexible even at low temperatures, and thermally insulating.
• Basotect® is a registered trademark of BASF SE. • www.basotect.com
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APRIL 2016 23
11 - 12 August 2016, Cape Town International Convention Centre
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CLIMBING TO NEW HEIGHTS INTHE WESTERN CAPE’S CONSTRUCTION INDUSTRY
www.cape-construction.co.za
• Meet professionals from the public and private sector from the entire construction value chain
• If you are a supplier or service provider and want to be a part of the Western Cape construction industry get in touch to sponsor/exhibit and expand your business network!
What to expect?
3500+ attendees
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Contact us todayand quote CCESARto book your space
[email protected] 021 700 4356
CapeConstruction Cape-Construction @CT_ConstructionJoin the conversation
Marley Building Systems is part of the worldwide Etex Group and is a leading provider of roofing and cladding solutions in Southern Africa. The Etex Group is an
industrial concern that produces and markets high-quality building materials. With headquarters in Brussels, Belgium, the group currently operates 123 factories and 116 subsidiaries across 44 countries. With Etex’s DNA at its core, Marley Building Systems brings to the market globally proven innovations and sustainability know-how.
Above all, Marley Building Systems has been a pioneer of the South African building sector for more than 60 years. The company’s success has been achieved largely through the renowned Marley Roofing brand.
INNOVATIVE APPROACH TO ROOFINGIt is this track record that informs the company’s approach to roofing. Marley Business Systems sees the roof as a key architectural feature, equally deserving of sustained technical innovation and aesthetic development to ensure harmony with evolving contemporary tastes and sensibilities. With this approach in mind, the company has extended the roofing range to include a competitive range of clay tiles with an international pedigree: the Canudo, Portuguese and (Advance Premium) Marseille tiles.
This range boasts a diversity of sophisticated shades, warm tones, elegant contours and classy finishings that will suit a variety of architectural styles and customer preferences. A comprehensive array of complementary fittings and accessories completes the offering.
Like all of the company’s products, these clay tiles are subject to a rigorous quality control process at various stages of production. The process is overseen by highly qualified personnel, supported by a state-of-the art laboratory.
Local operations, in line with the practice in international sister companies, will continue to seek ways to reduce the amounts of raw materials, water and energy used in manufacturing and distribution. In the process, the company will also be helping its customers reduce their carbon footprints with eco-friendly products and solutions.
FOR MORE INFORMATION:
Marley Building SystemsIsaac Simelane – Architectural and Specification Manager (t) +27 11 3162121(c) +27 82 771 2571
Marley Roofing’s new clay tiles – a class actMarley Building Systems, through the well known Marley Roofing brand, has introduced a competitive clay tile range that is sure to satisfy a broad range of architectural styles and client preferences.
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APR IL 2016 25
DO YOU HAVE A GREAT PROJECT OR STORY TO SHARE WITH SA ROOFING READERS? Send your article and high resolution images to [email protected] or call 0861 727 663 for more information.
YOUR PRINT MEDIA PARTNER OF CHOICE, SUPPORTING LOCAL TRADE. CONTACT US: [email protected] / 0861 727 663 / www.trademax.co.za
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10 - 11 May 2016Gallagher Convention Centre, Johannesburg, South Africa
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Over 180 exhibitors showcasing technologies and services
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Newlok™ is specifically designed for use on low-pitched roofs and to withstand high winds. Safintra recently approached LCP Roofing to facilitate a Newlok™
information session for their staff, which LCP Roofing gladly expanded to further include their clients and suppliers. “It’s important to us that our clients know about new products on the market and that they understand how these can benefit their projects,” comments Lyndsay Cotton, General Manager of LCP Roofing (Pty) Ltd.
Safintra brought along their Newlok™ mobile mill, steel coil, mechanical seamer and 90˚ hand crimper to showcase the production process of the Newlok™ sheeting, roll-forming the profile from coil to installation. Hilti South Africa was also present, demonstrating their roofing-related tools.
UNIQUE PROFILE AND CLIPPING SYSTEMMark Farrell, Safintra’s Johannesburg Branch Manager, demonstrated the roll-forming process by using the Newlok™ mobile mill to produce the sheeting, highlighting its unique profile and clipping system. What differentiates the Newlok™ profile is that it can be interlocked either with a snap mechanism, or with a snap-and-seam mechanism. Whether snapped together or snapped and seamed, the two-part clip allows natural thermal expansion and contraction without unclipping between purlin supports.
This makes Newlok™ a profile that qualifies as a concealed fix system (hidden anchoring) when snapped together, as well as a standing seam profile (snapped and seamed – either by hand crimping or mechanically). Both methods allow for thermal movement; however, the standing seam configuration provides hold-down strength in excess of 3kPa on negative wind uplift.
While Newlok™ is ideal for long spans on commercial and industrial buildings, due to the system’s ability to expand and contract as temperatures fluctuate, it also finds application in residential settings. It is specifically designed for low-pitched roofs and is fastened on the underside of the sheeting with clips – not pierced with traditional fasteners. This makes for completely watertight sheeting, even at very low slopes. The 50mm rib height also makes for optimal water shedding capabilities at slopes as low as 1.5 degrees.
LCP Roofing provided a sample roof structure onto which the newly rolled Newlok™ sheets were fastened by the LCP Roofing sheeting team. “The sample roof provided an interactive and tactile experience for our guests, who could experience the roof structure close to the ground and get up close and personal with the sheeting and clip system,” says Cotton, adding, “The fixing of the sheets was a prime showcase of the Newlok™ profile in action. Guests could see how the male-female joints easily snapped into place and how the clips held everything together for a smooth, sturdy surface with no piercings. Safintra also demonstrated their hand crimper, for seaming eave and ridge sheets, as well as their mechanical seamer, which is ideal for seaming the entire length of the sheet.”
CONCEALED FIX The day’s session highlighted a number of practical scenarios and raised awareness of the unique roofing requirements presented by the South African landscape. “Concealed fix roof sheeting has become a firm favourite among specifiers, but has, until now, not been well suited to the high wind environments experienced in exposed, newly developed areas,” says Andri Pretorius, LCP Roofing’s Operational Director. “Presently, most concealed fix offerings readily available inland are 700mm wide and, due to changing climatic conditions, need to be positively fixed on both apices and eaves, thereby negating the primary advantage and purpose of concealed fix roof sheeting. Typical residential applications make 700mm-wide sheeting problematic to fix and finish off neatly as well. Fitting a 445mm-wide sheet on a complex residential roof will also be easier from a labour perspective,” he adds.
Steel roofing is both cost effective and it contributes to the overall sustainability of a structure, since metal roofing can be 100% recycled at the end of its useful life. “Newlok™ is a truly innovative addition to Safintra’s roof sheeting range, and in turn, to ours at LCP Roofing. As keen advocates for innovation, we are proud to offer our valued customers the multitude of benefits that come with the Newlok™ system,” remarks Pretorius.
Eyes locked on NEWLOK™
Newlok™, Safintra’s latest concealed fix roofing product, took centre stage in a recent interactive information session hosted by LCP Roofing.
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Safintra’s Newlok™ mobile mill in action.
APRIL 2016 27
SUPPORTED AND ENDORSED BY: • SATAS (SOUTH AFRICAN TECHNICAL AUDITING
SERVICES)
• SAWPA (SOUTH AFRICAN WOOD PRESERVERS ASSOCIATION)
The Guide to Thatch Construction in South Africa is a must for homeowners, thatching contractors, building contractors, architects, engineers and
certification bodies. At nearly 100 pages, colour photographs complement information and explanations of the requirements under the SANS10407 (Thatched Roof Construction) Specifications, to which all thatch roofs must adhere.
WHY THIS GUIDE? In the words of TASA, thatching is no longer a craft that gets transferred from father to son. Nowadays, young people are forced to look for better opportunities in other employment sectors or choose formal education to sustain themselves.
In addition, the thatch industry started feeling the effects of unprincipled contractors who desired to make a ‘quick buck’ by doing low-quality thatch roof work before disappearing soon afterwards. A substantial number of complaints from the public followed, compounded by damages suffered as a result of unpaid insurance claims due to extremely poor workmanship. TASA was compelled to impose radical measures to regulate the thatch industry.
At the same time, the development of this Guide presented an opportunity to meet the growing need amongst all stakeholders for definitive standards on the erection and maintenance of thatched roofs. Moreover, it became extremely necessary in order to determine the level of competence of newcomers to the thatch industry.
OBJECTIVES OF THE GUIDEThe Guide serves as a reference and supporting document, in compliance with the requirements of the South African National Standards. Practical in nature, the Guide explains the materials, processes and test methods to be used in order to comply with those requirements.
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launches Guide to Thatch Construction in SA
TASA, the Thatchers Association of South Africa, is proudly celebrating its 10th anniversary. At the same time, the Association is introducing
the much anticipated Guide to Thatch Construction in South Africa, a milestone accomplishment and the pinnacle of its work to date.
APRIL 201628
The Guide consists of explanatory photos, illustrations and descriptions that are plainly drafted so that everyone can understand the terms contained therein – even illiterate craftsmen and uninformed customers. And yet the nature of the information is indispensable, extending and applicable to professionals such as engineers and architects, as well as other relevant parties like banks, insurance companies, municipalities, etc.
CONTENTThe Guide is divided into different categories and covers all facets of a thatched roof. It begins with the different definitions as set out in the National Building Regulations, namely project process, roof structure, general installations, maintenance of a thatch roof, etc.
Because of the enormous effect it has on the quality of the end product, attention is also given to the specification requirements, handling and storage of the raw material.
HOW TO OBTAIN THE GUIDE The Guide will be accessible to any and all interested parties – at no charge – via download from the TASA website or electronic file exchange. (The TASA office can be contacted for assistance.) It is a ‘dynamic/life’ document that will be updated annually as methods and technologies improve and the National Building Regulations are amended.
The Guide to Thatch Construction in SA will formally be launched at a special TASA Annual General Meeting and birthday celebration, on 23 April 2016. During the event, TASA members with continuous membership for the past 10 years will be honoured; without their valuable input and support this Guide would not have become a reality.
TASA members will also be awarded cash prizes and certificates in a TASA photo competition covering the following categories:
• Largest single structure• Most aesthetic structure• Smaller structures (lapas, etc.)• Funniest thatch photo
SA Roofing is proud to support the thatch industry and TASA’s efforts, and will be awarding a media prize to the best thatch project submitted to us. SA Roofing will also be sharing pertinent information from the Guide to Thatch Construction in SA with our readers in future editions of our publication.
FOR MORE INFORMATION:
TASA (Thatchers Association of South Africa)Cell: 083 283 8429Email: [email protected]: www.sa-thatchers.co.za
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TASA AND THE ITSTASA is one of the founding members of the International Thatching Society (ITS). This membership, along with its presentation of the ITS Congress in 2014, marked a major achievement in TASA’s history.
South African thatchers are as good as the best in the world. This was proven when the ITS honoured Biggarsberg Thatchers in 2014 and Recon Thatchers in 2015 with awards for “Best Thatched Roof in the World.”
TSRW can install into any roof profile and any pitch. Roof windows are very well-suited to thatch roofs, especially when large eaves shadow the windows below. Roof windows also add to the beauty of exposed beam ceilings.
Since 1988, TSRW has been trusted to install top-quality roof windows that complement thatch roofs. Call us today for a custom-fit window that will further enhance your beautiful thatch roof.
• Specialist manufacturer of roof windows and skylights• Well over 40,000 windows fitted nationwide• Adheres to SANS10400-A and SANS10400-XA• Natural light – with a view• Improved ventilation and heat control
Tony Sandell Roof Windows (Pty) Ltd 12 Ferndale Drive, Ottery, Cape Town, 7800 Tel: (021) 704 1122/3/4Fax: (021) 704 1110Email: [email protected] www.tsrw.co.za
In the majority of cases, homeowners with a thatch roof do not sufficiently educate themselves to what they can and should be doing, to prolong their roof’s lifespan and get the
maximum value and enjoyment from their investment. In actuality, a thatch roof’s lifespan can be increased considerably by taking a few basic steps.
SIMPLE STEPSProbably the most important precaution is simply to keep the roof clear from all trees and shrubs wherever possible. That is because leaves and flowers from trees and plants that have fallen onto a thatch roof often rot on the roof itself, and this rotten material prevents the thatch from drying properly. Various organisms then grow within the rotten material and can cause the thatch to decay rapidly.
Something else that is vital for homeowners to always remember, is the number one rule: If anything about your thatch roof concerns you at any time, call your professional contractor, preferably someone registered with TASA (the Thatchers Association of South Africa), to assess the roof and investigate your concerns. Do not wait until there are leaks in your roof before you call a contractor. It is advisable to build a relationship with your thatcher and ask him to assess your roof regularly. It is often the case that, with a very minor repair done in a timely manner, far bigger and much more costly repairs can be avoided.
Like all roofs, a thatch roof will require general maintenance. But, if the roof is looked after, this general maintenance should not be a frequent requirement. Once a new thatch roof has been constructed, it is a good idea to have it serviced after about one year, to check if there are areas that might need a bit of compaction.
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Similar to how we are able to take control of our personal holistic health, we can also take control of the health of our thatch roof. The biggest problem for thatch roof homeowners, however, is their general lack of knowledge
about thatch roofs and, more specifically, the maintenance thereof. This can and should be addressed with simple yet proper education.
Article by: Liesl Schoonraad of Jason Lucas Master ThatchersPhoto credit: Jason Lucas Master Thatchers
APRIL 201630
Slight shrinkage in the thatch over the course of a year’s exposure to the sun is normal. The contractor should do an overall check to see if there are any problem areas.
After the first year’s check-up, a five-year check-up could require a little more attention. But, if the initial services to the roof were properly done, chances are you won’t develop any major problems for years to come.
DON’T PUT MAINTENANCE OFFToo often, when thatch roof owners need to do maintenance, they decide to leave it for another rain season. And then they ask several thatch contractors, including those not registered with TASA, for quotes. To save costs, the cheapest contractors get appointed. But every thatch homeowner needs to know that the saying, ‘penny wise and pound foolish’ applies to all construction.
Unfortunately, homeowners often appoint non-proven, incompetent thatchers to perform thatch roof maintenance work. Afterwards, the roof might look aesthetically good, but in reality, all the unscrupulous contractors really managed to do was further damage the roof (and this will surface soon enough).
At this stage, the homeowner still thinks he has managed to score a fantastic deal – until the roof starts leaking, or thatch starts sliding out of the ridge capping. It is then that the owner calls in truly competent thatching contractors, only to hear he is now in for major repairs – and costs.
It is very important to always check with the contractor who installed the roof whether the roof still falls under a guarantee. Many TASA-registered contractors give guarantees on their products, because they are not ‘fly by nights’ and have full confidence in the product and service they delivered. As a thatch roof owner, you take the risk of losing the guarantee if another contractor does any work on the roof, so it is best to first check with the contractor who did previous work on the roof.
A thatch roof is an investment that every homeowner should be able to enjoy for a very long time. If the basics in maintenance are properly kept up, homeowners will see the lifespan of their thatch roofs increase dramatically.
For more information, visit www.jasonlucasmasterthatchers.co.za or email the author at [email protected].
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The thatch roof after maintenance work was completed.
Maintenance work being done on a thatch roof – more attention is needed on areas covered by the tree.
APRIL 2016 31
The ‘after’ rendering of this thatch roof installed on a house in Hout Bay does not tell the full tale of the difficulties of the site. The house was built on relatively
sandy ground, making the landscape swamp-like and somewhat unstable. Access to the site location was also difficult.
THE BRIEFThe project brief specified some very particular requirements: The client wanted natural, very light poles. The structure of the roof had to make a statement – an ordinary roof was not going to make the grade; this roof had to be extraordinary and be the focus point of the house. The client also expressed concerns around the density of the roof and having to deal with wind and dust elements, which had to be avoided as far as possible.
TH
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From the outset, this client made it very clear that only the best thatch roof would be good enough for this home. It’s easy to see why Highveld Cape Thatchers received a complimentary letter of satisfaction from
the client upon completion of their work.
APRIL 201632
THE ANSWER Exceptional attention was given to the roof structure to ensure that the demands of the brief would be answered. Approximately 72,000 bundles of thatch were used in the project. Extra care was taken with the poles: Prior to installation, the poles were scoured and cleaned with the bleaching product Timbrite RFU.
In the thatch application, a ‘double stitch’ method was used that resulted in the stitches measuring approximately 5cm apart. This technique gave the roof an incredible gloss-like texture, described by the satisfied client as being similar to a finely woven carpet.
The client wanted the most beautiful and best executed roof in the country. The letter of appointment had made it clear that both client and architect would perform several stringent quality checks during the installation process, and that no imperfections would be tolerated. This was clearly achieved, and is evidenced by the testimonial the client submitted: “The roof looks stunning. We are very pleased with it and glad to have chosen Highveld Cape Thatchers as contractor for this job – very professional service and well done!”
For more information, visit www.highveldcapethatchers.co.za.
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When HP2 Consultants were appointed as project managers for a major
refurbishment planned for Skukuza Airport, they approached Hoffman’s Thatching Specialists to become part of the project team and specifically oversee the thatch work.
By the time Hoffman’s was ready to start with the construction of the new thatch roofs, they faced a major obstacle: It was very early in the year, and the Sabie River, which had to be crossed via a low-water bridge, was in flood. (Kruger National Park authorities usually close the bridge well in advance of any expected flooding, because once the wave of water is on its way, it literally takes just a few minutes for the bridge to be totally submerged.)
TH
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It took exceptional planning to successfully execute this thatch project, which formed part of a broader refurbishment initiative for the Skukuza
Airport that serves the famous Kruger National Park. Hoffman’s Thatching Specialists tells us more.
APRIL 201634
This situation of course presented a major logistical dilemma that directly impacted operations, as the only course of action available to the Hoffman’s team was to follow the road down the river in the direction of Lower Sabie, where they could cross over at the ‘high water’ bridge. But this meant a detour of up to 40 kilometres per round trip. And time was already limited: The opening date for the new airport was by that time scheduled and confirmed, allowing the thatchers barely six months in which to complete the entire installation.
To top it all, this intricate project had to be completed ‘with minimal disturbance,’ as the scope of work fell within a noise- and environmentally sensitive area of the Kruger National Park. What made this restriction very difficult to adhere to, was the fact that the nearby air strip was operational during the thatch installation period. The airport terminal building was not complete yet, but guests who were staying in the Park continued to arrive via chartered flights and were being transported to their quarters by staff from the surrounding lodges. Hoffman’s had to enforce strict noise level measures at all times, but especially while guests were arriving and leaving.
It took exceptional planning and effort from both the company’s management and construction teams to overcome these challenges. But Hoffman’s factored in the potential cost savings in time, and was able to successfully complete the project within the deadline – and without sacrificing on the matchless quality of work that the company prides itself on.
For more information, visit www.hoffmansthatching.co.za.
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FAST FACTS• Approximately 50 tons of CCA-treated saligna gum
poles were used for the timber construction.• About 150,000 bundles of thatch grass were used to
complete the project.• Close to 250kg of tarred treated sisal twine was used.• The entire roof had to be covered with 25mm
galvanized wire netting to prevent baboon damage to the thatch roof.
APR IL 2016 35
This was the challenge set for Etienne Hurter of Summit Builders & Designers cc when
he was appointed to create the Addo Lifestyle Centre (now situated on the main road roughly 10 kilometres before the Addo Elephant Park).
After careful consideration, Hurter opted for a thatch roof to complement the stone feature walls and other natural elements. The result is a building that is not only aesthetically pleasing to the eye, but exudes the warm and welcoming ‘character’ the client had desired.
From early on in the design process, Lucas Quality Thatchers was roped in to help create a dream roof that would serve as the focal point of the building. To design such a roof is one thing – to make it work is quite another:
TH
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Where do you start when tasked with constructing an eye-catching building meant to lure tourists to stop and explore all that it has to offer?
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The specification was for a single thatched roof that would encompass a reception area, conference facility, bar, lapa, private lounge, double-volume restaurant, kitchen, pantry, scullery, and a two-bedroom flatlet. Executing the design was going to be no small feat. But for Abrie Visagie, Lucas Quality Thatchers’ in-house Structural Engineer and Technical Director, the challenge was right up his alley.
SPECIFICSTo start, the engineer’s designs, pole sheets and timber application sheets were all done to make the ± 1,144 m² roof a reality.
The 10m roof span, abnormally high wall plate level, as well as the 8m height over the double volume area necessitated the use of a lattice girder in the ridge and a unique truss design to help carry the weight of the thatch.
The work of two carpenter teams was needed to keep ahead of the programme, and to finish the roof off, an additional large thatching team had to be utilized.
Close to 6,650 man hours and three months later, under the watchful eye of Johan Landman (Managing Director at their George branch), the client’s dream had come true.
For more information, visit www.lucasqualitythatchers.co.za.
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MATERIALS USED• 70,000 bundles of thatch• 3,5km roof poles• 5,7km ‘latte’ for the roof • 12,5km ‘latte’ for the pergolas• In total, approximately 80m³ timber was
used in the roof and the pergolas
Pole layout
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Bertus Nieuwenhuis, owner of Recon Thatchers and also the outgoing National Chairman of TASA (the Thatchers Association of South Africa), takes us on a journey
comparable to ‘a day in the life of the professional thatcher.’ This thatch work was done in a game park, and these images demonstrate the extra lengths that thatchers often go to in order to deliver the top-notch results that make thatch so desirable.
When tendering for a thatch project, Nieuwenhuis explains, it is a natural assumption that there will be reasonable, accessible roads in place to enable travel and transport to the site.
However, clearly that is not always the case. Even with vehicles and equipment made for construction sites, navigating difficult terrains can be tricky, especially when it rains.
In this particular instance, to beat the steep passes, Nieuwenhuis had to dig deep in his pockets and get an oversize truck to help transport the thatch and a smaller construction vehicle. Help does not come cheaply in many of these remote areas.
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All in a day’s work The end product of a quality thatch installation is usually quite
beautiful. The professionals make the neat results look easy. But the effort and work that must first be done to achieve that desired
outcome is often exactly the opposite, as this article shows.
At last – reaching the top of the wetlands.
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For more information, visit www.reconthatchers.co.za.
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The inside of the headquarters.
This is the inside of the dining room, with a 16m diameter, free standing, without a king post.
Phase 1 completed.
Phase 2 completed – after 14 truck tyres had been replaced.
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In fact, in order to consolidate the efforts of industry associations and to optimize their effectiveness, the SAISC has both created new associations and absorbed others.
The SAISC group now comprises ten associations that will work together to help their members grow their businesses and will continue lobbying for them on the plethora of important issues in the relevant government forums and others, says Trinchero. The institutions that are now part of the SAISC are:
• Southern African Light Steel Frame Building Association (SASFA)
• Southern African Metal Cladding and Roofing Association (SAMCRA)
• Powerline Association of Southern Africa (POLASA)• Association of Steel Tube and Pipe Manufacturers (ASTPM)• Steel Window and Door Association of South Africa
(SWADASA)• Southern African Racking and Shelving Association
(SARASA) [currently being set up] • S.A. International Steel Fabricators (ISF)• Steel Tube Export Association of South Africa (STEASA)• Association of Structural Steel Draughtsmen (ASSD)
Trinchero says there is no doubt that the ‘economies of scale’ principle is most apt in these circumstances. “Instead of each of these associations working on its own in an industry where there are many significant challenges, we will all be able to pull together our resources and make sure that we accomplish what has to be done in order to help our industry reach its full potential over the years. There is certainly an economic advantage by working under one roof, but the main advantage
will be the pooling of the brain power of experienced and dedicated people who have the industry at heart and the knowledge to ensure that we are the best that we can be in terms of beefing up the skills of the steel construction industry in southern Africa.”
Trinchero says the most important issue facing the steel construction industry today is the lack of meaningful projects. “This has been our ‘war cry’ for some time and we continue to emphasize the critical importance of releasing projects in terms of the National Development Plan (NDP) and, from a macro political perspective, creating confidence to encourage investment in South Africa.”
He adds that, as a collective, the steel construction industry must, and will, continue to lobby the relevant institutions to ensure that more projects come on stream and that there is a more level playing field in terms of import pricing, which is obviously a crucial element to the success of the local industry.
Trinchero says the International Trade Administration Commission of South Africa (ITAC) is currently processing import tariff amendments to various steel products, which are aimed at reducing the flood of imports into South Africa and levelling the playing fields to some extent. “We are currently embarking on an exercise to provide a full view of our industry to ensure that we have some balance. For example, on fabricated structural steel we may have an import tariff on input material of 10% which is balanced by an import tariff on finished goods of 15%. A survey has been sent out in collaboration with the South African Iron and Steel Institute (SAISI), Manufacturing Circle and the Steel and Engineering Industry’s Federation of Southern Africa (SEIFSA), which will give us an excellent idea of how the industry relates to an initiative of this order,” Trinchero says.
He warns, however, that while designation and localization are very important concepts, they must not create a sense of apathy in our industry: “We must ensure that each and every one of us is competitive in the global sense, as putting structures in place that will help in localization will never take the place of our being able to compete in the global context.”
“We are of the opinion that our newly structured SAISC will be in the position to help our industry to become more competitive, and we invite all those who are keen to make a go of it as the world opens up to us, to make sure that they use the quite unique resources offered by this re-engineered and expanded Institute,” he concludes.
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Southern African Institute of Steel Construction (SAISC) CEO, Paolo Trinchero, says that even though the steel construction industry is currently under
significant pressure, the SAISC is certainly not pessimistic about the future.
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