d39br building refurbishment and maintenance exam · pdf filed39br building refurbishment and...

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D39BR BUILDING REFURBISHMENT AND MAINTENANCE

Exam Preparation

This note is intended to help structure and provide a framework for your revision for

the exam. The undernoted topic labels can be used as core headline areas at the

centre of your reading, revision and preparation. There are of course many

surrounding and related issues that can be embraced in the preparation.

The better exam solutions tend to demonstrate a sound understanding of the

subject matter, generally through diversity and depth of related reading undertaken.

The core and supplementary reading indicated in the module provides guidance in

this. A greater grasp of the subject matter is usually apparent in discursive and

balanced solutions, which addresses the question well. Top quality students, will

show a deep theoretical understanding and practically apply the understanding in

writing with supporting sketches or diagrams where required.

Basic answers tend to be those that suggest a more limited range of reading has

been undertaken, with solutions which often appear superficial. You are required to

support or base your answers on reasoned argument.

Clearly annotated sketches, diagrams and graphs will be awarded with marks,

students should ensure that each component of their sketches are clearly labelled,

any specification details that can be provided as examples of the components will be

positively marked. Good answers should provide fully annotated sketches with a

clear description of the process that the sketch refers to.

Students will be expected to answer 3 questions. The first question from the

section A is compulsory. You will need to select two more questions out of the 4

remaining questions from the section B.

The exam aims to assess many aspects of the course and particularly

the following…

• Section A mandatory question requires students to present ideas regarding

the “change of use” options for a four storey old building in a report format.

o You should be able to provide recommendations for refurbishment of

flat roof and external walling.

o You should be able to link possible use changes with logistics,

location, economic and business factors.

o You should be able to identify challenges and limitations of the

recommended internal refurbishment operations for the given

scenario.

• There are water penetration and flooding problems in the basement.

o How did they emerge and the implications on the building fabric

o A proposal for resolving the issues

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• Warm pitched roof. Whole life costing implications of using warm pitched

roof.

• Access related issues during the maintenance and refurbishment of the

occupied buildings.

• BIM compliance of refurbishment activities.

Practical Tips for Exams Here is a list of practical tips for you to use, the list offers some guidance for you in

planning your exam strategy, it offers tips of things that you can do during the exam,

the list aims to offer practical ways to help you manage your exam experience and

improve your exam technique, the list is not exhaustive and is only mean to act as a

guidance note, you should read the list carefully and plan your exam strategy to suit

your individual.

Read the Questions and Choose you Exam Questions Carefully

• Always read all of the questions properly.

• Ensure that you are clear about the question posed and that you can answer

the specific requirements of the question.

• Students that attempt questions that they have not read and understood

properly or have a poor level of subject knowledge about can provide poor

quality responses as they responses are often not directed at the question

set.

Plan your exam time properly

• Every minute counts!

• Students often under perform in exams as they do not manage their time

well and can often run out of time. This may mean that whole exam

questions are not attempted or responses to exam questions are incomplete

and the opportunity to gain large numbers of marks can be missed.

• Ensure that you spend the appropriate amount of time answering the

required number of questions required for the exam.

• Research shows that the easiest exam marks to obtain are the marks

awarded initially, to gain more marks the quality of your answer must

increase; this is achieved through more detailed discussion of the key points

and /or a wider number of discussion points.

• In simple terms avoid spending your entire time answering one question

really well at the detriment to the other questions that you need to answer.

• Plan your time, a good example would be if the exam requires you to answer

three questions, allow yourself approximately the same amount of time for

each question.

• A good idea can be to complete in your opinion your best question first, i.e.

the one you have the most subject knowledge about. This will help you over

come any nervousness that you are feeling and help you to focus your mind

and increase your confidence levels. As opposed to attempting a question

that you may have less subject knowledge or understanding of and feeling

unsure or unclear about how to approach the question posed.

3

Plan your written response

• Don’t waste time copying out the question posed, use you exam paper as a

reference point for the question, a good idea could be to write a very short

plan of your response, bullet point the key issues you are going to discuss and

then cross them off as you complete each one, this can act as an aid to

jogging your memory and ensure that you do not miss out any important

discussion points.

• Always leave space between each of your exam question responses, this

means that during the exam if you remember a new point you can go back

easily to your response and add in new points or ideas.

• More marks are awarded when the response to the exam question shows the

application of the subject knowledge to the questioned posed i.e. refer you

answer to the scenario provided in the question and make direct links to it.

• Exam answers that provide generic lists of information from the course notes

that do not apply directly to the questions posed will gain limited marks.

• At this stage in your studies you should be able to discuss the subject

material and apply it to the exact question set.

• Please avoid bullet point lists in your exam responses, at this level of study

more marks are awarded for discussion demonstrated through clear

comprehension and full sentences. Only resort to bullet points if you are

running out of time, as anything that you write will be positively marked if it

is applicable to the exam question posed.

Check your responses

• Use all the time allocated to you, if you have time, read through and review

your answers, at this point you may remember something that is relevant

that you want to add to your answer to enhance your over all response to the

question.

Finally

GOOD LUCK!

• Section A mandatory question requires students

to present ideas regarding the “change of use”

options for a four storey old building in a report

format.

o You should be able to provide

recommendations for refurbishment of flat

roof and external walling.

o You should be able to link possible use

changes with logistics, location, economic

and business factors.

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o You should be able to identify challenges and

limitations of the recommended internal

refurbishment operations for the given

scenario.

Recommendation for refurbishment of flat roof

OVER-ROOFING

(Tata catalogue) Trussed rafter system

This system is designed for use on existing roofs that do not have the

capability to support any further load. Instead, factory assembled clear

spanning trusses constructed using a series of purpose made sections are

supported by the existing load bearing walls or columns. Once in place, the

trusses are fixed into the connection plates, braced,and the roof purlins

secured. Depending on the size of roof the spanning trusses will be delivered

as a full unit or in two halves.

Indicative over-roofing design sketch:- a choice of 4 profile/ design

(Tata catalogue) Benefits: Roof upgrade – flat to pitch

• Provides a permanent solution to flat roof failure and moves water

drainage to the outside of the building.

• Framing systems are individually designed and tailored to suit

structural requirements

• There is minimum disruption to building occupants.

• Dramatically upgrades building aesthetics.

• Provides opportunity to easily upgrade thermal performance.

• Life of building considerably extended and future maintenance costs

reduced.

(Lesson 1 slides) Considerations:

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• Structure & condition of existing roof

• Extent & location of services

• Need for fire compartmentation

• Access around building (crane and storage)

• Disruption to tenants

• Programming of works where wall over cladding is also undertaken

Recommendation for refurbishment of external walling

OVER-CLADDING (for less disruption)

(BRM Notes pg 10:6)

Rain-screen systems:

Types: Drained and back-vented – typically metal or composite board

systems supported on a structural frame. The void behind the external

sheeting usually encloses thermal insulation and a ventilated cavity directly

behind the sheeting. This cavity is ventilated through gaps in this outer

sheeting. Condensation or penetrating rain water can drain down the back of

the sheeting where it is directed to the outside at regular flashings, see figure

below.

Requirements:

• Protection – to provide resistance to wind; wind driven rain/ snow;

impact damage and lightening. This protective aspect of the cladding

system probably provides the biggest challenges as the system must

resist a number of different forces, influences and effects.

• Appearance – the cladding finish must provide an acceptable

appearance in keeping with convention and the surrounding

environment. Typically constructed from panels and metal framing

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the completed structure needs to conform to conventional norms and

not resemble a caravan!

• Durability – the completed system must have a life span at least equal

to that of the overclad structure and where possible enhance this

service life. Over cladding is typically undertaken well into an existing

building’s ‘life’, i.e. 50-60 years, with the expectation that it will

extend this life by some considerable time.

• Insulation – most overcladding systems incorporate thermal

insulation to reduce heat loss and deadening to reduce sound

transmission from street noise or rain drumming.

Change of use and its justification – logistic, location, economic and

business factors

Change of use can be at the estate level whereby an entire precinct or area is

re-zoned for different use. For example Singapore’s new Marina Bay is a

reclaimed land and a lot of the conserved buildings which used to be sea

facing is now facing the bay and are no longer functioning based on its

original use as an colonial administrative office or as a pier. For example the

current The Fullerton hotel , Boat House, Clifford Pier etc.

Change of use could also be at the building level whereby the building is

converted to another use entirely. For example in Singapore with the opening

of two Integrated Resorts there is a tremendous increase of tourist arrival.

This resulted in some office buildings being converted to hotels. For example

– Innotel Hotel along Orchard Road.

Possible change of use

1) Hotel

2) Office

3) Service apartment

4) Hostel

5) Apartment for sale

Logistic factors

• Possible change of transportation nodes eg bus interchange , new

subway station

• Change of road network – implementation of expressway which

bypass the building

Location factors

• Possible change of the estate character – downgrading or upgrading

• Inclusion of major employment centre eg financial centres or shipping

companies or petrochemical plants

• New tourist attraction or varsity etc

Economic/ Business factors

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• Change in economic situation – change in purchasing power, income,

tourist arrivals, foreign investment , expatriate arrivals

• New retail innovation or products – competition from low cost carrier

or hotels

Some specific local examples of environmental impact which drives

refurbishment:-

Office

buildings :-

• Re-structuring of economy into more service oriented

industry – leading to an increase demand for high

specifications and technology office building for the

financial sector.

• Older office building without the necessary essential

specifications lose out in terms of competition

Shopping

malls:-

• Orchard Road – a regional catchment within and beyond

Singapore for mid to high end fashion and lifestyle

shopping. To cater to higher spending power several

building owners has recently built duplex store for luxury

brands flagship stores.

• The decline of certain trade or reduced demand for certain

products leading to the re-configuration of shopping malls.

Eg the expansion of Apple stores and decline of DVD, CD

shops.

• 2008 financial crisis – leading to the exit of Carrefour in

Singapore and aggressive regional expansion of other

retailer into Singapore and Asia eg Uniqolo , H&M

• Consolidate of large format department store – exit of

Sogo, Metro and expansion of Isetan, Robinson

• Proliferation of different store format – eg NTUC Finest,

Apple Store, food kiosk etc

Industrial

buildings :-

• Re-configuration to cater to changing industry output

requirement – addition of ramp , loading / unloading bay

Hotel:- • Upgrading of guestroom design to incorporate latest

entertainment and business technology eg wall mounted

Smart TV, wireless internet

• Upgrading of finishes and fittings to keep up with

competition arising from increase tourist arrivals and

higher expectations – eg Mariott Hotel 2012, Pan Pacific

Hotel 2012

Internal refurbishment operations – challenges and limitations

(BRM Notes Section 9.6)

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Challenges & Limitation

• Building structural grid may limit the desired layout of the new

buliding use

• May require additional structural strengthening or underpinning if the

new building use has higher structural loading

• Would disrupt existing user and tenants

• Existing building may be very old and information may not be

available or the existing structural integrity cannot be ascertained

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There are water penetration and flooding problems in

the basement.

o How did they emerge and the implications on

the building fabric

o A proposal for resolving the issues

How did they emerge and the implications on the building fabric

Water Penetration in basement

See documents

• “Luxfoundation Waterproofing”

• “waterbasement 2004”

• “FloodBrochure_v1”

• “BasementFloodingBrochureforweb”

A proposal for resolving the issues


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Other measures

• Waterproofing basement walls – See document “Sika Basement

Waterproofing”

• Surface water drainage

• Sump pump

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• Warm pitched roof. Whole life costing

implications of using warm pitched roof.

See document “English Heritage – Insulating Roof At Rafter Level”

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Whole Life Costing

Definition: the systematic consideration of all relevant costs and revenues

associated with the acquisition and ownership of an asset. In construction,

this is expected to take into account capital or procurement costs such as

• purchase or leasing,

• interest

• fees, and

• initial construction or major refurbishment,

plus the recurring or occupancy costs such as:

• rent

• rates

• cleaning

• maintenance, repair, replacement / renewal

Warm pitched roof whole life costing

Initial cost

Refurbishment cost is higher than cold roof but possibly cheaper than over-

roofing.

Recurring cost

Rent – may attract higher rental as warm roof is preferred as compared to

cold roof

Cleaning – cleaning cost is no different from that of cold roof. Usually only

the roof covering and rain water pipes needs to be cleaned

Maintenance – as warm roof helps to reduce condensation there will be less

issue of water penetration or dampness issues. Hence long term

maintenance and repair cost is reduced.

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• Access related issues during the maintenance and

refurbishment of the occupied buildings.

Access related issues during refurbishment of an occupied building



(BRM Notes Section 6.5.1,6.5.2)



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(BRM Notes Section 10.5) – over-roofing

(BRM Notes Section 12.6) – constructional factors

Access related issues during maintenance of an occupied building

(BRM Notes Section 6.4.1)


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Especially BRM Notes Section 12.14!!!

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• BIM compliance of refurbishment activities.

What is BIM

(Autodesk) BIM is a process that involves creating and using an intelligent 3D model

to inform and communicate project decisions. Design, visualization, simulation, and

collaboration enabled by Autodesk BIM solutions provide greater clarity for all

stakeholders across the project lifecycle. BIM makes it easier to achieve project and

business goals

Building Information Modeling (BIM) is a process involving the generation and

management of digital representations of physical and functional characteristics of

places. Building Information Models (BIMs) are files (often but not always in

proprietary formats and containing proprietary data) which can be exchanged or

networked to support decision-making about a place. Current BIM software is used

by individuals, businesses and government agencies who plan, design, construct,

operate and maintain diverse physical infrastructures, from water, wastewater,

electricity, gas, refuse and communication utilities to roads, bridges and ports, from

houses, apartments, schools and shops to offices, factories, warehouses and prisons,

etc.

(BCA)

Building Information Modeling

• Is a process from silo-based environment to collaborative and coordinated practice

It is

• a data rich digital model

• Object based relational database

• a model with Intelligent objects

What can BIM do / Benefits of BIM

(BCA)

• Collaboration

• Review clashes

• More efficient process – faster decision making, tighter check on compliance

with code, seamless flow for the entire building life cycle etc

• Integrate information / database

• Improved collective understanding of design intent

• Improved overall project quality

• Reduced conflicts during construction

Singapore BIM development

• July 2013 – mandatory architecture BIM e-submissions for all new building

projects >20,000sqm

• July 2014 – mandatory engineering BIM e-submissions for all new building

projects > 20,000sqm

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• July 2015 – mandatory architecture & engineering BIM e-submissions for all new

building projects > 5,000sqm

BIM compliance and refurbishment

• BIM compliance is usually not required for refurbishment project as the scope

tends to be smaller as compared to new construction. Government roll out of

BIM compliance tends to focus on large scale building projects as they would

have the financial resources to do so.

• BIM compliance requires the investment of financial resources on BIM compliant

software and systems. It also requires the training of human resources as well as

the regulatory regime to mandate the use of BIM.

• Increasingly refurbishment needs to be “green” and value for money. Hence BIM

is very suitable in capturing geometric and non-geometric information which

could assist decision making using whole life cycle calculation. BIM is also

collaborative and serves as a good platform for integrated design approach.

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Term Definition

Compare Look for similarities and differences between; perhaps reach

a conclusion about which is preferable

Contrast

Set in opposition in order to bring out differences Criticise

Give your judgement about the merit of theories of opinions

or about the truth of facts; back your judgement by a

discussion of evidence or reasoning involved

Define

Set down the precise meaning of a word or phrase. In some

cases it may be necessary or desirable to examine different

possible or often used definitions

Describe Give a detailed or graphic account of

Discuss Investigate or examine by argument; sift and debate; give

reasons for and against. Also examine the implications

Evaluate

Make an appraisal of the worth of something, in the light of

its truth or usefulness. Include, to a lesser degree, your

personal opinion

Explain Make plain; interpret and account for; give reasons for

llustrate Use a figure or diagram to explain or clarify, or make clear by

the use of concrete examples

Interpret Expound the meaning of; make clear and explicit, usually

giving your own judgement also

Justify Show adequate grounds for decision or conclusions; answer

the main objections likely to be made to them

Outline

Give the main features, or general principles, of a subject,

omitting minor details and emphasising structure and

arrangement

Relate a) Narrate - more usual in examinations

b) Show how things are connected to each other, and to what

extent they are alike, or affect each other

Review Make a survey of, examining the subject carefully

State Present in a brief, clear form

Summarise Give a concise account of the chief points of a matter,

omitting details and examples

Trace Follow the development or history of a topic from some point

of origin

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Sample Answers

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DEFECTS LIKELY CAUSES REPAIR AND MAINTENANCE TIPS

Mechanical damage due to

objects dropped on tile surfaceConduct regular inspection

Improper installation of tiles

onto roofReplace damaged or loose tiles

Tiles dislodged by strong winds

Corroded wire used to tie tiles

to battens

Engage specialist to jet wash the

roof surface

Spray anti-fungal solution on

roof surface

Termite-infestationRemove and replace all affected

timber units

Decay of timber in contact with

damp brickwork

Apply anti-termite treatment

under base slab

Apply anti-termite treatment to

wood

Use properly seasoned wood

Apply remedial treatment to

wood, eg. drying out,

application of wood

preservatives

Choked roof gutter due to fallen

leaves and branches

Cover gutter with appropriately

sized wire mesh

Undersized or blocked rainwater

outlet

Regular inspection of gutters

and gutter supports, once a

week, especially if there are

trees in the vicinity, to clear

away leaves which prevent

water from draining away

Cracked gutter due to wear and

tearRemove debris from all gutters

Insufficient fall in gutter

Check that drainpipes are

draining properly by water

testing them

Paint roof gutters with

insecticide paint to prevent

mosquito breeding

Local tropical conditions of

constant high humidity and

heavy rainfall

Apply protective metallic

coatings or paints to steel

sheeting

Deposits of wind-borne salts

and atmospheric sulphur

particles and other pollutants

Consult specialist for repairs

Ponding in sheet metal roofing

Inappropriate gradient (fall) of

roofing profile, preventing

speedy drainage of rainwater to

gutter and rainwater drainpipes

Ensure appropriate gradient in

metal roofing, according to

system selected

Leaks due to cracked, loose clay

tiles on pitch roof

Stained clay tiles on pitch roof Growth of algae

Rotting supporting timber rafters,

purlins or battens

Leaks at roof gutter

Rusting and corrosion in ferrous

metal roofing (especially in

profiled steel sheeting used to

line soffit of projecting eaves and

underside of projecting canopies)

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Question 2

The findings from a detailed condition survey of your client’s building have identified a serious issue

with condensation and water penetration related to the pitched roof. Provide your guidance and

recommendations to your client on the following:

a) The significance of the defects, i.e. explaining how these defects came about and how you

would determine their priority when considering remediation.

b) A long term maintenance plan to reduce the risk of recurrence.

Answer

Condensation is the process by which water vapor in the air is changed into liquid water. In other

words, the water in the air, a gas known as water vapor, from your “hot” atmosphere gets in contact

with a “cold” surface. This caused the water vapor to condense, or turn into its liquid form i.e. water

vapor, from your hot shower cooled when it met the surface of the cold mirror and would noticed it as

moisture or beads of water and fog that has formed on the mirror.

Examples of physical breakdown

The possible cause of condensation and water penetration could be due to a physical breakdown,

specific failure or impaired performance of material, component or element such as waterproof or

weatherproofing elements, skins or coverings, e.g. bituminous felt roofing; slate tiling; external

rendering; paint finishes from the closures at openings, e.g. water bars; sealants; drips of the installed

dormer(s), windows and doors at the pitched roof.

Failure of the M&E services to and from the building, e.g. hot and cold water; gas, electric, foul

drainage might also resulted in the variance of inner building temperatures that would alter the

percentage of moisture, where the relative humidity (RH) will be affected.

Consequences of failure

Depending on the scale and magnitude of the issue(s), it can be an economic disaster, either direct or

indirect as it would involves financial costing, depending whether it is short or long term, i.e. a water

leak at roof level may take many years to cause (costly to repair or replace) timber decay in roofing

timbers.

From technical aspect, consequent failure of components, elements or building services due to an

isolated building failure, e.g. water ingress can seriously impair or damage electrical services and we

may need to re-run the electrical services.

We might expect legal claims or action initiate by members of public, staffs, users, Tenant(s), etc.

arising from any injury and/or impairment sustain due to the noncompliance. Where the breach or

injury is serious, these costs may outweigh the maintenance bill many folds.

Lastly, the Tenant(s), staff(s), etc. would suffer loss of use or enjoyment of the building as result of

failure.

Disturbance & interruptions to building in use:

- Decanting – the removal (partial, full or phased) pf any occupants within the building.

Decanting arrangements can be highly disruptive to normal site work patterns as noise, dust,

material and labour movements have to be coordinated with these third parties.

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- Partial closure – similar to decanting, where part of the building is cleared of tenants during

phased works.

- Restricted working hours – in some highly sensitive environments, e.g.

hospitals, MINDEF establishments, banks, etc. working hours may require to be limited.

Typically working after normal working hours; weekends; nights; public holidays, etc. is

expensive and can be unpopular with contractors.

Noise and dust control: where the rectification works is being undertaken within or close to an

occupied building; or where sensitive equipment or finishes are being preserved; or where there are

local environmental restrictions (statutory) there may be a need to strictly control noise and dust

emission from the site. These additional controls add cost in term of equipment, management and

(indoor) air quality monitoring.

Problems Areas

Leaks: roof lights have to be effective sealed around their perimeter to prevent moisture penetrating.

In addition to an effective perimeter water seal, overlying roofing membranes require to be properly

lapped to prevent water being directed into the roof.

Condensation: glazed (even double and triple glazed) roof lights represent a considerable thermal

bridge, resulting in colder internal surfaces and the formation of condensation. This is a particular

issue, where the glazing emits to a cold night sky.

Heat gain: increased internal temperature can arise during sunny periods

Ventilation: in order to reduce the risk of condensation within these thermally upgrading roofing

elements it may be necessary to introduce ventilation to the underside of external membrane,

sheathing or cladding. In order to accommodate this additional insulation and ventilation, it may be

necessary to increase the thickness of these elements.

Structural alternations

Repairing defective structural members:

- Decaying joist ends or rafter feet – timber decay as a result of long term wetting can result in

a need for joist ends to be replaced. Replacement requires that the existing roof loadings be

transferred from sound timbers to the wall or vertical columns until timber is reinstated.

- Sagging floor joists ties/purlins – over time, overloaded or wide spanning floor or roof

timbers can sag. Remedial works to these timbers may require that the applied loads be

temporarily diverted.

Structural requirements (Structure) Condition:

- Deteriorated – materials can deteriorate for a number of reasons, e.g. exposure to weather/

water; excessive loading or extremes of temperature, and careful assessment needs to be

undertaken to ensure that affected structural components will effectively support the existing

or/and any new loading.

- Minimal repairs required – some damage may appear worse than it is. By way of example:

joist ends damaged by water ingress may cause the whole floor to sag or move. However,

limited replacement of the joist ends may resolve the problem rather than complete removal

and replacement.

Thermal Insulation (Energy) Key

elements:

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- Main walls – insulation can be applied to the internal or external faces of outer walls or

introduced as cavity fill.

- Roof – Insulation (typically mineral or rock wool quilt) is laid between and over ceiling

joists. In major roof refurbishment works, where slating/tiling and roofing battens are

replaced, consideration could be given to introducing sarking insulation, laid over existing

rafters.

Typical external refurbishment

Re-roofing - Recycled/ artificial slates – on the pitched roofs, it is common to strip off existing (aged)

waterproof covering (slates and tiles) and replace with lightweight, recycled or reconstituted

slate systems.

Window replacement: typically undertaken as part of an overall thermal upgrade of the building.

However, PVC-U windows are also routinely introduced when older timber or metal windows are

approaching the end of their service life.

Typical internal refurbishment

- Improved ventilation – to reduce the risk of condensation from moisture laden air

transferring throughout the building

Dampness and structural repairs:

- Timber decay eradication – decayed timber is structurally unsound and potential unsafe.

Eradication can range from the removal and replacement of a few floor boards to the

complete removal and replacement of joists, wall plates and floor boards.

- Condensation and other dampness control – this is an extensive area. Typically the remedial

measures must include eradication or reduction of the moisture source and replacement or

repair of any affected materials and components. Refurbishment measures include:

introduction of mechanical/passive ventilation; improved drainage; timber decay eradication

Upgrading pitched roofs Coating existing covering: application, typically involves careful cleaning of the existing substrate

followed by a two coat application incorporation a reinforcing fabric. The correct installation of this

reinforcement is vital to prevent excessive movement and cracking of the completed membrane due to

the high variations in temperatures experienced by roof surfaces.

Replacing roof coverings:

- With same – complete removal of the existing tiling/ slating system will be required. Battens

will only need replacing where these have deteriorated.

- With different – the existing roof coverings and secondary supports (battens, framing, cleats

etc.) will need to be removed to expose primary structural support. Where a heavier water

proofing system is to be applied, this primary structure (rafters, trusses) may need to be

stiffened, braced or upgraded to accommodate this increased load.

Thermal upgrading:

- At ceiling level – mineral wool quilted rolled over and between ceiling joist. Care needs to

be taken to ensure that effective eaves and ridge ventilation is installed and is clear of

blockages.

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- Sprayed-on insulation to underside of pitched roof deck – typically a foamed plastic

(polyurethane) spray applied to the underside of sarking boarding to form an insulating layer.

Ventilation v “sealed” roof: with the introduction of vapour permeable membranes, roof can now be

constructed without ventilation at eaves and ridge, i.e. relying on the natural vapour diffusion through

the membrane to dissipate any moisture in the roof space. Although most systems have Agreement

certification care needs to be taken when specifying, particularly where the roof encloses kitchens or

bathroom.

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