division 7.pdfx

DIVISION 07:THERMAL AND MOISTURE PROTECTION

Moisture Protection

Most building materials are subject to some degradation by exposure to moisture. Building systems must be designed to resist the transfer of moisture to the inside of the structure.

Moisture comes in several forms

Liquid Vapor Ice

Moisture comes in several forms

WATERPROOFING/ DAMPPROOFING

Waterproofing

Waterproofing is the application of a material to prevent the transfer of moisture in liquid form to the inside of a structure in the presence of hydrostatic pressure.

Dampproofing

Dampproofing is the application of a material to reduce the likelihood of moisture transfer to the inside of a structure.

Dampproofing assumes no hydrostatic pressure is “pushing” the moisture toward the building.

1. WATERPROOFING AND DAMPPROOFING

A mortar or concrete is considered impermeable when it does not permit passage or flow of water through its pores or voids.

The absorption of a mortar or concrete is the property of drawing in or engrossing water into its pores or voids by capillary action or otherwise.

If the pores or voids between particles are sufficiently large and connected from surface to surface of the wall, the concrete will be permeable to water.

If the pores or voids are very minute, but connect with one another, theoretically they may act as capillary tubes, but the capillary forces will tend to hold the water and prevent the passage of water.

1.01 WATERPROOFING OF CONCRETE

a. Impermeability through a Dense Concrete Accurate grading and proportioning of the concrete materials in order to secure a concrete so dense as to be waterproof.

b. Waterproofing Coatings and Washes Applying waterproof coatings or washes to the concrete after it is in place.

c. Integral Waterproofing CompoundsMixing foreign substances with the concrete.

d. Membrane WaterproofingSurrounding the concrete with layers of waterproofing materials.


The various methods of waterproofing concrete may be classified as follows :


a. Impermeability through a Dense Concrete



Portland cement mortar and concrete can be made practically waterproof or impermeable without the use of any integral waterproofing materials; but in order to obtain such impermeable concrete or mortar considerable care should be exercised in selecting good materials :

• Well-graded sands containing considerable graded fine material are preferable for making impermeable concrete, or fine material in the form of hydrated lime, finely ground clay, or an additional quantity of cement will be of value.

• The consistency of the concrete mixture should be wet enough so that it can be puddled, mixture should be well spaded against the forms to avoid the formation of pockets on the surface.

• Care should be taken not to over trowel which may cause erasing the coating will be effective.

• Defective workmanship, resulting from improper proportioning, lack of thorough mixing, separation of the coarse aggregate from fine aggregate in transporting and placing the mixed concrete, lack of density through insufficient tamping or spading, improper bonding of work joints .

• The use of imperfectly sized and graded aggregates.

• The use of excessive water, causing shrinkage cracks and formation of laitance-seams .

• The lack of proper provision to take care of expansion and contraction, causing subsequent cracking .



Permeable concrete results from :

Alum and soap mixtures applied in alternate mixtures (known as the Sylvester process), which penetrates the pores of the concrete forming insoluble compounds due to chemical action between the alum and soap solutions, and these compounds prevent percolation.

- use in proportions of ¾ gal. of soap to 1 gal. of water, and 2oz. of alum to 1 gal. of water, both substances to be perfectly dissolved in water before using.

- should be applied with a soft, flat brush (one for each solution), the soap boiling hot and the alum solution at 60 to 70F.



b. Waterproofing Coatings and Washes

The materials employed as surface coatings may be classified as follows :

Alum, lye and cement washes .

Cement grout, with or without the addition of water-repellants.




Paraffin and other mineral bases, applied cold in solution or prepared in melted.

Miscellaneous materials of unknown composition sold under various trade names.

What's the Difference: Epoxy vs. cement grout

Portland-cement grout is cheap and easy to work withSold as a dry mixture, cement-based grout is suitable for most applications. It’s readily available in a variety of colors and is more forgiving to work with than epoxy grout. Unlike epoxy

grout, its residue can be buffed off tile the day after it’s applied. However, epoxy-grout ingredients are packaged to ensure

accurate mixing. Cement grout can be mixed incorrectly if too much or too little water is added, possibly weakening the grout

while also causing color to fade or to be inconsistent. Also, cement-grouted joints require grout sealer, but epoxy-grouted

joints don’t.

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Epoxy grout is expensive but more durableEpoxy grout has several appealing qualities, including its strength, its stain- and chemical-resistance, and its availability in a broad range of colors. These qualities make it the best choice for heavily trafficked locations or in areas that often come in contact with powerful cleaning agents.Epoxy grout is applied the same way as cement grout. It’s spread over tile with a float and packed into the grout joints. Excess grout is then removed. Although this technique is the same for both types of grout, the stress level is much higher when working with epoxy. This is because epoxy has a shorter working time than cement, especially in warmer temperatures. Also, hardened epoxy is hard to remove, so it’s crucial to remove residue completely. Any epoxy left on the tile surface for an extended length of time will likely become a permanent feature.Another epoxy-grout shortcoming is the possibility of its color darkening or yellowing under exposure to the sun, although that is less likely to occur with new epoxy-grout formulas.

Specially prepared bituminous products, e.g., “FLINT-KOTE”, “JOHN-MANSVILLE”, etc




Asphalt emulsions - Generally called Asphalt Base Clay Emulsions, minute asphalt particles dispersed in water and maintained in suspension (until applied) by a mineral colloid emulsifying agent. When the water vehicle evaporates, resilient reinforced weatherproof film remains which resist the passage of free water but allows movement of water vapor through the film and are classed as breathing films.

Cutback Asphalts - composed of a variety of products from thin liquids to heavy paste, often one or more asphalts dissolved in solvent are filled with minerals and fibers to meet requirements of different coating uses and provide tough, durable films resistant to the passage of water vapor.

c. Integral Waterproofing Compounds

These are manufactured and sold under various trade names, and are available in powder or liquid form, e.g.:



“SAHARA”“POZOLITH”“AQUELLA”Truscon “ZILICON”“ANTI-HYDRO”

The addition of the integral waterproofing compounds will not, however, compensate for lean mixtures, nor for poor materials, nor for poor workmanship in the fabrication of concrete

d. Membrane Waterproofing

Layers of waterproofing materials used in this method range from ordinary tar paper laid with coal-tar pitch to asbestos or asphalted felt laid in asphalt.



Thermal Protection

• Critical for building to provide comfortable spaces for occupants.

• Owners and designers must also consider the overall impact of their designs on the environment and how a building consumes energy.

a. Sheet Metal Roofing

2.01 TYPES OF ROOFING

2. PREFORMED ROOFING

• Galvanized Iron Roofing – various corrugations and rib sections.

• Aluminum Roofing – various corrugation and rib sections

b. Plastic Roofing• Plastic – various corrugation and rib sections• Polycarbonate – corrugated and flat sheets

c. Tile Roofing

• Clay• Concrete

d. Shingles

• Wood• Tar

Metal (steel, aluminum, tile and copper): Metal roofs are some of the coolest roofs around, both in temperature and style for new homes. Metal roofs are available in copper, aluminum, and stainless steel, and often have a high percentage of recycled content. They offer high insulation solar reflectance, and durability, often lasting twice as long as wood or asphalt. Metal shingles typically simulate traditional roof coverings, such as wood shakes, shingles, slate and tile. Aside from its longevity, metal shingles are much lighter than most materials and very resistance to adverse weather.

A. SHEET METAL ROOFING

House Style: Bungalow, ranch, contemporary, cottageLife Span: At least 50 yearsGreen Factor: Very green because they are highly energy-efficient and environmentally friendly




• Galvanized Iron Roofing

Corrugated galvanized iron sheets are manufactured in lengths of 5 to 12 ft. in 1 ft. increments, the 8 ft length being the most commonly used.

Width of sheets is 32”. Each sheet has 10 corrugations with a pitch of 3”.

For roofing, Ga. 26 is generally specified, Ga. 24 is preferred.

Galvanized iron sheets are also sometimes used as siding for industrial buildings. When used as siding, courses shall be lapped at least 6”.




• Aluminum Roofing Corrugated aluminum is rigidized sheet

fabricated of special aluminum alloys specifically developed for this purpose.

Has a high insulating value and is about one-sixth lighter than similar materials.

Is silvery in color, strong and does not stain adjoining materials.

It reacts, however, with dissimilar materials, lead-base paints green or damp wood, certain wood preservatives, lime mortar, concrete, and other masonry materials and must be insulated from contact with these materials .

Width of sheets are 32-5/8”, 32”, 31-1/2”, 31-1/8”, and 30-5/8”; lengths are from 6 to 12 ft. in 1 ft. increments. Number of corrugations for 32” sheets and wider is 12; sheets of narrower width have 10 corrugations.

Standing Seam Metal

Standing seam is one of the most popular metal roofing systems because of its beauty, durability, longevity, simplicity, versatility, and bold looks. Homeowners considering installing standing seam on their property, often do so because they like the modern style of raised seams giving their home that bold, contemporary look and feel, along with unmatched durability, longevity, and energy efficiency.

Residential standing seam panels are generally 12 to 19 inches wide. They are typically made out of painted galvanized steel/G-90 Steel (zinc-coated steel), galvalume steel (zinc and aluminum alloy coated steel) offers better protection from corrosion than galvanized steel), or pre-painted aluminum.

Two Types of Standing Seam:

A field-locked (mechanically locked) standing seam requires special crimping tools to crimp down/lock the seams during the installation.

A snap lock standing seam system is a bit pricier, but the seams can be locked by a simple snapping of the panels together.

METAL TILE SHEETSSteel tile is an elegant and durable roof covering suitable for all types of steep roofs. Combining traditional and modern solutions it is used for raising houses, outbuildings, sacral buildings and for renovation of old roofs.Steel tile is profiled out of sheets coated with zinc on both sides and covered with several layers of varnish, which guarantees longevity. It is one of the lightest roof materials, which is a big advantage, as it does not require the use of heavy roof truss structure. The weight of materials is very significant in the case of old roof renovation, because after changing the tiles to light steel tiles the roof structure does not need strengthening. One square meter of steel tile roofing weighs about 4,7 kg, which makes it almost 10 times lighter than traditional ceramic tiles.

Steel Tile is unique in providing full-length custom-cut panels up to 30 feet in length. There are several advantages to using a Steel Tile metal roofing system, including minimal on-site preparation, faster installation per square foot, resulting in time and cost savings. Fewer horizontal seams reduce the possibility of leaks unlike smaller multi paneled clip-on roofing systems. Steel Tile metal roofing panels weigh less than half the weight of traditional shingles per sq.ft and in many cases the panels can be applied directly over the old shingles, saving removal and dumping fees.

METAL TILE SHEETS

STAINLESS STEEL ROOF

COPPER ROOFS

Copper roofs offer corrosion resistance, durability, long life, low maintenance, radio frequency shielding, lightning protection, and sustainability benefits. Copper roofs are often one of the most architecturally distinguishable features of prominent buildings, including churches, government buildings, and universities.] Today, copper is used in roofing systems, flashings and copings, rain gutters and downspouts, domes, spires, vaults, and various other architectural design elements. At the Lyle Center for Regenerative Studies copper is used for regenerative principles of sustainable design: if the building were to be dismantled the copper could be reused because of its high value in recycling and its variety of potential uses. A vented copper roof assembly at Oak Ridge National Laboratories(U.S.) substantially reduced heat gain versus stone-coated steel shingle (SR246E90) or asphalt shingle (SR093E89), resulting in lower energy costs.[

b. Plastic Roofing



• Corrugated or Ribbed Roofing

Corrugated sheets are manufactured in in same widths and lengths as Metal Sheet Roofing.

Metal reinforced plastic roofing is available. Ideally used in sites of high salinity levels.

• Sheet Roofing

Polycarbonate Sheets. Ideally used in greenhouses, patios, outdoor

sheds, and skylights.

c. Tile Roofing



• Clay Tiles

• Concrete Tiles

c. Tile Roofing



• Clay Tiles

CLAY & CONCRETE TILES

Clay & Concrete Tiles: Clay tiles are very heavy, requiring additional roof framing, but they are non-combustible and extremely durable. Clay roofing tiles can come in lighter colors, which adhere to the cool roof standards and can reflect well over 50% of the sun's solar energy. Concrete roofing tiles offer elegant, enduring aesthetics for your home's design and added value. Concrete tiles are very versatile and provide greater protection to the homeowner. These flexible tiles come in so many different hues, shapes, textures and styles that they don't even look like tiles at all. Shingle, shake and slate are just some of the varieties of tile.

House Style: Mediterranean, European, Mission and some contemporary or ranch-style homesGreen Factor: If a local source is available, clay tiles are definitely one of the greenest roofing choices. Concrete is highly energy-efficient and can be made from a sustainable mixture

d. Shingles



• Wood Shingles• Tar/Asphalt Shingles

WOOD SHINGLES AND SHAKES

Wood shingles and shakes: Wood shingles and shakes can be purchased in cedar, redwood, southern pine and other woods, cedar being the most costly. Wood shingles are cut by machine, while wood shakes are handmade and have a rougher look. Since most wood shingles and shakes only have Class C fire ratings or no ratings at all, be sure to check your local building codes before deciding on this type of roofing. You can purchase Class A wood shingles with fire-resistant treatment for an additional cost.

House Style: Ranch, cottage, bungalows, cottage, historic and contemporaryGreen Factor: A natural product, but very high maintenance, poor fire rating and they tend to rot, split and mold.

Asphalt shingles: Over 75% of American roofs have asphalt shingles due to low cost, ease of installation, and resiliency. Unfortunately, asphalt shingles have a low insulative value and a shorter lifespan than many other roofing materials available today. They are also made from petroleum products and are not usually recyclable because of the layer of fiberglass added to the shingles. Standard asphalt shingles come in a variety of colors, longevity options, and price points and are always going to be your cheapest option for your roof, but they have the worst environmental track record.

ASPHALT SHINGLES

House Style: Can be used for any architectural styleLife Span: 15 to 30 years Green Factor: Least-green roofing option

is a black substance available in solid, semi-solid, or liquid states at normal temperatures.

composed of mixed indeterminate hydrocarbons, appreciably soluble only in carbon disulfide or other volatile liquid hydrocarbon.

used for sealing built-up roofing, and joints and cracks of concrete pavements.

a. Bituminuous Cement

3.01 TYPES OF JOINT SEALANTS

3. JOINT SEALANTS

b. Silicone Sealant

3.01 TYPES OF JOINT SEALANTS

3. JOINT SEALANTS

End of Div 07 THERMAL AND

MOISTURE PROTECTION

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