1 Thermal and Moisture Protection
2 Major Topics Moisture Control Waterproofing Membrane Clay Cementitious Dampproofing Hot-applied Cold-applied
3 Major Topics con’t Building Insulation Rigid Mineral Fiber Loose-fill Foamed-in-place Roofing Low vs. steep slope Types of roofing materials
4 Major Topics con’t Flashing Siding Sealants
5 Moisture Control Moisture is NOT damaging to construction in its vapor form…the problems arise as it Condenses (liquefies) Freezes (solidifies) These may cause organic materials to decay, metals to corrode, paint coatings to blister, and in the case of freezing, may cause concrete and masonry to crack.
6 Key Moisture Absorption Considerations Dimensional instability – the changes in moisture can cause a change in material dimensions (ex: wood drying) Deterioration – causes physical, chemical, and biological breakdown of materials (ex: steel rusting) Condensation tolerance – varies for each material Effect on heat flow – if material contains moisture it can increase the conductivity
7 Permeability Permeance – measure of water vapor’s flow through a material of specific thickness or an assembly of several materials Metals & glass – very low permeability Materials with a permeance of 0-1 are considered vapor retarders See Figure on page 431 for examples of various materials and their permeance
8 Moisture Condensation Moisture condensation in walls, floors, and roof and ceiling assemblies can be controlled by: Providing a vapor retarder on the interior side of the assembly which limits vapor entering the structure Provide adequate ventilation for the structure in spaces such as attic areas and crawl spaces
9 Waterproofing As defined in ASTM D1079: “the treatment of a surface or a structure to prevent the passage of water under hydrostatic pressure.”
10 Membrane Fluid-applied membranes are usually: Polyurethane Hot Rubberized Asphalt – not as elastic as polyurethane and requires a thicker coat
11 Sheet Membranes Butyl synthetic rubber sheet [60 mils thick] Ethylene propylene diene monomers (EPDM) [min. 1/16” thick] Pre-molded bituminous [7 ply] Rubberized asphalt [56 mils] Self-adhesive butyl [60 mils- requires adhesive primer]
12 Bituminous Usually applied on vertical below- grade surfaces Hot coal-tar pitch or hot asphalt The number of plies, overall thickness, and content vary according to the depth of the hydrostatic head (in ft. – all increase as the depth increases)
13 Clay waterproofing Bentonite clay – when wet, it expands to between 10 to 15 times its dry volume. It is typically mixed with water & sprayed in place (also available in dry sheets between cardboard) Placed below grade to exterior surfaces
14 Cementitious Waterproofing Composed of portland cement, aggregate, and an acrylic or plastic admix. It may also contain iron fillers (then known as iron oxide waterproofing) Hydraulic cement – another form of cementitious waterproofing used to seal holes, cracks and open joints (often in free-flowing water)
15 Dampproofing May be hot- or cold- applied Hot consists of an asphalt primer or a coal-tar-based primer Used on the exterior of buildings- not interior because of lingering odor and the problems associated with using “hot” products indoors.
16 Building Insulation Usually added to the roof, walls, and floors of a structure 4 basic classifications are: Rigid board Mineral fiber Loose fill Foamed-in-place Listed according to their R-Values
17 Rigid Insulation Usable in all parts of a building –usually in a board form Most are [Resistance/inch]: Polystyrene – sensitive to daylight, give off carbon monoxide while burning Polyurethane [6.25] – may expand after exposure to moisture Polyisocyanurate [7.2] Perlite [2.78] – will not burn, tends to absorb water Phenolic [8.3] –breaks easily, corrodes metal Cellular glass block- [2.5] – breaks easily, deteriorates if exposed to freezing & thawing Organic fiber – roofing systems primary use, wood fibers and water resistant binders Glass fiber Composites – take advantage of high R-values of some materials in combination with the stability of others
18 Mineral Fiber Insulation Products made from fibers from rock, slag, or glass Naturally resistant to fire, moisture, and vermin May be semi-rigid boards, batts, or blankets (longer than batts and sold in large rolls). Intended to fit between studs (16” or 24” o.c.)
19 Loose-fill Insulation Comprised of fibers, granules, or chips May be poured or “blown” into attics or wall cavities Common additives may include: adhesives, and chemical treatments to resist fire and vermin
20 Foamed-in-place Insulation Created by a chemical reaction that expands a mixture of components as much as 30 times Curing typically takes from hours, at which time the mixture solidifies into a cellular plastic Care must be taken not to “overfill” a cavity
21 Roofing Low slope – in general, these are roofs which slope less than 41/2”/ft. On low slope roofs a system of compatible components is selected to work together to form a waterproof membrane Common systems used are: built- up roof or single-ply
22 Examples of Single-Ply Membranes EPDM – [ethylene propylene diene monomer] factory cured elastomer, bonded to themselves using adhesives CSPE (DuPont Hypalon) –synthetic rubber, may also be liquid CPE – un-reinforced or polyester reinforced sheet material PIB – formulated from isobutylene and other polymers, carbon black, and additional additives
23 Example of Built-up Roof
24 Steep Roofing Slopes exceed 41/2”/ft. Many materials used in modern roofing practices existed centuries ago (clay tiles, and stone) Material used is based on: cost criteria, slope of roof, expected service life, wind resistance, fire resistance, and local climate.
25 Roofing Material and Slope Min. Slope Type of roof 2 in 12Asphalt shingles (warranty may require a steeper slope - 4 in 12) 3 in 12Mineral fiber-cement shingles, wood shakes or shingles 4 in 12Slate shingles, concrete tile (other than flat) 5 in 12Flat clay tile, concrete tile
26 Roofing Underlayment Should be asphalt-saturated felt (usually a No. 15 or No. 30 used, may require more than 1 layer- depending on roofing material selected) –see pg 463, fig Applied immediately after the roof sheathing is in place
27 Underlayment Performs These Functions: Protects sheathing from moisture absorption Prevents the entrance of wind- driven rain onto sheathing Prevents direct contact between asphalt shingles and resinous areas in wood sheathing (chemically incompatible-may damage shingles)
28 Types of Roofing Materials Asphalt shingles Slate Tile Mineral-Fiber-Cement shingles Wood shingles and shakes Metal
29 Roofing Styles
30 Examples
31 Examples
32 Examples of Roofing
33 Comparison of Types of Roofing
34 Flashing Should be installed at all intersections of other roofs, walls, and projections from roof. Flashing should be made of corrosion resistant materials such as: Galvanized or stainless steel (min 26 gauge) Aluminum (0.019 inch min.) –avoid using next to masonry Copper (16 oz.) –if not lead coated…may stain surrounding materials Flexible sheet- made of PVC or modified polymers- used in single-ply & some BUR [built up roof]
35 Typical Locations for Flashing Valleys –joint formed by 2 sloping roofs Chimney Eaves – ice forming along the eaves Drip edge All roof penetrations
36 Siding The type of wall siding selected depends on cost, expected life service, wind resistance, fire resistance, local climate, and maintenance. Possible materials include: Mineral-Fiber-Cement shingles Wood shingles & shakes Aluminum and Vinyl siding Wood or Hardboard siding Bevel, Tongue & Groove, Lap, Board and Batten (see pages for examples of these)
37 Sealants Basic types of building sealants include: Elastomeric (rubber like) –polysulfides, silicone, polyurethane [expansion joints] Solvent release curing [small-joints (3/16” or less] Latex emulsion [small interior joints, doors,windows] Tape [glazing, concealing lap joints] Acoustical [seal sound transmission, electrical outlets] Preformed Foam Oil-based caulking compounds [doors, windows, masonry subject to little or no movement]
38 References Construction Materials and Processes, 3 rd Edition. Watson, Don A.. McGraw-Hill, Imprint ISBN: Construction Principles, Materials, and Methods, Seventh Edition. H. Leslie Simmons, John Wiley and Sons, Inc., Olin’s Construction Principles, Materials, and Methods, Eighth Edition. H. Leslie Simmons, John Wiley and Sons, Inc., 2007 Architectural Materials for Construction, Rosen, Harold J. and Heineman, Tom. McGraw-Hill, ISBN: Basic Construction Materials, 6 th Edition. Marotta, Theodore W. Prentice Hall, ISBN: X Building Construction: Materials and Types of Construction, 6 th Edition, Ellison, Donald C., Huntington, W.C., Mickadeit, Robert E.. John Wiley & Sons. ISBN: Architectural Graphic Standards: Student Edition, Abridgment of 9 th Edition. The American Institute of Architects. John Wiley & Sons. ISBN: