Thermal and Moisture Protection

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 7.1-7 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 24-72 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

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 7.6-6 • 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 http://www.tricityroofing.com/types.html

33. Comparison of Types of Roofing http://aihomeinspection.com/exterior.html

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 519-522 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, 3rd Edition. Watson, Don A.. McGraw-Hill, 1986. Imprint 2000. ISBN: 0-07-068476-6 • Construction Principles, Materials, and Methods, Seventh Edition. H. Leslie Simmons, John Wiley and Sons, Inc., 2001. • 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, 1996. ISBN: 0-07-053741-0 • Basic Construction Materials, 6th Edition. Marotta, Theodore W. Prentice Hall, 2002. ISBN: 0-13-089625-X • Building Construction: Materials and Types of Construction, 6th Edition,Ellison, Donald C., Huntington, W.C., Mickadeit, Robert E.. John Wiley & Sons. ISBN: 0-13-090952-1. • Architectural Graphic Standards: Student Edition, Abridgment of 9th Edition. The American Institute of Architects. John Wiley & Sons. ISBN: 0-471-34817-1