Moisture Protection and Thermal Insulation Flashcards
Admixtures
mixtures added to conrete mix to make it water repellent
- materials such as salts of fatty acids, mineral oil, and powdered iron
- reduce strength of concrete, but make it less permeable to water
bituminous coatings
asphalt or coal-tar pitch materials applied to the exterior side of the foundation wall
-brished or sprayed on, not or cold
cementitous coatings
- portland cement mortar troweled on masonry or concrete foundation walls
- mostar coatings are used on rough surfaces to make them smooth
membrane
- built up layers of hot or cold applied asphalt felts or membranes of butyl, polyvinyl chloride, and other synthetic materials
- usually used for waterproofing walls subject to hydrostatic pressure
plastics
made of silicone and polyurethane coatings
-reserved for above grade damping
dampproofing
control of moister that is not under hydrostatic pressure
waterproofing
control of moisture under hydrostatic pressure
bentonite panels
flat packages of bentonite panels inside kraft paper packages
- placed under slabs and against walls
- after backfilling the clay expands in the presence of moisture to form a waterproof barrier
Longterm Thermal Resistance (LTTR)
thermal resistnace value of a closed cell foam insulation product measured after storage for five years under prescribed laboratory conditions
Loose fill
- Glass wool/ rock wool
- all loose fill require vapor barrier or vapor retarder
- Fill is blown onto attic floors and into wall cavities through holes drilled in siding
- Good for retrofit insulation in older building, may settle in walls
cellulose insulation
shredded wastepaper or wood fibers
- contains 75% recycled matrials
- combustible but chemicals are added to make it fire resistant
fiberglass loose fill
insulation is made by spinning molten glass into fibers
-contains 20-30% recycled materials
vermiculite
- hydrated laminar magnesium aluminum ironsilicate
- may contain asbestos
Batt or Blanket
- Glass wool/ rock wool
- Between framing members and held in place by friction or facing stapled to framing
Rigid Board
Polystyrene Foam Boards are applied over wall framing members either as sheathing on the exterior or as a layer beneath the interior finish material
High R value, can be used in contact with the earth, moderate cost
Foamed in place
Polyurethane
Foam is mixed from two components and sprayed or injected into place where it adheres
High R value, high cost, good for structures that are hard to conventionally insulate; conforms to shape of cavity; seals all cracks
reflective insulation
whan a radiant barrier is combined with a backinf of insulation
where should a radiant barrier be placed to block heat gain?
to block heat gain, a radiant barrier is placed on the outside of conventional thermal insulation, such as on top of attic insulation
-heat radiated from the hot roof deck is reflected back toward the roof, reducing the heat that would normally strike the top of the thermal inslation
refective surfaces have two properties that make them good for insulation
-reflectivity: measure of how much radiant heat heat is reflected by the material; measure between 0-1; material with a reflectivity of 0.8 means that 80% of the radiant energy striking the material is reflected
–emissivity: measure of how much energy is emitted; energy given off as a result of surface temperature
to be effective radiant barrier must have amonimum reflectivity of ___ and emissivity of ___
reflectivity - 0.9
emissivity - 0.1
insulated concrete form (ICF)
- interlocking foam insulation blocks or panels that serve as forms for pouring concrete walls
- ICF remain in place while concrete cures
- serves as backing for gypsum board
- foam used is usuallu expanded polystyrene (XEPS)
Approximate R values for SIPs range from
When describing size, estimating, and ordering materials, roofing area area is referred to in …
…squares. A square is equal to 100 square feet
Shingle Exposure
shingles are laid so that only a certain portion of each shingle is visible: this is caled exposure
- this dimension varies with the pitch of the roof
- 30 lbm asphalt felt is used as an underlayment
Slate tile
- made by splitting quarried slate into rectangular pieces from 6 in to 14 in wide and from 16 in to 24 in long
- about 1/4” thick
- laid over 30 lbm asphalt roofing felt
- very expensive but very durble and fire resitant ; can last over 100 years
clay tile
simalr to slate tile in roof buildup
-also expensive bu durable and fire resistant
concrete tile roofing
less expensive than clay tile
also very durable and fire resistant
metal roofing
- durable, attractive, can conform to a wide varaity of roof shapes
- high cost and difficult to installe properly due to a high coefficient of expansion
- joints must be design to account for expansion and contraction
- materials include copper, galvinazed iron, aluminum, and terneplatem stainless steel
- installed over asphalt roofing felt laid on top of wood or nailable concrete decking; exception to nuderlayment is for terne or tin roofs, which require a rosin-sized paper because asphalt can react with the tin
terneplate
steel sheet coated with lead and tin
minimum slope for metal roof
3:12
roof components
Horizontally applied board sidings are nailed so that the nails pass through the
sheathing and into the studs
• Allows for installation over insulating sheathing materials without requiring a nail
based sheathing
• In the US, boards are nailed tightly over the wall sheathing and housewrap
• In Europe, siding is nailed to vertical wood spacers (1x3’s) that are aligned over
the studs…called a rainscreen and creates a pressure equalization chamber
behind the siding that acts to prevent water penetration in a wind drive rain
preformed roof panels
- shaped mpieces of metal or assemblies of metal with insulation between that are self supporting an apn intermediate supports
- roof panels span purlins, and wall panels span horizontal girts
- corrugated or fluted sheets
- made from aluminum, galvanized steel, and porcelain enamel steel
- most economical when used on large, flat, unbroken expanses of walls and roofs
Membrane roofing
- includes materials applied in thin sheets to nearly flat roofs
- includes liquid applied products that can b applied to any roof slope