felt vs “ASTM 30# asphalt felt” (ASTM D-266) - Green Building …
WEBSep 11, 2009 · ASTM standards refer to #30 felt as Type 2. The lightest unrated #30 asphalt felt is still heavier than the heaviest ASTM-rated #15 felt, making it a logical choice for concerned builders. "Asphalt felt has a permeance of only 5 perms when dry, but a much higher rating of 60 perms when wet.
Cedar shakes, unvented attic, SPF – underlayment alternatives
WEBFor eaves, two courses of 36” wide I&W with minimum 3.5” side laps and 6 inch end laps. · Benjamin Obdyke Cedar Breather. · Certi-Sawn Western Red Cedar Tapersawn Shakes – 7/8” butt x 18”. o 5-1/2” exposure. o Install using stainless steel type 316 nails. · Valleys to be closed and woven with concealed red copper flashing.
To use Tyvek or not? - GreenBuildingAdvisor
WEBJan 2, 2011 · But, if I used sheathing (preferably sawn lumber boards for breatheability and durabiity), then I always prefer #15 felt, and preferably ASTM D226 #15 felt (11.5 – 12.5 lbs per square). Most building supply houses seem to stock ASTM D4869 #15 felt (8.0 – 9.7 lbs per square), while unrated #15 felt might be only 7.6 – 8.8 lbs per square.
Cedar shingles directly over rigid - GreenBuildingAdvisor
WEBThe small-diameter fasteners required for cedar shingles would tend to be unstable if not embedded directly into wood sheathing (plywood or strapping, if not sawn boards). #15 felt is the appropriate underlayment for cedar shingles, which swell and shrink with changes in ambient relative humidity and rainfall.
Building felt vs. house wrap – white cedar sidewall
WEBFeb 9, 2010 · Unrated felt can vary from 7.6 – 8.8 lbs/square saturated weight. ASTM D4869 #15 felt can be 8.0 – 9.7 lbs/square. And ASTM D226 #15 felt must be 11.5 – 12.5 lbs/square (which is the code standard for WRBs). Asphalt-saturated rag felt has proven itself effective as a weather barrier since 1844.
Need wall construction in Northern California advice
WEBNov 12, 2010 · 3. drywall (air barrier) - "final blower door test after drywall and insulation are complete but before window and door and baseboard trim." 4. 2*6 wall with dense packed blow in borate treated cellulose (at least 3 lbs. per cubic foot -- 3.5 pounds is better -- to minimize settling) 5. no added formaldehyde plywood.
Understanding R-Value - GreenBuildingAdvisor
WEBMar 24, 2009 · R-value measures heat transfer by conduction, convection, and radiation. Measuring a material’s R-value according to the ASTM C518 test procedure requires a heat flow meter like this German appliance manufactured by Netzsch-Gerätebau. After a sample is placed between a hot plate and a cold plate inside the calibrated testing apparatus, the ...
Kingspan Kooltherm Phenolic Foam Rigid Insulation
WEBJan 25, 2018 · Kooltherm is a type of rigid foam called phenolic foam.) [Editor’s note: Phenolic foam rigid insulation was introduced in the U.S. in the 1980s and sold by Beazer East and Johns Manville. Serious corrosion problems of fasteners and steel decks that were in contact with the foam resulted in legal action, and both companies ceased production …
Foamglas – My New Favorite Insulation Material
WEBSep 7, 2010 · Foamglas is a cellular glass insulation material that’s impervious to moisture, totally inert (no offgassing), resistant to insects and vermin, strong, and reasonably well-insulating (R-3.44 per inch). It can be used for insulating roofs, walls, and below-grade applications, including beneath slabs. It is produced in 18″ x 24″ dimensions ...
Cold-Weather Performance of Polyisocyanurate
WEBSep 4, 2015 · By Martin Holladay | September 4, 2015. It's R-6 per inch during the summer, but only R-4.5 per inch on a cold day in winter. The insulating performance of polyisocyanurate insulation is significantly degraded at cold temperatures. Image Credit: Marc Rosenbaum. The ability of insulation products to resist the flow of heat changes …