WebJan 3, 2024 · You can use flash and batt without exterior continuous insulation since the sheathing and framing can dry to the exterior (with proper WRB and cladding choices). The main drawbacks are: spray foam is expensive, usually more damaging to the environment and largely bad economics thanks to thermal bridging from framing losses. WebApr 9, 2024 · Dana turned me onto the idea of flash and batt for our completely uninsulated walk-up attic in our 1910 duplex, and after many months of comparison shopping of foam installers, a re-visit after not-great application, two pallets delivered of rock wool, and many many hours of trimming batts (very few bays were a standard size for either 16 on center …

Flash and Batt in the Roof - GreenBuildingAdvisor

WebNov 15, 2014 · Thermal Control. Installed insulation R-value: The installed R-value is approximately R-12 for two inches of high density spray foam (2.0 pcf) and R-13 for three and a half inches of fiberglass batt, totaling R-25. … WebFeb 10, 2011 · Flash and Batt Technique for Wall Stud Cavities Combining insulation options in the same cavity results in better yet more affordable thermal performance. piri \\u0026 tommy villiers

Flash & Batt Condensation Issue - GreenBuildingAdvisor

WebFlash and batt Fiberglass-batt insulation Although inexpensive and widely available, its thermal performance is easily and seriously defeated by even small air leaks. This foam is a better insulator, and it blocks the passage of both water vapor and air. WebMay 29, 2011 · First of all, open-cell foam cannot be used in a flash-and-batt or flash-and-cellulose job, because a thin (1 to 2 in.) layer of open-cell foam is not an air barrier. If you are installing a thin (1 to 2 in.) layer of spray foam as an air barrier, it has to be closed-cell foam, not open-cell foam. 2. WebThe flash-and-batt (or flash-and-fill) approach combines a layer of closed-cell spray foam with a layer of fluffy insulation (fiberglass, mineral wool, or cellulose). The illustration … hajen lomma