Recent Q&A

• Is a vapor open membrane needed below a ventilated attic?

  I am building a passive house in NH climate zone 6A with thick EPS exterior insulation, where the WRB/Air barrier will be between the foam and the sheathing. The WRB…

• Sloped perimeter insulation for drainage plane at bottom plate/wall intersection in persist wall

  I am in the process of designing a wall with thick exterior rigid insulation with "innie" windows and the drainage plane at the sheathing behind the foam.The one area that…

• Attaching/flashing a gable end screened in porch to a house with thick exterior rigid insulation

  I am building a 24 on center 2x6 house that sits on a frost protected raft slab made by legalett and I could use some advice with what to do.…

• Secondary air barrier at attic – ventilated roof deck vs ventilated attic

  In climate zone 6I have seen many articles referencing the goal of many builders to add a secondary air barrier/wind-tight layer, but often those details end at the walls, especially…

• Thermal performance of steel embedded in foam

  The company Legalett out of Canada offers an EPS panel system (Thermalwall) designed to make installing thick exterior foam both easier and with less thermal bridging at screw heads. Its…

• Thermal bridging of I-joist walls

  Has anyone seen any efficiency modeling data that shows the thermal performance differences due to thermal bridging in a I-joist, wall versus either a double wall or a Larsen truss?…

• Membrane air leakage due to strapping nails

  I know that many experts recommend putting an interior airtight membrane such as Siga Majrex behind strapping and or a service cavity to prevent accidental air leakage, but has anyone…

• Where to put concrete perimeter insulation on a double wall assembly to avoid thermal bridging

  Hi Everyone,I am planning to build a slab on grade energy efficient home in NH, climate zone 6. I am aiming for a whole wall assembly R-Value of between R-40…

• Help with my high energy bills for new efficient home

  -Edit- Turns out the heat pumps needed fine tuning. The contractor did not tighten line sets enough when installed so the units lost refrigerant. Additionally I had the contractor set…

• ERV installation

  嗨,我正在寻找一些建议ing the use of flex duct vs rigid duct in my ERV installation. All of the literature I have read seems to…