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1 Answer

Spray foam over XPS on external wall

I purchased about 600 bdf of spray foam, and had planned on using it for my rim joists of my baasement (about 200 board foot of it). My house is a walk-out, so I have a combination of poured concrete walls and above-grade 2x6 stud-framed wall in the basement level.

I have sheets of 1" XPS available, so I was thinking about layering the XPS rigid foam sheets on my 2x6 walls, at 2" thick (possibly 3") and then covering that with a 1" layer of spray foam to air-seal it.

Asked By Jeff M | Oct 22 14
4 Answers

How does the attic fan work? And can you use it in the winter?

We bought a house early this year in northern Virginia that has a attic whole house fan. It h's a pulley on it that closes a box on the fan or opens it. we believe that one way makes the air blow in the attic and the other to push the air down into the closet under the stairs to the bottom level of our home. We had it where the air vented to the attic all summer but not sure that we did it correctly. Now it is getting cold and we are using the fireplace and not sure if we should run the fan or not. The fan is attached to a thermostats in order to adjust it.

Asked By Aleasha Jeffries | Oct 22 14
3 Answers

Double wythe CMU vs. Thermomass

After living in Europe for several years I have become a fan of concrete. I build in the Southeast and have mainly used concrete commercially and as stem/foundation/retaining walls and for slabs in residential.

Asked By leo kloop | Oct 22 14
1 Answer

attic insulation existing

I have a 1800 sq ft ranch home built in 1969. climate zone 5. existing attic floor/ceiling area has a layer of 3" fiberglass insulation with vapor retarder facing the heated space. the second layer of insulation is a 3" layer of fiberglass with vapor retarder facing the attic area. both layers have been installed inside the joist bays and stuffed very tightly at the top of wall/ceiling intersection-no soffit vents in place. the roof has box vents and gable vents in place for ventilation.

Asked By bob prince | Oct 22 14
7 Answers

Closed-cell spray foam versus dense-packed cellulose - Noise control in a PassivHaus

This is a comment rather than a question.

In our pre-certified PassivHaus in northern NJ, we have 10-inches of densepack cellulose and 2-inches EPS in the walls, and 10-inches of closed-cell spray foam in the roof.

We've noticed that the noise attenuation through the walls is much greater than through the roof.

Most of the noise getting into the attic comes through the roof, which is asphalt shingle over plywood decking on 2x12 rafters, with the space between the rafters filled with 10-inches of the closed-cell spray foam.

Asked By Len Moskowitz | Oct 15 14
12 Answers

Curbless shower with a PVC liner -- how to terminate the liner at the floor?

I'm installing a curbless shower----Concrete slab-on-grade with a sump for shower.
Using traditional method for shower floor---PVC liner, with pre-slope and top slope mud beds.
2x2 tile on shower floor and 18x18 travertine on bathroom floor.

My question is how to handle the waterproofing interface between my sump and the bathroom floor level (like where the curb would have been).

Asked By john walls | Oct 19 14
5 Answers

An outside, completely isolated, balcony column structure

In an outside, completely isolated, balcony column structure that must be finished in stucco and built using steel studs, would it be possible for any moisture damage in the inside of it if we were able to completely seal the inside from the elements? In a 4c zone, applying stucco to acrylic panels to make a stand-alone column.

Asked By peter mare | Oct 20 14
2 Answers

Gluing rigid insulation to interior of roof sheathing

My home is in Northern Michigan and I wish to insulate an attic that has storage trusses and considerable open spaces behind the perpendicuilar truss members. There is soffit venting around the entire attic perimeter. The attic floor is insulated to R 30. (Peaked roof built over original flat roof)

My first choice was to spray polyurethane to the cathedral underside of the roof sheathing, however I am having difficulty scheduling a contractor, most of whom have bigger jobs they are chasing, so I am considering other options.

Asked By Wes Benner | Oct 22 14
2 Answers

Insulation of the interior stem wall

I am building a 40x60 metal workshop. It is slab-on-grade and I had specified 2" rigid foam on the interior of the stub wall, thus creating a thermal bridge between the foundation and the slab. The footing and stem wall have just been poured. I think there has been a mis-connect between my contractor and myself because it looks like he is going to place 2" thick rigid foam only in the space between the footing and the slab (i.e. the 4" slab will be "faced" with 2" thick rigid foam...

Asked By ron marsh | Oct 22 14
8 Answers

Window U-value comparison to wall R-value and window replacement

We have an 1870s Victorian farmhouse that doesn't have insulation in the walls, and to keep it simple, we cannot add insulation in the walls without going to great expense, more than we can afford.

Asked By Keith Miller | Oct 20 14
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