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1 Answer

SIP walls insulating the floor joists

I'm attaching a picture posted by Insulspan, the SIP manufacturer we're getting a quote from. It shows the SIP wall on the edge of the basement wall with the floor joists on the inside edge, providing continuous insulation of the rim joist. Has anyone seen this done? I thought at least 4 inches of the floor joist had to rest on the basement wall to be structurally sound. I plan on using superior walls which are 10.25 in thick and 8.25 in SIPs.

Asked By Brian W | Nov 28 15
1 Answer
3 Answers

Inward solar vapor drive with Zip R Sheathing

I am curious if Zip R sheathing would experience any issue with inward solar vapor drive.

We have an upcoming project that will use Zip R Sheathing (in the polyiso 1 1/2" variety) - and will also have a reservoir cladding - stone on the exterior. There will be a minimum 1/2" gap between the back of the stone and the zip - but it won't be ventilated. Still I was curious if the zip coating and osb might allow vapor to be driven through them only to condense at the outside of the polyiso.

Asked By Patrick Kelly-Decker | Nov 25 15
4 Answers

Mineral wool in an attic


This is a complete newbie question.

I read the article about Mineral Wool in Fine Homebuilding 254 (pp. 48-53 September 16, 2015) and it says that if you use it for insulating the floor of an unconditioned attic, you need to use a vapor barrier underneath it.

Would the painted drywall ceiling in the living space below the attic perform that function or do I need to install something in each rafter bay before putting in the mineral wool? Would that thin bubble-wrap-like insulation sheeting work?



Asked By George | Nov 25 15
9 Answers

Spray foam and Roxul for flash and batt?

Hey guys,

I am in the process of finishing my attached garage in zone 5a. It will not be heated year round, just when I am working in there. When it will be heated, I will be using a 240v 6k watt electric heater.

I am torn on how to go about insulating my unvented cathedral roof. I ready that fiberglass batts against the sheathing are a no no but what about roxul? If that's no good either, can I just spray 2" of closed cell and fill with roxul then sheet rock?

Asked By Steve | Nov 23 15
8 Answers

Best roof assembly on a budget?

Thank you for your website and for the exceptional information available here. I am an active student of GBA and a big fan.

I live in Central East Texas, Hot Humid, and am in process of remodeling a mid-century modern home with low sloping roof lines: 1.5/12 to 3/12. Essentially the entire home and roof assembly will be a vaulted ceiling setup since the interior ceiling is the actual roof deck. Roof is about 50 square.

Asked By Chris | Nov 24 15
10 Answers

Adding insulation to a 1930s home with a slate roof

Location (New Jersey)

Asked By David Adler | Nov 23 15
6 Answers

How should I insulate my exterior walls?

I live in zone 4a, northern Virginia. My house is a single story, 2x4 exterior walls, no plastic wrap on the interior, no sheathing on the exterior, no house wrap on the exterior, and the exterior siding is RB&B board. The house is 40 years old and has just 40 year old batting insulation with siding. I want to spray foam, from the exterior, but one person says do not use closed cell because it is too hard to cut smoothly and water could settle in any uneven places, the next person says to only use closed cell.

Asked By Michael | Nov 23 15
7 Answers

Window advice - Zone 3

Well we are looking at Marvin all Ultrex, Andersen 200, Softlight Elements and Sunrise Vanguard.

We are in Zone 3 on a heavily wooded lot, 4 small window on the west, 2 covered by porch, 15 on the north northwest, 4 on the south and 2 sliding doors, one 6 footer on the south with a 8 ft covered porch and a 12 ft sliding door on the east covered by a 12ft deep screened porch.

What should we look for in U-factor and SHGC?

Asked By Quinton Bryant | Nov 10 15
0 Answers

Does EPS shrink with time?

On the following link a comment was made that I have concerns :
"On the foam, two layers is better than one, with seams taped on both layers, and overlapped by a foot. Over then next 40 years the EPS is going to shrink a bit, but the performance hit won't be too bad if the seams are overlapped and still reasonably air-tight."
Answered by Dana Dorsett

Asked By Edwin Perdomo | Nov 23 15
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