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4 Answers

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.

In Energy efficiency and durability | Asked By Jeff M | Oct 22 14
3 Answers

Add R-14 Roxul between the garage attic and the house?

I am currently in the process of insulating my attached garage using Roxul R14 "ComfortBatts". I live in Winnipeg and from experience -- when I did this in my last house -- it can improve the temperature by 10-15 degrees Celsius in the winter, without any heating. (And that was with a non-insulated garage door; my new house has insulated garage doors!)

In Energy efficiency and durability | Asked By Mike Lucas | Oct 23 14
1 Answer

“Radon Mitigation Systems” article

“Radon Mitigation Systems,” June / July 2014, pg 86 -87: Holes on pipe.

I look back at the article from June / July 2014, “Radon Mitigation Systems,” page 86 -87, and notice the drawing with the holes on the pipe point up instead of pointing down?

I was wondering, is this so people that read the article would see what was meant by the perforated pipe?

In General questions | Asked By karl neemann | Oct 23 14
6 Answers

Using foam sheeting & faced fiberglass batts

I am insulating my garage ceiling and have laid 1" foam sheeting above the horizontal 2x4 of the trussses. My plan is to put faced fiberglass batts between the trusses up to the 1" foam sheets. Then I would like to put another 1/2" foam sheet over the fiberglass batts, sandwiching the faced fiberglass between the foam sheets. Is there anything wrong with doing this? Thank you for your help!

In Energy efficiency and durability | Asked By Mark Woyak | Oct 23 14
3 Answers

Sealing meeting point of brick wall and asphalt driveway

Hi,

My house, a semi-detached, has an asphalt mutual drive between it and the neighbors house to the south that comes right up to the side of the house.

I'm concerned about the meeting point between the asphalt and the brick as it looks like water can collect there and seep into the brick (I have some Interior spalling and suspect that this is the source), but I'm not sure how to address this.

Do I use caulk.. or something with the consistency of tar.. or something like mortar for bricks..?

Some photos here:

In General questions | Asked By Jon Haque | Oct 22 14
5 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.

In Green building techniques | Asked By leo kloop | Oct 22 14
11 Answers

Flat roof insulation

I have built an extension to my house with flat roof, continuation of the existing house. The rafters are 16 in apart and there is 6 in left for the insulation under the sheeting. The plans are requiring R30 insulation and the building inspector requested hard foam Thermasheath- 3, 5 in thick, leaving 1 in for breathing. The drywall was not installed yet, when water from condensation came down all over the place. There are vents on both sides of the roof, in each bay under the insulation level, not allowing the hot air to escape.

In Energy efficiency and durability | Asked By Angela M | Nov 22 13
1 Answer

Good idea to insulate old house with cellulose?

I have a house that is well over a century old, its balloon framed and has no insulation in the walls, i am planning on getting dense packed cellulose, but i want to know if i am creating any moisture problems or other issues that should give me pause.

Its vinyl siding over original wood siding on wood planks with 2x4 framing and plaster and lath inside.

In Energy efficiency and durability | Asked By Alan B | Oct 23 14
5 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.

In General questions | Asked By Aleasha Jeffries | 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.

In PassivHaus | Asked By Len Moskowitz | Oct 15 14
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