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6 Answers

Raising a sunken floor

I am planning on leveling an 18” deep sunken living room (15 ft x 15 ft ) with the surrounding area and then install travertine flooring. To save some concrete, I am planning on using EPS to fill the first 14” of the sunken room and then poor a 4" thick concrete slab. I read an answer to a similar situation posted a few years ago that lead me to believe that the concrete slab my not be needed, and that I could possibly install plywood or hardy baker board on top of the foam with foam compatible adhesive.

In General questions | Asked By Andres Ferro | Sep 5 14
15 Answers

Spray foam & wood roof deck

100 year old residence is located in Zone 5 w/i 50 ft of ocean/bay & has a 100 mph design wind load requirement. It is located high on a hill & completely exposed. Vented eave ridge is not advisable in this area do to high driven rains. The home will not be the primary residence, therefor optimal heating, venting & dehumidifying will not be maintained 24/7.

The energy code requires 49R roof assembly for the proposed occupied attic w/ cathedral ceiling. 49R requirements & existing 2x8 rafters, limits choice of insulation to closed cell spray foam.

In Energy efficiency and durability | Asked By Sheila Sullivan | Sep 12 14
3 Answers

Is Thoroseal good for the capillary break on footing?

I'm looking for something that can be applied to green concrete (7 days after pour ok) that would provide the capillary break on top of the footing before the foundation wall is poured. Is Super Thoroseal (or regular Thoroseal or Thoroseal foundation coating) going to work?

In General questions | Asked By e c | Sep 15 14
12 Answers

Insulation question for new house build

I’m building a brick bungalow in zone 5, please help critique my insulation. The sheathing is 1” Polyiso (foil faced) wrapped in Typar building wrap. I realize the polyiso should be thicker, but I’m told it’s too late. The walls are up and the windows are purchased.

Attic - R50 loosefill cellulose

Main Floor – R22 CC spray foam in 2x6 wall with no VB, drywall and latex paint
- The other option is R10 CC spray foam with R14 Roxul and no VB.

Rim Joist – R12 CC spray foam and R14 Roxul (thermal barrier required)

In GBA Pro help | Asked By Jeff Conners | Sep 12 14
1 Answer

Roof insulation / decking combination

Hello, I live in Winnipeg MB, Canada (Zone 7, North of North Dakota).

I am insulating my garage ceiling to R22+ (standard pink fibreglass between 2x8 ceiling joists). I am also looking to insulate my garage roof to keep some of the heat from the summer out of the attic space in which I will store some things that i do not want subjected to high attic temperatures (I also expect this will help keep the garage cooler as well since the attic will be only about as hot as the outside air at most.

I intent to layer the system as follows:
1. OSB as the roof decking

In Energy efficiency and durability | Asked By Mike Gagne | Sep 14 14
5 Answers

Zone 4B - 2012 IBC and SHGC

The new 2012 IBC adoption in my future building area will mandate that windows can only have a maximum of 0.40 SHGC, including the south facing windows. I am trying to achieve a Passive House design but the low SHGC mandate makes it more difficult. I am going with Intus uPVC triple pane windows. Originally I was going to go with the 0.49 SHGC for the south elevation but now I have to go with the 0.37 SHGC. The building department will NOT budge on this factor and will not allow any windows > 0.40 SHGC.

In Building Code Questions | Asked By Peter L | Sep 13 14
4 Answers

Inset 2x6 sill plate

We're in the final phases of house plans for our new build in Illinois(5A). I'm very interested in adding 2" of XPS foam, but not so excited about it extending beyond our basement foundation wall. Would it be acceptable to inset a 2x6 treated sill so that the foam does not extend beyond the 8" basement foundation wall?

I've attached a drawing to help explain...

Thanks a bunch - I really appreciate all the advice I've learned on this site!

In Green building techniques | Asked By Craig Harper | Sep 14 14
5 Answers

If I have a 5 1/2 in. square framing bay and the exact same 5 1/2 inch square batt, does it matter which way I install it?

Does fiberglass work directionally? Or does it matter?

In Energy efficiency and durability | Asked By rich graves | Sep 13 14
2 Answers

So. Calif. — Adding insulation to existing walls that have fiberglass batts

I have a solidly built building - wood frame stucco walls. Built in 1960, (I helped) with rolls of pink fiberglass in the walls and attic. It is no longer effective against the heat.
What can we do to add wall insulation. I have had the walls of other homes insulated with blown in cellulose with success, but there was no existing insulation in those situations. Will blown in work with the old fiberglass in the wall cavity?
Is there a better option?
Thank you.

In General questions | Asked By Kay Park | Sep 13 14
3 Answers

Insulating interior AND exterior basement walls OK?


In Energy efficiency and durability | Asked By Nikola Kolarich | Sep 12 14
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