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4 Answers


We are currently restoring a Usonian style house built in 1962 here in Northern Illinois. The sunroom is currently being restored to its original design with a few exceptions:

Asked By Ryland Bouchard | Apr 13 14
5 Answers

I have seen a few discussions about insulating cathedral ceilings but none that relate to the method that I had in mind for my 24' cathedral here in Vermont.
* Penetrating water sealer on all surfaces that have the potential to rot.
* One inch strapping to create an air gap for ventilation.
* Multiple overlapping layers of ridged foam(open or closed cell?)
* All seams taped because expansion and contraction will break a DIY spray foam seal.

Asked By Gary Spurling | Apr 11 14
1 Answer


I just installed a new slab. Slab is approx 5" thick, and was set up as follows. We dug trenches and laid drain pipes in gravel, fabric wrapped, etc. On top of that another layer of crushed stone, 2" insulation and then a fully waterproof layer (Grace Pre-Pruf). On top of that poured the 5" slab.

Plan is to put down pressure treated sleepers, with t&g plywood on top and then put an engineered wood floor on top of that.

Asked By R W | Apr 11 14
3 Answers

Hi GBA Pros,

We just got a call from a client who wants to build a hot tub room in their garage.

My colleague sent me this email about it.

Asked By Chris West | Apr 9 14
9 Answers

If you need to build a home with a crawlspace because of the slope of the land and you also have an attic, what is the preferred place to put your furnace: in a conditioned crawlspace or a conditioned attic?

If you make a conditioned attic, how do you treat the space above a porch and the garage? There are obviously no ducts going to these places. Do you make them part of the envelope anyway OR you build walls to exclude them from the conditioned space?

Thank you for your time and help.

Asked By Liliane Tricot | Apr 1 14
2 Answers

To Martin Holladay:

Last week you gave this reply to a question about putting cellulose
insulation on top of fiberglass batts in new construction. You have answered
that in full and I thank you for it. However, you made a further comment as
follows: " I hope, however, that your builder remembered to do a careful air
sealing job at the ceiling plane before any insulation was installed."

Please let me know more particularly what should have been done to the
ceiling to seal it properly.

The only air sealing that I know about is that the fiberglass batts have

Asked By Robert King | Apr 3 14
3 Answers

I am consulting on a home where the HO wants to have the insulation at the roof deck. They are thinking 2” of closed cell followed by 6” of open cell.

The HO put forward this idea.

2" closed cell at the roof first to provide the vapor barrier then followed by 6" of open cell which will be enough to encapsulate the top chord of the roof truss and minimize thermal conduction.

Does anyone have any experience with this type system?

Is there any concern of the two layers of foam de-bonding from one another?

Asked By Mark Parlee | Mar 29 14
39 Answers

I did a lot of research when I built. Bottom line is that I chose the cheaper easier method and now I'm paying for it. I continue to hear that it's OK to dense pack cellulose in a slope and not vent it or not flash it with closed cell foam. This is incorrect and I can prove it now! Moisture has collected on the back side of the roof sheeting and ice chunks have formed, mostly on the north side of the house. Any where there's snow build up on the south side I have ice formation on the inside of the roof sheathing as well.

Asked By James ODonnell | Mar 4 14
3 Answers

I am building a 187 square foot tiny house for my family of 3 in Barrie, Ontario and have some questions about ventilation. The house is decently well insulated and airtight, with 6 ½” inches of XPS on the walls and roof, 5 ½” in the floor, and a Solitex Mento 1000 exterior membrane.

Asked By Travis Marttinen | Mar 25 14
4 Answers

I have a 20x30 barn with wood siding (pine boards) and asphalt shingles over 3/4" T&G decked gambrel roof. The 2nd floor loft has a 17ft height at the ridge with zero insulation. I read your article about radiant barriers and an example of an uninsulated barn with steel siding and roof was mentioned. Would a barrier be functional toward reducing air temperature in my barn and if so, where exactly should it be installed? I would try to do this myself. Thank you.
Rob Cramer

Asked By Rob Cramer | Mar 24 14
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