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9 Answers

Is open-cell foam appropriate for spraying the bottom of a roof deck?

We are building in Indianapolis, middle of zone 5. House will be on a slab, under-slab hydronic heat powered by geothermal, 4" Thermocore SIPS walls with 2" of rigid foam on outside of that. Truss roof. My homeowner wants the bottom side of the roof deck sprayed. My experience is typically spraying the attic floor, not the roof deck. However, in this scenario, we will have ductwork in the attic, so it does make sense to spray the roof deck, so the ducts are in conditioned space. My insulator is quoting us 5-1/2" minimum open cell foam.

In Energy efficiency and durability | Asked By Allen Brown | Dec 20 13
1 Answer

What's better: 4 inch SIPs with 2 inch XPS or 6 1/2 inch SIPs only?

This question is just about efficiency, not about cost. The house will be Thermocore SIPS, but we are trying to decide on 4" SIPS with 2" XPS on outside, or 6-1/2" SIPS with no foam.

4" SIPS = R-24 + R-10 for 2" XPS, total R-34.
6-1/2" SIPS = R-40.

once I figure the savings on the SIPS, but add the materials & labor for the foam, plus a couple of other items, the cost difference is almost a wash.

In Energy efficiency and durability | Asked By Allen Brown | Dec 26 13
1 Answer

Can EPS foam be used under the concrete slab?

EPS is about 1/3 the cost of XPS. We are using underslab hydronics, and would like to save the money if it's a viable product. Is there anything wrong with using the EPS?

Will the EPS be strong enough to walk on while installing the pipes & pouring the concrete? Are there other durability issues or performance issues?

Thanks!

Allen Brown.

In Energy efficiency and durability | Asked By Allen Brown | Dec 26 13
4 Answers

Windows — difference between standard, Home Depot double-hung vinyl and a Marvin Infinity or better?

Good morning. Fixing up an old house and replacing single-pane windows. I would like "better" windows but pushing the budget and wondering if I'm not better off spending the difference in cost somewhere else.

How do I determine if/when they will pay for themselves?
Thank you, Mike

In Energy efficiency and durability | Asked By mike snow | Dec 26 13
4 Answers

Windows — difference between standard, Home Depot double-hung vinyl and a Marvin Infinity or better?

Good morning. Fixing up an old house and replacing single-pane windows. I would like "better" windows but pushing the budget and wondering if I'm not better off spending the difference in cost somewhere else.

How do I determine if/when they will pay for themselves?
Thank you, Mike

In Green products and materials | Asked By mike snow | Dec 26 13
1 Answer

Can an 80% efficiency furnace be installed in an attic in zone 6B?

I just bought a house with a 97% efficient furnace in the attic; I live in zone 6B. After several service calls the contractor who installed the furnace -for the previous owners-told me that this furnace should not be in the attic in Wisconsin due to condensate freezing problems-which has happened twice since I moved in in October of this year.

In Mechanicals | Asked By Anne Sullivan | Dec 26 13
1 Answer

Can a windbreak be planted on the south side of a home with a passive solar design?

My family recently moved into a home with a passive solar design in a winter climate. We love the way it is performing. However, we have strong and persistent wind from the south/southwest for most of the winter. I would love to plant a windbreak to reduce wind (and snow drifts), but don't want to block our solar gain. Recommended distance for trees maturing at 50 feet high is 150-200 feet from the house. Any thoughts on whether or not this would block our winter sun? Thx!

In General questions | Asked By lisa miller | Dec 26 13
5 Answers

Best way to build a cathedral roof for a garage?

Hello to all;

I am in the 6A zone just north of Montreal, Quebec. I am in the process of building a garage separate from my home. It will be an L shaped garage with main section being 24' by 20' and the L part at 7' x 11'.

I am seriously considering a Cathedral roof and would like to know from any experts here if you can please look over the following design I have made.

In Energy efficiency and durability | Asked By Leon Stepanian | Aug 4 13
4 Answers

Cellulose insulation in basement?

We are putting a granny suite in our walk-out basement (newly constructed house) and are thinking of insulating the knee walls (wood framed walls between the top of the stepped foundation and first floor deck) and the ceiling with cellulose. The cellulose in the ceiling would butt up against closed cell spray foam at the rim joist. The floor above will be concrete (radiant heating).

In GBA Pro help | Asked By jessie pratt | Dec 23 13
1 Answer

Should I add batts or loose fill above a 2 foot dropped ceiing?

I have a 100+ year old 4-square house with 2 courses of brick for walls. I'm planning on adding rigid foam to the exterior which will extend up to the eaves and the level of the original attic floor.

I'm planning to go to R-40 on the original attic flooring, but I'd like to keep the 2 ft. cavity created by the dropped ceiling accessible. Would it help to add batts or fill between the joists of the lower ceiling? Would any moisture problems be created between the two ceilings?

In GBA Pro help | Asked By John Loughran | Dec 25 13
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