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5 Answers

Where is soffit venting necessary?

The December issue of Journal of Light Construction has an article featuring building techniques of four high performance builders. Three of the buildings pictured have truss roofs; one of those clearly has a ventilation channel from the soffit to the space above the insulation; one is unclear and one, a certified Passive House, clearly does not. There, the cellulose insulation is against the inside of the roof sheathing for what looks like 2'-3'. So my question is, in a vented attic over a very tight house, when is venting to the soffit necessary?

In Green building techniques | Asked By Bob Irving | Dec 21 13
12 Answers

1929 Brick Building in Zone 5A needs insulation— Half of the low-slope roof is very tight and not accessible

We have a 1929 Brick building in Zone 5A with an 8,000 square foot low slope EPDM Roof. It has old single pane windows with cheap metal storm windows attached. The exterior walls are 13" thick, with 9" of hollow bigger bricks, and 4" of regular nice looking bricks).

The first floor has been renovated already, and now we would like to add apartments to the top floor. Before we do this we would like to make some energy efficiency upgrades. Can you recommend what would be best for insulating the attic and or walls?

North half of attic has room to move around in

In GBA Pro help | Asked By Aaron Hirshberg | Dec 3 13
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
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