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9 Answers

Basement ceiling

I've put insulation between my joists, and just was told, I put them in upside down. Apparently, the paper should face the floor above.
Would just slicing the paper suffice or should it all be turned around.


In GBA Pro help | Asked By Deb Malloy | Nov 26 12
4 Answers

Why am I not getting hot water consistently from my new Marathon hot water heater?

I have a closed loop geothermal system with two 40 gallon hot water heaters. They were old and rusting so I replaced them both with just one 40 gallon Marathon hot water heater. I have not been able to get hot water when I need it all the time. Can someone please help me figure out why?

In Energy efficiency and durability | Asked By Vonnie Guy | Dec 12 12
5 Answers

Cooling Down A House With No Attic.

Hi guys, first time here, so I want to thank you in advance for all your help...
Here's my situation, I live in Fremont, CA and I'm planning to buy the house I'm currently renting, but there's a problem, the house is "extremely hot" during the summer. It is 95 degrees inside. The house doesn't have an attic, it's a flat roof. When looking up to the ceiling, one can see the beams,etc and my wife happens to like that about the house. So, how can I fix the heat problem? In the winter, of course, the house is very cold.

In Energy efficiency and durability | Asked By Jose Figueroa | Dec 11 12
2 Answers

HRV and SIP panels

I'm designing a single story house in SE Alaska (zone 7) and planning on using SIP construction for the floor and exterior walls. I'm also thinking of using a scissor truss so that I can have a cathedral ceiling in the front and an attic in the back section of the house. I'd like to use SIP panels for the roof, or sheathing, 2x2" insulation sheets, sheathing and standing seam metal roof. We will be taping the panel joints (and everywhere else) as well as foaming. How do I run ducting for an HRV, as I expect I will most definitely need one?

In General questions | Asked By Sylvia Ettefagh | Dec 12 12
2 Answers

Foam over Platon dimple mat on foundation

We are stumped at a stage in our building process. Winter is here and we need to deal with our foundation. Our site is dry dry dry, but we are not ready to just attach foam to the cement and backfill without any effort to damp/water proof the foundation.

We are essentially forced to use a mechanical system as the weather and temperatures (-10 degrees celcius and wet) are making any other sort of damp/water proofing impossible (as far as we know).

In Green building techniques | Asked By jessie pratt | Dec 11 12
4 Answers

Efficient roofs


My name is Rod and I live in Waialua on Oahu. It gets pretty hot here. We have vaulted ceilings and are about to replace the roof so we can put a new solar hot water system and 18 pv molules up there. What roof would you use to repel heat from coming in the house?

Thank You,
Rod Martin
808 854 9636

In Energy efficiency and durability | Asked By Roderick Martin | Dec 9 12
8 Answers

Proper use of various rigid polyiso facers?

I've come across a few different facers on rigid polyiso:

- foil
- trilaminate (foil-kraft-foil)
- glass fiber
- reflective vs non-reflective

Based on the manufacturers guidelines, I've seen recommendations based on wall construction and siding materials, but I don't understand the reasoning behind these guidelines.

How important is it to match the facer to your building context?. What's the difference, performance-wise? In what situations would you use one over another?

Any help will be greatly appreciated.


In Green products and materials | Asked By Andrew Thompson | Dec 7 12
4 Answers

In-Floor Heat System - Electric Energy Source - Hydronic or Electric Resistance?

I am planning a remodel of a 100+ year old house in Seattle. We are planning on removing the existing forced air furnace and replacing with in-floor heating. The energy source will be electricity. It seems to me the most efficient method would be electric resistance instead of hydronic. Wouldn't there be a loss in efficiency (and a more complex system) if you use electricity to heat the water in a hydronic system versus the near 100% efficiency of electric resistance? The only benefit I could see to having a hydronic system would be to possibly tie it in with a solar water heater.

In Mechanicals | Asked By Sean McClintock | Dec 8 12
4 Answers

Cellulose batts; experience with?

I just found these, and my curiosity is piqued. Anyone have any experience w/ them? I'm curious about how they are for general fit (tight? gappy?) and how they are for cutting around oddities. I am really leaning hard toward cellulose now, the more I read here and elsewhere. Batts, blown-in, or some combination thereof, depending on costs and what you get out of it. thanks. j

In Energy efficiency and durability | Asked By jklingel | Mar 8 10
26 Answers

Vertical Rain screen wall in climate zone 4C

I am an architect designing a house on Salt Spring Island which is in Climate Zone 8. The code mandates rain screen and the client desires vertical red cedar ship lap boards. The house has very high ceilings at 14' and 12' which requires a fire break at 10'. My questions are to do with how to best design the wall to mitigate humidity inside the house and create the most energy efficient house possible for the owner.

My current wall build up is:

1/2" Wallboard with latex paint
2x6 stud wall construction with R21 Owens Corning fiberglas insulation

In Energy efficiency and durability | Asked By Marcus Springer | Dec 6 12
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