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7 Answers

Should rigid foam extend the full depth of basement foundation?

I met with a builder and in his quote he accounted for exterior rigid foam extending 3' deep below grade. He said that foam is not needed any deeper because the ground is a constant 55 degrees.

I've seen several posts on here about going full depth and insulating below basement slab, but I never thought about this.

I am in Northern Illinois climate zone 5 for reference.

In Green building techniques | Asked By Adam Peterson | Jan 2 15
4 Answers

Vapor barrier height and polyiso question — unvented crawlspace

I am looking to convert my poorly vented crawlspace to unvented one. Because I am in Northeast, I also have to manage radon levels, so I am planning on installing 20mil vapor barrier and already have active radon system installed (but not running yet, until I have the vapor barrier)

Question 1: Considering I will be insulating the walls with polyiso, how far up the wall to I attach the vapor barrier? Foundation is cinderblock and is from 3' to 5' high.
Question 2: Do I attach vapor barrier behind the polyiso or on top of it?

In GBA Pro help | Asked By Apolinaras Sinkevicius | Jan 5 15
2 Answers

Does Bora-Foam insulation qualify for the IRS energy efficiency tax credit?

I sealed my crawlspace and used Bora-Foam insulation board on the walls. I am unable to find any information on whether it is eligible to receive the tax credit.

http://nisuscorp.com/pest-management-professionals/products/bora-foam

In Building Code Questions | Asked By Justin Shive | Jan 4 15
2 Answers

Does Bora-Foam insulation qualify for the IRS energy efficiency tax credit?

I sealed my crawlspace and used Bora-Foam insulation board on the walls. I am unable to find any information on whether it is eligible to receive the tax credit.

http://nisuscorp.com/pest-management-professionals/products/bora-foam

In General questions | Asked By Justin Shive | Jan 4 15
5 Answers

Super insulated "storm" door?

Hi,

My home has a beautiful but very inefficient wood front door. It's original to the home (75 years old), and installing a new door would require removing and probably destroying a hand carved door surround. For those reasons my wife isn't willing to part with the door at this time. Since it currently has a cheap storm door that needs to go, I was wondering if we could replace that with something more robust and insulated, making the storm door the thermal enveloped or while being full glass (double or triple pane) to preserve the view of the original.

In Green building techniques | Asked By Ryan Griffin | Jan 2 15
2 Answers

Basement walls: combining EPS/XPS with polyiso?

I'm in climate zone 5A. The builder installed 1/2" foil-faced polyiso on the upper half of my basement walls, glued to the concrete. There is nothing on the lower half. I have already installed 2" XPS w/canned spray foam in the rim joists and added back in the "Flame Spread 25" fiberglass the builder installed there.

In Green building techniques | Asked By Carl Bomkamp | Jan 4 15
2 Answers

Just can't find it.

Looking for a drawing of cedar shingles over foam over cmu...I know it's there. Thanks

In General questions | Asked By Robert Brown | Jan 3 15
9 Answers

Does my house need to breathe?

We're building a house in the Southeast and want to try for the tightest shell possible. During the interview process several contractors keep telling us the house can be tight but needs to be breathable. Is there any science to this or are they just stuck in their ways? We're planning on using some kind of air exchange system. Thank you kindly!

In Green building techniques | Asked By megan wood | Jan 1 15
11 Answers

Better option than a heat-pump water heater for a boiler?

I have a home in Zone 4b that currently uses propane (no natural gas service available) to fuel a 10 year old mediocre boiler (hydronic baseboards) and mediocre tank water heater, both in the garage. I'm considering replacing both the boiler and water heater with two electric heat pump water heaters (2.5 to 2.75 EF) and wonder if there are better options I haven't considered. Heat pump mini splits and a wood stove currently handle part of the heat load, but don't take care of the whole house. PV is scheduled to be installed soon and will handle the total load for these units.

In Mechanicals | Asked By Jane Whitmire | Dec 31 14
5 Answers

Insulating around crawl space vent

Hi,

I have an older home in Seattle where the temp is only below freezing a handful of days a year. Vented craw spaces are the norm in order to deal with constant ground moisture. Crawl space vents were added to this house by cutting into the rim joist. The joist cavities next to these vents lack any insulation/batting for roughly 4 ft. I am wondering if it is worth it (or against code) to use foam board between these joists to help insulate.

Thanks
Mike

In General questions | Asked By Michael Mason | Jan 2 15
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