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4 Answers
I'd rather put 2" of rigid foam on the interior of the rafters than on top of the roof deck.

I have 2x12 rafters and was planning on insulating with dense pack cellulose or rock wool for a cathedral ceiling. Then putting rigid foam on the inside , then drywall. Does this make sense? I was hoping not to vent. Will this work.

In General questions | Asked By Seth Kelley | Apr 6 14
6 Answers
Why are my Willmar Windows (Jeld-Wen) sealed glass units repeatedly failing?

Subject: Willmar Windows Jeld-Wen Ontario Canada

In 1997 we purchased 78 top of the line windows and doors from Willmar Windows, a division of Jeld-Wen. These were "R+10 with Heat Mirror, Metal Clad Wood" windows and doors.

Since the first year there has been a steady rate of seal failures. In 2004 Willmar decided to replace all of the glass units. In 2007 Willmar finally accomplished this.

They were replaced with glass units called Tripane T2SA with "Triple Solar Shield, 2x Low E and Argon". Since 2007 we have had 12 seal failures in these units.

In General questions | Asked By Jane Gray | Mar 30 14
12 Answers
Converting from oil heat & electric hot water to geothermal and redesigning utility room and master bath

I am moving from Southern California, where I typically don't heat or cool my home to Central Pennsylvania.

The home I am purchasing has Oil Forced Air Heat and Electric Hot Water and appliances.

There are no Natural Gas Lines near the home - so Natural Gas is not an option.

In Energy efficiency and durability | Asked By Jennifer Hogan | Apr 6 14
8 Answers
Insulating unvented cathedral ceiling

I bought a house with a vaulted ceiling. Drywall is nailed to 2x6 roof rafters. It is unvented for the most part. I have no idea what kind of insulation is up there. I want to insulate it but don't want to tear off the roof (which is relatively new), or the ceiling. There are big overhanging eaves that can be opened to look up into the cavities. I'm wondering about my options here. Is it possible to spray closed-cell foam up from the eaves and fill the space? Any suggestions?

Robert

In Energy efficiency and durability | Asked By Robert Jones | Oct 16 09
1 Answer
2012 IECC - Slab-on-grade Zone 4B

I will have an ICF stem wall that will transition into the ICF house wall. The interior will be a slab-on-grade design. This is for a Zone 4B (desert) climate.

1 - Should the vapor barrier be on-top or below the rigid EPS?
2 - What thickness is good for a vapor barrier?
3 - Will 3" of rigid EPS suffice for a Zone 4B climate?
4 - Any links to some details showing the above condition?
5 - Should crushed & compacted rock be used below the EPS and concrete slab?

In Green building techniques | Asked By Peter L | Apr 8 14
1 Answer
New construction sealed crawlspace R-value and air exchange question

In climate zone 2 what is the required R value if doing sealed crawlspace and insulating foundation walls instead of floor? Table N1102.1 lists crawlspace walls. Is this for sealed and when not insulating the floor? That value is 0 for my climate zone. Is that accurate or is that for vented?

2nd question:
Should an air exchange (in addition to air supply to crawlspace) be installed in the above scenario? I think the code asks for it but I read somewhere (possibly on here) that the positives are outweighed by the negatives. Is that true? Is it preferable to not install that?

In Building Code Questions | Asked By Chris Purvis | Apr 7 14
4 Answers
The most value-engineered siding furring strips over thick rigid foam... but what width?

Assuming labor is free, I've found that the cheapest furring strips would be 15/32" plywood. It's quite a bit cheaper than 1x4's (less than half the price, close to a third, if ripped to 2.5"), and can be narrower than 3.5" without worrying about splitting like 1x3's or 1x2's would. Also, it just barely meets the 7/16" penetration requirement that James Hardie has.

In Green building techniques | Asked By Nick Welch | Apr 4 14
24 Answers
Are code-breaking BPI builders causing trouble for unvented roofs?

I have a flat unvented roof on my 100-yr old rowhouse in Philadelphia, climate zone 4. There is about 18" between the top of the ceiling and the bottom of the roofdeck. I'm looking at my options for air sealing and insulating this roof--there is currently no insulation at all.

In Building Code Questions | Asked By Andrew Levitt | May 4 11
3 Answers
Can we drywall over an interior chimney?

We had a new roof installed and it leaked around the chimney, into our attic then seeped down into our hallway. Plaster covers the interior chimney. We have no fireplace, just a gas furnace and water heater. We plan on replacing all of the walls (which are plaster, also), with drywall. We're just not certain about the chimney. The chimney is new also and has no liner. The company the built the new chimney said we didn't need a liner since there is no fireplace. Any suggestions would be appreciated. Thank you.

In Interior design | Asked By Becky Gaston | Apr 6 14
26 Answers
The "Why" in Green Building

This site excels in the "how" of green Building techniques, but it appears to me that when things move towards explaining the "why" discussions seem to move onto much shakier ground. Especially if the economic arguments don't seem to add up, rationalizations veer towards more general "It's the right thing to do" or "I want to be part of the solution" type responses.

In General questions | Asked By Malcolm Taylor | Mar 29 14
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