Q&A: A Forum for Green Building Experts and Beginners

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1 Answer
I have a home with two stained walls

I have a home with two stained walls. One wall is on a corner to the house. The other is in a angle (upper) near the roof.
I'm sending some pictures so you can see the stain.
I have cleaned it up and it comes back again.

In GBA Pro help | Asked By blanca goertzen | Jun 10 13
3 Answers
Opinions or experience with APEX block?

Searching for wall assembly options, weighing cost, thermal performance, durability and so forth, below and above grade, SIPs, ICF, SCIPs, brought me to APEX block. Cementious mix with EPS type of ICF, the EPS form creates a tubular-type grid of concrete with rebar. Supposedly uses something like 25% less concrete than standard ICF, while claiming R-38, and uses recycled EPS at a lower cost than ICF. Anyone have any opinions/experience with the product?

In Energy efficiency and durability | Asked By Sal Lombardo | Jun 5 13
1 Answer
1920 brick rowhome -- bathroom gut rehab -- what insulation?

So happy to have found this site! I'm a rehab newbie and just gutted the only full bathroom in the house which was a build-on in the rear (first floor). Figured it's circa 1940s .... cast iron tub, toilet and sink. We've gutted to the brick wall on three sides. Studs will be replaced. Rotted floor joist will be replaced as well.

1) Figured steel studs would be best. Thoughts?

In Energy efficiency and durability | Asked By Michele Kohler | Jun 9 13
5 Answers
What are good alternatives for the air barrier when building a cathedral ceiling using tongue and groove instead of gypsum?

I am building a log home in North Georgia (Zone 4) with cathedral ceilings and tongue and groove on the inside. Build up from the inside out will be: Pine tongue and groove/ AIR BARRIER / I-Joist Rafters with R-30 fiberglass insulation between / OSB / Felt / Metal Roof. The structure will be vented with soffit vents and ridge vent and 1” air space over insulation. I read the article “HOW TO BUILD AN INSULATED CATHEDRAL CEILING” from this site and the suggested air barrier was gypsum board between tongue and groove and rafters. Is there a good alternative to gypsum? Poly? Typar?

In Energy efficiency and durability | Asked By Alan Shuman | Jun 8 13
1 Answer
Propane 'energy pods'

I'm regularly seeing banner ads in my GBA feed for propane 'energy pods', linking to this site: http://buildwithpropane.com. I'd welcome comments from those better-informed than I on the claims made there which rather fly in the face of all I thought I understood about the cost effectiveness and carbon emissions of this energy source.

In Mechanicals | Asked By James Morgan | Jun 9 13
8 Answers
Fun With Fluids

(starting 1:30 minutes into this video)
Thorsten Chlupp mentions a fascinating concept ...Stratification
http://www.youtube.com/watch?v=1PnDb_NOv9k&list=PL6A9I-CyObf-r9_hQ1jjsK1...

It seems we can "store" a not-so-dense fluid above a dense fluid....

It's kind of Intuitive that a dense fluid will support a not-so-dense fluid.

What's Not so Intuitive is that the "fluids" might be in very distinct layers.
...separated by "Internal Waves"....

similar to this demonstration
http://www.youtube.com/watch?v=RFiriyuqoeY

In Energy efficiency and durability | Asked By John Brooks | Jun 8 13
4 Answers
Insulation question

Am currently in the middle of a major remodel on a late 1800's farmhouse in Eastern Washington State. Have discovered a 'insulation system' I've never seen and maybe someone out there has. I am unsure of how to 'add' to it. The wall consists of typical roughcut stud 3 1/2'' thick with 1x8 shiplap on each side. After the outer shiplap, there is a thin 1'' batt. In its encasement is a thin white cotton like substance. Then there is a couple inches or so of air space followed by a very waxy, tough looking paper. Its color of greenish brown.

In Energy efficiency and durability | Asked By Tim Sullivan | Jun 7 13
1 Answer
Vapor retarder, sealing and ventilation - what to do with an old 1960's ranch?

Hi,

I am an owner builder and I have a humble question related to vapor retarders for the experts, nerds and a like on this forum. I have been reading about vapor retarders, sealing air leaks and ventilation here, building science website and elsewhere for a while and I have talked with the village building inspector about them.

In Building Code Questions | Asked By Heidi Herttuainen | Jun 7 13
1 Answer
I need help with a detail and process to side a home BEFORE the windows arrive from Europe

The energy retrofit project is located in a historical area in Boulder, CO and the area has a strict 'no noise' (read limited construction) after mid June and is in place all summer. Our schedule became tight with multiple permitting but was progressing well until a portion of our German made windows were damaged at the airport. With the delays we will be receiving the windows after the noise deadline.

In Green building techniques | Asked By Brian Hludzinski | Jun 6 13
5 Answers
Attic finishing & proper insulation

Hello,

In Energy efficiency and durability | Asked By Eric Hill | Jun 7 13
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