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2 Answers

Conditioned or unconditioned crawl with mini-splits

I am looking at putting a mini-split into a new home but can not seem to find an answer on how or if I should condition my crawlspace. I know crawls aren't the best route but I don't have the extra $17k to do a basement and a slab isn't an option. So can I build the crawl as a conditioned space without the hvac runs keeping it climate controlled or how should I go about this? I'm willing to put another head in the crawl if that's what needs to be done to make it work.

Asked By DG Builder | Jun 23 17
2 Answers

Another wall — Is this a good idea?

I recently visited a home zone 6 with this wall detail.

It appears to be an interesting way to achieve R27 or so between studs, but is this a good idea?


Asked By Greg Smith | Jun 23 17
2 Answers

Interior rigid foam for ceiling

I have been working on a well insulated house in climate zone 3. We installed 38' trusses for the roof, and I have been concerned by some things I have read about the potential for truss uplift, especially with such wide trusses. Right now the trusses look great, and are very flat and level.

Asked By Jason Whitacre | Jun 22 17
3 Answers

Anyone seen nail corrosion from Roxul?

I'm slowly building my home home and last year I fell for a great price on roxul comfortbatt. I bought what I thought I needed and stacked it in the basement of the dried in house. 8 months later I moved the roxul and was surprised to notice white carrosion and rust on the galvanized Hitachi ringshank nails I used to attach studs to an interior wall sill plate. Nails show carrosion only where I stacked the roxul and no where else in the entire house. I recently learned that roxul has formaldehyde and worry that the off gassing through the plastic wrap is the culprit.

Asked By Ryan Williamson | Jun 22 17
3 Answers

Halogen-free electrical cable

Does anyone have experience using halogen free electrical cable in residential buildings? I'm going to have to do some rewiring in the house, and I'd prefer to keep it low halogen (for less toxicity if it burns and because I'm not a fan of PVC). I know that LSZH is used extensively in industry for certain applications, but I can't find much information on it for use in homes.

Asked By Kathryn Oseen-Senda | Jun 23 17
8 Answers

Rigid insulation beneath floor on shed


First time posting and would like to thank you in advance for at least taking the time to read this.

I am building an insulated shed/writing studio for my wife. Looking to make it 12'x8' and was thinking of building it on concrete blocks with 2"x6" studs for the bottom frame. On top of that I was planning on 2" rigid insulation followed by plywood then flooring. Will I be able to put the sill plate on top of this and drill through to the 2"x6"'s? I haven't worked with rigid in this context before.

Putting it on blocks seems the best option in case we wish to move it later.

Asked By Allan Manley | Jun 22 17
5 Answers

Closed-cell spray foam and XPS: green or not?

I've posted several times on my pretty badly compromised attic. We live in a 50s ranch outside Chicago with a ceiling that has been butchered by can lights and an AC handler & ductwork. I feel the only reasonable solution is to move the conditioned envelope to the roof. I've debated and debated and debated this because the solutions are expensive, a pain to implement, and now it appears environmentally questionable.

Asked By Brian Gray | May 7 17
2 Answers

Dense-pack retrofit cellulose insulation for basement walls?

I recently had an energy audit done existing 1958-built tri-level in climate zone 5 (Ann Arbor MI). Looking for advice from the GBA experts to sanity-check some of the recommendations before making decisions; I'll try to keep it to one question per post. One recommendation was to add dense-pack cellulose into the existing above-grade and below-grade (finished) walls.

Asked By Phil Ray | Jun 22 17
1 Answer

Is there a way to work with and alter your detail drawings? I work in AutoCAD Architect 2010.

Revise your details for my project

Asked By Vija Handley | Jun 22 17
5 Answers

Looking for a cost-effective, “traditionally styled” double-hung window with U-factor of about 0.20

I am building a new house in Hopkinton, NH. (on the border of climate zone 5A & 6A) and am looking for a double hung window with a u-factor of .20 (or better of course) that will look good in a New England farm house styled home. What I mean by this is I would like a clad exterior with a wood interior and SDL grills without having to spend $65,000 on a triple glazed loewen or marvin window. Don't get me wrong I have used both brands of window on customers houses and they are beautiful, but they are not in the budget for my own house.

Asked By Eric Marchand | Jun 22 17
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