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

Q & A Instructions

[Click map to enlarge]

The GBAGreenBuildingAdvisor.com web site has a wealth of articles on a wide variety of construction topics. Before posting your question, you may want to check out the articles on this page: How To Do Everything. You just might discover an article there that provides the information you seek.

Please register for a free account or sign in to ask and answer green building questions.

If you want to post a question, the usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration: Under the box labeled “More explanation,” look for the words “File attachments.” Click that, and you should be able to attach a photo.

Thanks for joining the conversation!

18 Answers

How would YOU insulate my new house given the conditions?

This is my first post on GBA but I think I've read every article on the site in preparation for building our new home, located in Thunder Bay, ON, Canada (40 minutes north of the Minnesota border, Climate Zone 7). I've learned a lot here, but like other posters have suggested, I might be MORE confused than when I started!

In Energy efficiency and durability | Asked By Nik Fiorito | Mar 11 15
1 Answer

700 square foot attached garage — heater choice?

Hello everyone. My name's Ryan Picha. I've read a lot of posts on GBA, and it's great how much everyone helps others with their problems and questions.

My question: a 700 square foot attached garage in Minnesota. New construction rambler with walkout. 9 foot ceilings, fully rocked and insulated. About 700 square feet.

I want to keep it at 45 degrees or so in the winter. What would be the best way to heat my garage? I have natural gas.

Thank you everyone for your time.

In General questions | Asked By Ryan Picha | Mar 13 15
2 Answers

Looking for a local designer/ builder in southern Rhode Island

A local designer/ builder in southern Rhode Island, by Todd Buckley.

My wife and I are interested in renovating a 1986 built passive solar house but cannot find local builders that can meet our needs. Do any of you know of someone like you that works in South Kingstown, R.I.?

In Project management | Asked By todd buckley | Mar 12 15
5 Answers

Vented/unvented attic?

Am building our SW facing energy-efficient home (1850sf+/-) shortly: Reddiform ICF for all outer walls from footings to roof, stuccoed, 3" Dow SM under basement slab, all joints taped, infloor hot water radiant, engineered 20" wood floorjoists which are topchord bearing on LVL ledgers for clearspan basement, with extra horizontal strongbacks to make a truly monocoque floor system, stapleup radiant tubing, 7.5/12 roof trusses 16" o/c with 4' overhang, single attached unheated garage, hardcoated windows = 6.4% of wall area, 2 freestanding see-through gas fireplaces (supplementary heat & estheti

In Energy efficiency and durability | Asked By Edward Skakie | Mar 11 15
17 Answers

Special surge protection needed with LED-bulb lighting?

I have a couple remaining questions in my aim to do good research before investing in LED replacement bulbs for my incandescent bulbs.

I can buy a very good quality 60w edison-base incandescents for under $4 each. A comparable 800-lumen LED of good quality, with a 5-year warranty, will cost me roughly five times as much. I do not want the supplier to skip-out on making good on the warranty due to a factor (excuse?) such as "do you get voltage spikes in your neighborhood?" Obviously, replacement of each LED, if it's out of my wallet, is a bigger deal than with conventional lighting.

In General questions | Asked By Joel Russ | Apr 17 13
9 Answers

Should I insulate the interior side of the basement wall if there is already XPS on the outside?

I have an unfinished basement in N.E. Ohio. Uninsulated slab floor with poly vapor barrier underneath. 13 course block walls with 2" XPS foam on the exterior side. We are looking into finishing the space for a guest room/suite with a bathroom, excercise area, office and family room/play space. Being that there is already r-10 on the outside of the walls will adding a layer of 2" XPS (r-10) create any problems? I have been reading everything Ican find on GBA and Building Science but everything seems to refer to either or, not both.

In General questions | Asked By Eric Singleton | Mar 11 15
3 Answers

Blower door test - Des Moines, Iowa


I'm trying to help a friend in Des Moines, Iowa obtain a blower door test & follow it up with directed air sealing. How does/should one go about finding a contractor to perform a blower door test? Is there a city/state database of contractors able to perform a blower door test? For renovation projects, how do most contractors who perform blower door tests receive new business? Lastly, what should one look for when choosing a contractor to perform a blower door test and/or air sealing?

Houston TX

In Project management | Asked By Robert Hallenbeck | Jan 21 15
22 Answers

24" o.c. rainscreen furring concerns

Getting ready to start a house for a customer, double 2x4 walls, etc. We left the exterior side 2x4 @ 16" oc due to rainscreen furring concerns.

I'm beginning to question whether we can move to 24" oc on the outside wall and use our rainscreen furring 24"oc...?? Furring will be 2x4 KD lumber, mainly because we can get 2x4 cheaper than 1x4 and it's not that much more effort.

So can the furring go to 24"oc and not have problem with the clapboard siding going crazy?


In General questions | Asked By RMills Miller | Mar 4 15
9 Answers

Garage under bedroom

I have read the article by Lstiburek: BSI-009: New Light in Crawlspaces. Very informative!

Figure 7 shows a detail for Cavity Insulation with Vapor Barrier (see attached image below).

In Green building techniques | Asked By David Dodgen | Mar 10 15
2 Answers

Minisplit recommendations for small California casita?

I'm building a new 500 sq. ft. casita in Northern California (Sacramento). Very well insulated (R31 walls, R-56 roof). Summer cooling is needed, and some winter heat, but I'm also installing sealed, vented gas fireplace (more for aesthetics). I am considering a small 3/4 ton (9,000 Btu/h) ductless minisplit, and was wondering if there were any recommendations for a unit or system for such a space. I was looking at a Mitsubishi unit.

In Mechanicals | Asked By Dan Burgoyne | Mar 9 15
Register for a free account and join the conversation

Get a free account and join the conversation!
Become a GBA PRO!