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!


5 Answers

Basic HRV concepts/design

We are building a SIP panel [house], open concept, vaulted living room, with a second floor. Radiant in floor heat. 1500 sq ft main, 500 sq ft upstairs.

Our local HVAC contractor (small community, not many contractors to draw from) is telling us we must have an HRV supply and a return for each room. Ie: each bedroom is to have a supply and return, each bathroom is to have a supply and return. We thought the basic concept was more like each bath would have a return and each bedroom was to have a supply.

Asked By Rebecca Borton | Feb 25 17
26 Answers

SIP roof issues

Hi Everyone.

I was listening to Mr. Holladay on the FHB podcast and started getting nervous about my SIP roof built 3 years ago.. We live in central Washington and the climate is pretty cold in the winter (mid 20's) and hot in the summer (upper 90's). The humidity levels are low year round. We get about 2-3 of snow on the ground by February. The roof is 1/2:12 pitch and is 64'x32'. The bottom seams of the panels were taped, although the tape didn't seem to stick all that well. The humidity in the house is around 28-32% year round. The ceiling is painted drywall.

Asked By Matt Melton | Feb 17 17
2 Answers

Integrating Ducted Mini-Split with HRV

Hello,

Asked By John Brown | Feb 25 17
2 Answers

Homemade walk-in cooler

I'm about to build a 10'x14'x8' cooler for my farm, using a 24,000btu window unit and a CoolBot to reach a temperature of 40-45F. I'm using layers of 2" eps rigid foam with foil backer (it was the best deal I could find on Craigslist) to reach a minimum of r-25 throughout, and 15 mil plastic as a vapor barrier.
First question: should the insulation be on the interior of the framed walls and vapor barrier over the insulation, or vapor barrier then insulation.
Second question: is there a way to build a foundation below grade--to avoid any steps-- without pouring concrete?

Asked By Matthew Ervin | Feb 25 17
2 Answers

Living proof you can be energy efficient in a cost effective way

Several years ago I participated in the forums here while also reading up on Passive Solar House construction techniques. I used what I learned here from Martin Halladay and others (especially TJ Holloway of Efficiency VT) as well as the tool REMDesign to design a super energy efficienct second home in northern VT.

About 16 months ago my wife and I sold our MA home and moved to our VT home making it our primary residence.

Asked By Jay Hersh | Feb 25 17
1 Answer

Rigid Foam

I'm need to insulate my second floor cathedral garage ceiling and live in upstate NY. It has 2x10 joists and I want to get the most bang for my buck. I've looked at closed cell spray foam and its just not in the budget. So my plan is to use 1 inch rigid foam with a 1 inch gap to create my baffles, then use Roxul R30 that should fill the 9.25 cavity perfect to give me a estimated R rating of about 35 and then cover it with OSB. My question is do I need a vapor barrier in between the studs and the interior OSB?

Asked By Steven Miller | Feb 25 17
24 Answers

Basement subfloor retrofit insulation options

We recently renovated our 1897 brick workman’s cottage here in Chicago. We’ve done our best to upgrade the energy efficiency of it including insulation upgrades– although based on some of threads, may have made a few not optimal decisions (closed cell soy foam interior – we’re in an historic district so we cannot make any changes to the exterior.). We’re now seeking to tackle our basement floor, specifically insulate it.

Asked By brandon antoniewicz | Nov 30 10
3 Answers

How to insulate a cathedral ceiling from within the rafter bays

I have a zone 7 1840s house-and-a-half style house, with the second floor walls going about 4 ft up, then sloped cathedral ceiling for another 3 ft up, capped by the flat ceiling and a 4' high crawl space attic. Essentially the second floor looks like a rectangle with the upper corners knocked off, and every surface but the top and bottom is exterior facing. So the sloped ceilings are the thickness of the lathe and plaster, the rafters, and the roof.

Asked By Terry Sharpe | Feb 24 17
4 Answers

How to insulate a shipping container home?

I would like to understand how to best insulate a shipping container home. i am thinking of building on a pier system.

Specifically I am wondering about the double sided foil such as Radiant guard that comes in both permeable and vapor barrier. Which do I put on the inside and which goes on the outside. I live in the Seattle area Marine Zone 4-5.

Asked By SirKoda | Feb 24 17
4 Answers

Follow up question re: basement subfloor (climate zone 7a)

A couple of weeks ago I asked a variety of questions pertaining to my livable space basement retrofit for a 1974 home in climate zone 7a. Recap: there is no exterior foundation or under slab insulation, etc. No water penetration issues into the interior but part of the basement has shown recurring efflorescence and some spalling in a few places.

Asked By user-6759891 | Feb 24 17
Register for a free account and join the conversation


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