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9 Answers

Advice regarding adding insulation to log home with added siding

Hi, we have an unusual situation and I just want to make sure I'm not about to do something stupid! We have a log home that was not well-maintained, so we ended up putting board-and-batten siding over two of the walls to try and arrest the further decay of the logs. We couldn't afford to add insulation at the time. We ended up adding house wrap on top of the logs and then the builders put 2x4's horizontally along the logs (although in some places they had to build out further because of unevenness) and applied the siding.

In GBA Pro help | Asked By Debbie Baskerville | Oct 12 15
5 Answers

How do you assess flash-and-batt installations?

We have begun to see more Builders and Insulators use flash and batt installation and I am not sure how to assess the R-value of the installation and if the installation actually meets the intent of code and programs. Let me make the case… First premise it that RESNET grade one installation is equivalent to meeting the intent of the code as the code only say that insulation must be installed in accordance with manufacture instructions.

In Building Code Questions | Asked By Robby Schwarz | Oct 11 15
3 Answers

Vapor barrier on the inside against sheet rock or outside against sheathing or both sides of rock wool?

I'm doing a rehab remodel on a house I recently bought and have the exterior walls exposed on the house. I'm trying to upgrade the existing insulation since I had to replace quite a lot of the framing to repair dry rot. I'm trying to minimize moisture buildup in the wall spaces from both directions as well as effectively insulate the house. Plus, I've been getting clobbered on utilities.

In Energy efficiency and durability | Asked By Ken Swartz | Oct 12 15
0 Answers

Recommendations for a small HRV

Hi everyone
I'm looking to buy an HRV for our small (1000 sqft) ranch home.

I already installed all the dedicated ductwork last year and had been using a home-made HRV that worked very well, but I don't have the time to keep tinkering with it to get it to work just right. The cabinet was made of plywood and I kept having problems with the air streams crossing and causing condensation and mold in the cabinet.
Anyway as a result I'm going to hook up a new HRV to my ductwork.

I'd like a small unit - I will be installing it in a closet
Quiet would be good
Also with ports on top

In Mechanicals | Asked By Carlo Giombi | Oct 12 15
1 Answer


Does anyone know of a SIP manufacturer using a low GWP blowing agent, like Honeywell's Solstice blowing agents?

In Green products and materials | Asked By Steven Gubkin | Oct 11 15
6 Answers

Easiest concealed-fastener metal roofing

Working alone, I will be covering the simple gable roof of my new house with steel panels attached to purlins 2' oc without decking. I would like to use a concealed-fastener system. The Vertical Seam panels made by Metal Sales are approved for open framing, but after reading the installation manual, I have the impression they will be a pain to install, using tons of butyl tape and tube sealant in addition to quite a wide assortment of steel parts, including z-closures that have to be cut and bent on each end by hand for each of the 78 panels I will install.

In Green building techniques | Asked By Jeff Cooper | Oct 11 15
5 Answers

Gree Mini-split heat pumps

I'm hoping Dana will weigh in on this question given his expertise with specifying and analyzing mini-split heat pumps.

There are some new heat pumps on the market from Gree that appear to approach the performance of the best units from Mitsubishi and Fujitsu. It appears to me that the cooling efficiency is right up there with Mitsubishi and Fujitsu, though the heating efficiency isn't as good. They do however specify heating capacity down to -20 degrees F.


In Mechanicals | Asked By Joshua van Tol | Oct 9 15
6 Answers

Dense pack cellulose in sloped ceilings -- need vent chutes?

I have an 1800's story and a half log home. There are knee walls on the 2nd story which have been insulated in a variety of different ways -- but most knee walls are treated as unconditioned space.

An insulation contractor proposed bringing the knee wall floors and the upper attic floors up to R50 by adding more blown in cellulose.

He proposed stuffing the rafter bays in the knee walls and dense packing the sloped bedroom ceilings (connecting the knee wall to the upper attic) with dense pack cellulose.

In Energy efficiency and durability | Asked By Andrew S | Oct 10 15
4 Answers

Insulating a crawlspace

Hi, I have a 70 yr old home built on a post and pad foundation. It is quite leaky and I'm in the earlier stages of fixing it up. I'm currently in the process of removing and replacing the skirting that runs the perimeter as it is unisulated and has enough rot to warrant its replacement. We live in southern coastal British Columbia. Winters here are rainy and only drop below freezing for short periods of time. My plan is to frame between the posts and fill with sheets of 2" xps topped with a rainscreen and cedar siding. The idea is to trap the heated air that escapes under the house.

In Green building techniques | Asked By Michael Blake | Oct 10 15
11 Answers

Moving a gas water heater into the envelope of the home...or switch to electric?

I just acquired a early 90's home and it turns out we can't get our minivans into the garage! On one side we have the HVAC equipment and on the other the water heater (both are gas). The HVAC I think we can relocate to an area of the bonus room directly over the garage so there will be minimal adjustment needed to the duct work. The logical place to relocate the water heater will be just inside on the same wall it is now which is currently a laundry room. I have never had a house with gas units inside the envelope of the home. So....

In Mechanicals | Asked By Andrew Bennett | Oct 9 15
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