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!


3 Answers

Curious what the best way is to retrofit (air/vapor seal) my home to make it more durable & energy efficient

I have a ranch style home with a walk-out basement on a poured concrete foundation. It is framed with 2x4 walls, fiberglass batt insulation, OSB exterior sheathing, standard housewrap, floor/roof trusses, tar paper on roof and shingles. The basement is finished. It's a pretty standard house. I want to get the most bang for my buck without tearing down and rebuilding. I am in Virginia, climate zone 4. What would be the best way to go about doing this?

In General questions | Asked By Spencer Shemwell | Feb 10 17
4 Answers

When to try and when to fly

I live in 1300 sq ft 2 story home built in 1908 in NW PA. We did some renovation in 2008 but mainly focused on inside finish and trim. I'm very focused on energy efficiency and green living. My thought was to go forward and apply know green renovation techniques to this house ( insulation, air sealing, better mechanicals, etc.) However, I'm afraid that this work is pushing beyond what this home's value is. I really believe in what Martin said about the greenest homes are the ones that already exists.

In General questions | Asked By Armando Reyes | Feb 10 17
2 Answers

Insulating Basement/Crawlspace... among other things

My house was built in the late 1800's and is in climate zone 4C in Oregon. It has about a total footprint of 660 sq ft and is half basement/half crawlspace with a cripple wall all along the perimeter. Both basement and crawlspace are unconditioned with no venting. The grade slopes toward the house from the backyard. I'd say in the backyard the grade is half way up the 19" high cripple wall and in the front yard grade is 8" below the top of the concrete foundation.

In Energy efficiency and durability | Asked By CurryRojo | Feb 9 17
2 Answers

Salvaged ash lumber? - Emerald ash borer damaged trees

Last year I promised some pictures of Emerald Ash Borer tree damage; I recently stumbled upon the images I had selected, but never posted.

Attached are images of the insect damage on a log and standing tree. Also an image of one of the clues that an ash tree is in trouble, marks from pileated woodpeckers hammering away at it.

Ash doesn't come to mind as a common building product. However, with such significant numbers of ash trees now standing dead, maybe that will change?

(Probably will be hard to get a decent baseball bat down the road...)

In Green products and materials | Asked By Andrew Bater | Feb 9 17
1 Answer

Metal roof over unvented cathedral ceiling

Seeking advice on this application.

Center of home is Unvented Cathedral Ceiling with Closed Cell (possibly flash and batt to reach R value). On top of the sheathing will be asphalt felt, then metal roof. We purchased the Classic Rib from Metal Sales.

Sides of the home are Vented Attics with fiberglass insulation. Also to have asphalt felt on top of the sheathing, then metal roof.

I called Metal Sales, and they stated the metal roof can be installed directly to the underlayment.
Does anyone see any possible condensation issues?

Climate Zone 5.

In Energy efficiency and durability | Asked By Bridget Lamberson | Feb 9 17
5 Answers

Heat-pump water heater for an all-electric garage apartment?

We our building a detached garage w/ 2nd story apartment (1 bedroom, ~900 sq ft conditioned space) & debating the system to heat water:
- Primary purpose for the garage apartment is for our mothers to live in as they age. Mainly for safety reasons, we're not having gas service to the apartment (could do relatively easily - main house has gas service)
- Cooling-dominated climate (Houston TX)

In Mechanicals | Asked By Robert Hallenbeck | Feb 8 17
4 Answers

Exterior stain residual

I am converting my barn and some of what was the exterior surface will be within the insulated wall assembly. This surface was stained by the previous owner last spring with a exterior deck stain TWP 1500. Wondering if I should be concerned about some residue of the pReservative being in my wall assembly. Not sure how I could get it off othe than planning the exterior or something like that. Or perhaps pressure washing would remove a bit of it. Any one have any thoughts... Thanks

In Green products and materials | Asked By scott mangold | Feb 9 17
7 Answers

Advice on my wall assembly

Hello, I'm getting ready to build a new home in western North Carolina. I would appreciate advice on my proposed wall assembly. 2x4 walls with huber's R-Zip 9.6 (2" thick overall) and coravent studi battens for a rain screen assembly. The idea is to end up with a wall assembly thickness so I can order windows for a 2x6 wall and have them work. So I end up with drywall(1/2") + 2x4 wall (3 1/2")+ Rzip board (2") + sturdi batten coravent (7/16") = 6 7/16". I was planning on closed cell foam in the 2x4 wall cavity.

Does this seem like a reasonable assembly?

In Energy efficiency and durability | Asked By Jeffrey Higel | Feb 8 17
8 Answers

HRV for wet room exhaust: Will I have to build a motorized damper box myself?

I currently own a 2006 Lifebreath HRV 155cfm unit in SouthWestern Ontario. It was ducted well enough, but it basically pulls from too many areas of the house (kitchen, laundry room, 3 bathrooms). It does a good job of whole house ventilation, but basically it feels underpowered for wet room exhaust (1850sqft 2 story, with unit in basement, so some runs are also quite long, all flex).

In Mechanicals | Asked By Mai Tai | Feb 8 17
2 Answers

What insulation for band joists between floors?

Hi all,

We have a super-insulated home in zone 4a. 3" of polyiso on the outside, then damp blown cellulose between 2x6 studs, 16"oc.

What do people use to insulate in the band joists between the 1st and 2nd floor? The concern I had about using blown cellulose there is whether the cellulose would stay firmly in place over time. In the walls, you have the drywall keeping it from crumbling out too much. However, there wouldn't be anything holding in the insulation in the band joists.

In Green building techniques | Asked By Clay Whitenack | Feb 9 17
Register for a free account and join the conversation


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