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!

9 Answers

Building a furnace room in the attic

What is the best way to build a furnace room in the attic?

How big should the framing be? 2x6s? Also, should I attach plywood to the framing or just nail polyisoprene directly to framing? How many layers of R13 Polyiso? Is it better to do 1 layer of foil faced polyisoprene on the inside of the framing and then just put fiberglass batts on the outside?

Thanks a lot?

In General questions | Asked By BuildingNewb | Dec 6 17
1 Answer

Does traditional plaster serve as a sufficient air seal between living space and attic in an older home?

We're restoring an older balloon-frame structure (1890s) in a northern Gulf Coast climate (extreme humidity, some heating load, large cooling load). Fortunately, we've been able to design the house's first ever HVAC system so that all the ductwork and mechanicals are located in a fairly short run down the long central hall -- within the conditioned space, and just beneath the existing ceiling plane (a false drywall ceiling will sit a foot or so below the old ceiling). The existing ceiling over most of the house is a rather thick plaster (with surprisingly few visible cracks).

In Energy efficiency and durability | Asked By user-6970120 | Dec 9 17
19 Answers

Insulating Basement - Southern Part of Climate Zone 4

I live in Northwest Arkansas, Climate Zone 4 not far from the climate Zone 3 border. Most people don't have basements around here, so no one seems to know what's best for this climate.

In Energy efficiency and durability | Asked By Arkansas67 | Dec 4 17
2 Answers

Basement insulation for concrete party wall

Hi All,
I'm noobie DIYer as far as framing and finishing basements go, trying to start a project to finish my 500 sq. ft. basement in southeast Pennsylvania. I'm in a end unit town home, so the basement has poured concrete external walls on 3 sides, and a concrete party wall shared with my neighbor. Need advice and confirmation on my insulation plans, any help would be appreciated!

In General questions | Asked By Phillydude | Dec 9 17
4 Answers

Any way to predict aquaponics impact on basement humidity?

Hey guys, I need some help from my smarter friends.

Is there any way to crunch some numbers and calculate what kind of impact a small aquaponics project would be on my basement humidity?

In General questions | Asked By Clay Whitenack | Dec 8 17
2 Answers

Should I vent my polyiso insulation?

I have put down my roof, except for the top roofing membrane.

Here is my roof assembly:

9.5" Joists with R31 Glasswool Batting
3/4" T&G plywood decking
Roofing underlay (IKO Armourguard Ice and water sheild)
3" + 3" Polyiso Insulation, R 34, staggered Joints, joints filled with closed cell foam.
1/8" asphalt protection top board, seams caulked.
(Not done yet) Polyurethane liquid applied roof membrane.
(TBD) 2.5" Live vegetative roof assembly.

In General questions | Asked By Jamie B | Dec 8 17
10 Answers

Does sealing rim joists slow the flow of air into attic?

Will sealing the rim joists in my basement significantly slow the stack effect or will the house just begin to pull its makeup air from other areas in the house instead?

Similarly, would sealing gaps from inside the house also slow the stack effect such as around hvac registers, ceiling fixtures, outlet boxes etc?

Due to the difficult layout of my attic with ductwork everywhere, I'm trying to do as much as I can from the accessible portions of my home.

In Energy efficiency and durability | Asked By BuildingNewb | Dec 6 17
10 Answers

Painting old wood siding?

I'm looking to remove the vinyl siding from my house and either paint the old wood clapboard siding or remove it and replace with it LP, Hardie, or cedar - or maybe Boral polyash. Still doing the research on which siding to use. I've removed a small section of vinyl and the old siding is in pretty good shape but I've been told I'll regret leaving the old wood because paint will never stick to it. Blown in cellulose has been installed directly behind the clapboards and I've heard that also reduces the life of the paint. Thoughts?

In General questions | Asked By Michael Mohr | Nov 28 17
5 Answers

Retrofit flood-resistant wall assembly

Proposed Wall Details:
- 2x4 treated bottom plate, untreated 2x4 framing, 1/2" exterior plywood sheathing covered with building paper and Hardi Plank siding on the exterior (No rain screed).
- Bottom of stud cavity (First 12" to 18") insulated with closed cell spay foam, the balance of the wall insulated with fiberglass of rock wool.
- Bottom ( First 12" to 18") of interior finished with PVC wainscoting or other waterproof material. the balance of the interior wall finished with 1/2" drywall..

In Energy efficiency and durability | Asked By Anthony Swoope | Dec 8 17
24 Answers

Marine Zone 4 — Wall insulation — addition

Zone: Marine 4
Location: Seattle, WA
House Built: 1915
Square footage: 900 ft2 single story with 900 ft2 finished basement.
Wall height over basement: 12 ft
Current siding: Cedar, Paint in poor condition.
Insulation: not much, some fiberglass bat stuffed in nooks and crannies as they opened walls in the past. And dirty so there is plenty of air gaps.

GOAL: Comfort

In Plans Review | Asked By User-6933356 | Oct 11 17
Register for a free account and join the conversation

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