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!


0 Answers

Line set hides on clapboard or shingle siding

I have to mount 18K BTU AC-only line sets at two locations on Certainteed/Vytec simulated polymer cedar split shake called Cedar Impressions or Rough Split Shakes.

http://www.certainteed.com/resources/CTS100.pdf

In General questions | Asked By flitch plate | Sep 11 15
6 Answers

How efficient are horizontal axis washing machines? Really?

Since 2002 I have had 2 different high efficiency washing machines. The first failed within warranty and was repaired for free and at 7 years of age failed catastrophically. I got a new one and now it needs repair. These are high tech machines and I can't fix them myself. I am considering buying an old fashioned "new" , belt drive, mechanical timer, commercial, Maytag.

In Mechanicals | Asked By Steven McCarthy | Sep 9 15
3 Answers

Best way to suspend a ceiling for service cavity under air barrier?

I'm working on a single story house design. I would like to make a continuous taped osb (Zip likely) air barrier on the bottom side of the roof truss under my insulation. I would like to suspend the drywall 6+ inches below the air barrier to make a service cavity for sewer vents, ducts, and recessed lights. What would be the most economical way to construct this?

A couple ideas came to mind:

A: 2x lumber somehow attached to the trusses.

B: Ceiling joists supported by the interior walls.

C: Wide steel studs screwed to the trusses.

D: z-furring screwed to the trusses.

In Green building techniques | Asked By John Ranson | Sep 9 15
3 Answers

In a building more than 3 floors, is it better to use header design for top sills or just use(4) 2x4 stacked w/ concrete floors?

We have had some major settling in our builds where the framer and engineer have used (4) 2x4's stack flat as there top sills between each floor of the building which is 6 stories tall on one side and 5 stories on the other, we have had more then 1 1/2 inches in settling in just 9 months and it is causing the plumbing tees to brake in the laundry rooms.

In Building Code Questions | Asked By Andrew Taranto | Sep 9 15
2 Answers

Using foam sheathing inside and outside a block wall

I am insulating (half way there) inside a concrete block barn I am renovating with 2" EPS. This hides all the electrical conduit and boxes, I thought it very smart. I was planning to insulate the exterior with 1 1/2 " rigid foam to get code R value, put strapping on that and then vertical wood siding. I see here on GPA where this will trap moisture that may collect between the foam and block.

In Green building techniques | Asked By Philip Faucher | Sep 9 15
1 Answer

Smoke puffer for blower door testing?

I used to buy TiCl4 smoke puffers (okay, maybe not such a green product but a little TiCl4 never hurt anybody, it's the HCl that forms in your lungs when you breath it in that's the problem) from Zerodraft in Toronto for less than $100 including shipping. Now they only seem to be available from Retrotec and the shipping is outlandish (not Retrotec's fault, they are now considered a hazardous material) and I haven't bothered to find out how much it would be to ship to Canada.

In Green products and materials | Asked By David Baerg | Sep 9 15
7 Answers

Installed 3' polyiso in my basement (Zone 5a) and humidity is now at 50%

Hi all,
So the background, we have a 1400sq ft basement , I have used XPS 3' to seal the rim joists with spray foam for the edges
The rest of the basement is straight concrete, it is 8ft tall with 6ft under grade, the concrete has been given a water proof membrane when the house was built.
I am 3/4 of the way through installing the poly iso 3" gluing them to the walls, sealing the seams with 3" tape and sealing the edges with a bead of spray foam to seal everything air tight
The issue is my humidity is now gone up to 49% and it feels humid when you descend the stairs

In Green building techniques | Asked By Darren Finch | Sep 9 15
4 Answers

Old home, half-story insulation

I'm in Maine. I've got an old 1.5 story farm house, built in the 1860s. We have done a lot of work to the downstairs, but this is our first time working on any of the rooms upstairs.

The room I'm working on is part of a newer (but but still quite old) addition.
Here's a photo of what we have after removing floor/wall/ceiling covering

In Energy efficiency and durability | Asked By Eric B | Sep 9 15
5 Answers

9' or 10' ceiling for mixed humid climate - Zone 4A?

Trying to decide on the best ceiling height for the first floor... 9' or 10'. I realize 10' ceiling heights are more expensive from a construction standpoint (more lumber, more labor to cut the lumber since no 10' studs, more drywall, more insulation, more siding, etc.), but what about the HVAC loads? It would obviously cost more to heat, since heat rises, but how much more? Considerably more or just marginally? I assume it would be cooler in the summer for the same reason? All the older houses around here (before the invention of AC) had 10'+ ceilings as a way to help keep cool.

In Energy efficiency and durability | Asked By Clay Whitenack | Sep 9 15
1 Answer

Why can't I save the information I've found on your site?

I found an article on vermiculite in an attic and I want to print it for my client... How do I accomplish this?

In Green building techniques | Asked By Myrna Walker | Sep 9 15
Register for a free account and join the conversation


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