Community: GBA Pro help

Q & A Instructions

[Click map to enlarge]

The 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!

2 Answers

How do I properly use Azek sheet goods as exterior trim?

Three years ago I had my 90 year old house redone. Recently we discovered a leaking door in an addition that was built onto the house. The addition was timber framed 16" on center using 1/2 inch exterior grade plywood as sheathing. 6 inches of spray foam insulation was used on all exterior walls the interior was finished with 1/2" drywall. Exterior walls were wrapped with Tyvek and 3/8" Azek was nailed to the sheathing seams were glued and perimiter was caulked.

Asked By Lawrence Reich | Jun 11 14
1 Answer

Below grade polyethylene and slab

I am questioning as to the order of polyethylene vapor barrier to foam when placed under a slab. The reason I ask is because I am currently having my house built and today I have discovered that the contractor placed the poly directly on the ground (good drainable material) with the blue board foam boards on top of it. I have read in the past that the poly should be placed on top. I am worried that it has been done incorrectly. Any thoughts to put my mind at ease as I am rather stressed out right now. Thanks in advance.

Asked By Matthew Michaud | Jun 5 14
42 Answers

Dense Packing Slopes with 11.25 " rafters. Bad idea?

I did a lot of research when I built. Bottom line is that I chose the cheaper easier method and now I'm paying for it. I continue to hear that it's OK to dense pack cellulose in a slope and not vent it or not flash it with closed cell foam. This is incorrect and I can prove it now! Moisture has collected on the back side of the roof sheeting and ice chunks have formed, mostly on the north side of the house. Any where there's snow build up on the south side I have ice formation on the inside of the roof sheathing as well.

Asked By James ODonnell | Mar 4 14
0 Answers

Fix a water leak between porch and house

I have a poured concrete porch that also serves as a roof for a basement storage room. When the builder proposed creating this space, I had reservations but he "did them all the time and they never leaked." Even so, I asked the him to include a roofing membrane that would extend from the house wrap (spanning the joint between the slab and house) and under the slab out to its edge. I thought the sub had completed this step, but it's now apparent that he did not. I now have a slow drip into the storage room whenever it rains.

Asked By Steve Knapp | May 19 14
2 Answers

When Cellulose Insulation is subjected to moisture or disturbed after being blown in, how is it affected?

We hired a contractor in Canada to replace insulation in our attic when a roof patch opened up under an ice dam in 2011. They removed batt insulation and replaced it with blown in cellulose fibre insulation. When they blew in cellulose insulation they did not connect the new bathroom vent hoses they supplied or seal pot lights below the vapour barrier and this is an extreme winter weather climate. This spring, the insulation was disturbed in order to determine the source of water causing damage to the drywall in the room beneath this space.

Asked By Susan Bly | May 19 14
9 Answers

Poor attic ventilation, a.k.a. mold on rafters

Hello all,
Here are the basic details:

- I have a 23 year old 2-story frame house in the mid-Atlantic region (Zone 5). The roof was replaced last year, and there is a ridge vent, soffit vents at intervals and baffles inside the attic to allow unimpeded air flow into the attic.
- The bathroom exhaust fans are vented off to side camp vent on the side off the house. Though the fans seem to be running, I have a serious suspicion that they aren't actually pulling in anything.

Asked By Kach Kidibba | Apr 23 14
8 Answers

Need consultant expert on residential ERV/HRV air balancing

I live in northern VA suburbs. My residential HVAC system includes a LifeBreath ERV, which has been installed for 5 yrs. During that time, I have had contracts with 3 different HVAC service companies. NONE of them have been able to keep my ERV exhaust & intake air flows balanced.

Asked By Terry Sopher Sr | May 14 14
2 Answers

ERV for a basement apartment

We are renovating a 900 sq. foot basement apartment in Beacon, NY (Hudson Valley - area code 12508). It's partly below grade, and pretty tight with new double pane windows.

We're thinking of putting in an ERV for ventilation since:
1) We think that having the availability of ventilation in the basement apartment is a good thing.
2) We've noticed a slight mustiness in there.

Asked By Yaakov Weintraub | May 15 14
2 Answers

Daily attic air exchanges?

.. with a balanced attic ventilation system in place,

how many attic air exchanges daily should be expected?

Asked By Hans Mayer | May 5 14
4 Answers

Help — Critters in my windows

I don't know if this is a question you have ever seen before. Recently we decided to remove a window and close the wall up. It was not possible to remove the window intact without damaging the siding, so my husband cut the frame and removed it in pieces. The windows are typical vinyl single-hung windows. They seem like good energy-efficient, double pane windows and are newer.

Asked By L H | Apr 30 14
Register for a free account and join the conversation

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