Community: GBA Pro help

[Click map to enlarge]

Please register for a free account or sign in to ask and answer green building questions.

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!


7 Answers

Can blown-in fiberglass insulation escape through vents of metal roofs?

We have had fiberglass insulation contaminate our house. We know it entered through the air vent for the furnace and through poorly installed air vents to the house. We are in process of clean up so we can return to the house. I am still worried about the fiberglass insulation because I have had such a violent reaction to it. Is it possible for the insulation to escape out of the vent openings for the metal roof? All possible openings inside the house has been plugged, but am wondering about outside the house.

Asked By Viki Hymer | Oct 24 13
3 Answers

Renovating and installing new cement board

Installing new cement board. Insulation is 1/2-inch blue XPS.
Barriers go under insulation or over? Hardie / CertainTeed contradict each other.
Also, can I get certain types of material that I should use?
I'm in Foxboro, Mass.
1/2" XPS is due to 3/4-inch window allowance, with getting into additional trim thickness.
Tape all seams in insulation and in barrier?
Thanks.

Asked By Steve Rossi | Oct 23 13
1 Answer

Is it possible to install an ERV in a window?

We re-painted the finished attic in our home when we bought the house and for some reason, it has been off-gassing for over 10 months now. My son reacts to it, so we need to do something. It is inefficient to keep a window cracked at all times. We cannot go to the expense at the moment of ducting an ERV into our current HVAC system. Do they make units that can be installed in a window? Thanks.

Asked By Jas Thurber | Oct 21 13
6 Answers

Concrete admixture for waterproofing?

Hello,
We are remodeling and converting some of the garage to living space. We are replacing the foundation stem walls and slab. We had some musty odors in the first floor of the home before starting the remodel, and want to be sure to mitigate any future issues (1 1/2 of the walls are below grade, the slab is at grade (hillside lot)

Asked By R W | Oct 17 13
2 Answers

Kneewall insulation question

I have been diligently air sealing the home we are building. Extreme air sealing probably, but that’s ok – the only time it is taking is mine and I don’t really cost me any money.

I am getting much closer to actually insulating the home with dense-packed cellulose behind a smart membrane (Intello Plus, in this case) and I have a few questions about some tricky areas. I’ve got some photos and will try to explain the situation adequately.

Asked By Lucy Foxworth | Oct 16 13
4 Answers

Open cell vs closed cell

I am renovating my daughter's room located on the second floor of the house. I got a estimate from a spray foam company. They recommended 6 inch open cell in between my ceiling 2x8 rafters. On the west side exterior wall with a brick wall in the center of the wood frame (chimney) they want to apply 3 inch closed spray foam in 2x4 wall. I believe I am in zone 4a. My question is: is the open cell the right product and do I need a vapor barrier?

Asked By SAMUEL FILINCIERI | Oct 7 13
5 Answers

Exterior siding details

My house is a 1500 square ft bungalow located on Lake of the Woods in Ontario near the Minnesota border (Climate Zone 7) . Before I purchased the house the previous owners replaced all the windows with triple pane pane windows but had the installers build them out 1.5" with intentions of adding exterior foam when the siding was to be replaced. I have since gutted the entire main floor and rewired, plumbed and insulated with 3.5" of closed cell spray foam in the walls. I added a couple more windows and a set of patio doors and stuck with the 1.5" build out.

Asked By JP Patrick | Oct 2 13
3 Answers

Fiberglass-clad sheetrock as vapor retarder?

Hi,
I live in IRC zone 5A Pennsylvania. I’m insulating the walls of my kitchen; it was gutted to redo the wiring and the plumbing. There are two exterior walls a north and south side an uninsulated garage on the east side and the main house on the west side.
The exterior walls are clad with vinyl siding over house wrap. The corners of the kitchen are sheathed with ¾ inch plywood –the rest is clad with ¾ polyisocyanurate (PIR). The framing is 2x6, 16 inches OC.

Asked By Anthony Jackson | Oct 1 13
1 Answer

Pre-existing unvented cathedral ceiling-- will there be problems?

My client has a house built in the 1970s with cathedral ceilings, a shallow (2 in 12) roof, 2x12 rafters, and T&G pine ceiling. The ceiling was insulated (looks like R-38 faced batts), but there is neither ridge nor soffet venting. The owner had a membrane roof put on about 2 years ago and now wants to remodel. I am concerned about an unvented roof with a relatively "leaky" ceiling-- won't there be issues with moist air getting into rafter space and condensing on the underside of the roof deck?

Asked By cynthia sharon | Sep 25 13
3 Answers

Cathedral ceiling technique explained?

Hello,

I posted a full description in the insulation and energy forum, but I am also looking for the building details for the unvented cathedral as seen on page 68 of the article posted below. The #3 Unvented roof. We are in the SF Bay area.

My roof has 6x10 beams, covered by 1 1/2" T&G. In the re roof, this will get sheathed with plywood, then I'll add two to three layers of 2" polyiso. I am hoping for 2 layers to save money. Will that give me a true R30? I thought it was only R 6.5 per inch. On top of that will be another layer of 1/2 ply.

Asked By R W | Sep 22 13
Register for a free account and join the conversation


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