Q&A: A Forum for Green Building Experts and Beginners

[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!


24 Answers

Solar panels for electricity generation

I would like to decide on putting in solar panels to reduce energy costs.

I have read about the next generation solar panels not being to far off.

Question: Would it be better to install current solar panels or wait for the new type that will be coming shortly?

In Green products and materials | Asked By John Alberti | Aug 26 14
0 Answers

I am considering using Boral TruExterior trim on a new house in lieu of Azek board

I am considering using Boral TruExterior trim on a new house in lieu of Azek board. I have been told that the product offers equivalent performance for less money.

Anybody have any opinions regarding this product?
Thanks.

In Green products and materials | Asked By Chuck Plaisted | Sep 3 14
3 Answers

Where is the link to the free webinar about basement insulation on Sept 4?

Where is the link to the free webinar about basement insulation on Sept 4?

In General questions | Asked By Lowell Lo | Sep 3 14
6 Answers

Finishing rigid foam against an innie window

So I read the innie vs. outie window article on GBA and decided to go with the innie route as I had already made my R/O to size and didn't have time to fir out the windows before my window installer (friend) showed up. So I have my windows in with flanges against sheathing and they stick out just over 2" from the sheathing. I am putting 2' rigid polyiso on the exterior and butting it into the windows. This means there is no foam showing. Do I need to put peel and stick flashing on the exposed foam before installing it? should I leave it away from the window slightly and spray foam that gap?

In Green building techniques | Asked By jordan Saunders | Sep 1 14
19 Answers

Spray foaming the attic with a twist

I will be having my attic sealed and insulated with closed-cell spray foam. However, the design of my house makes this a bit more complicated because my roof cuts into the second-story ceilings at the front and rear edges of the house (will make more sense if you look at the attached pic).

Above this part of the ceiling, there is only some very old batt insulation (less than R-8) and the roof deck. The house doesn't have eaves/soffits, so there is no venting in this area.

In Energy efficiency and durability | Asked By Matt Culik | Aug 14 14
25 Answers

Subsurface rigid insulation and boring critters

I was speaking with my passive house consultant the other week, and she expressed concerns about boring critters and subsurface rigid insulation. She had such an experience with some insulation in her garden (It was put in one season and removed at a later time as she got back to completing the project.)
Now, I know all about the ate/termite protection used in these insulation products, but what about larger critters that would love to have a warm dry home?

In General questions | Asked By Steve Young | Aug 16 14
20 Answers

XPS versus EPS Underslab Foam

Hi. I am back and forth on whether I should use XPS (blue board) or EPS for the insulation underneath my slab. I understand the qualities of each regarding water absorption and drying out, but would it (XPS particularly) affect the long term performance to the point where the slab is compromised? I also understand the pollution associated with XPS manufacturing. I have the option of purchasing 6" (house in very cold climate) of EPS (R-24) or 4" of XPS (R-20). The EPS is less expensive per inch, however, I need to pay for shipping which jacks up the price.

In Energy efficiency and durability | Asked By Matthew Michaud | May 2 14
3 Answers

Rigid insulation between interior bearing wall footings and slab?

We're building a new 2-story home in central Iowa. It will have a below grade basement with 9' foundation walls. The slab will be about 8 feet below grade.

In Green building techniques | Asked By Silas Hoeppner | Sep 1 14
10 Answers

XPS vs. polyisocyanurate

Hi,
I am currently redoing the exterior of my house with a new vinyl siding and changing all windows. My house was built in the mid 80's and have 2x6 studs with Batt Insulation and mostly without a vapor barrier... but the insulation is not great, especially the air goes through the house.
My question is what is the best insulation for me to put outside the house underneath the vinyl siding. My windows will allow me to go up to 1 inches of exterior insulation.
So XPS with Typar? Polyisocyanurate (IKO Ener Air )? Others?

In Energy efficiency and durability | Asked By Jason Haché | Aug 29 14
4 Answers

Unvented vs. vented roof

Hello,
I live in the Pacific north west, and will be building a home off the cost of Vancouver island this fall. The house is small, 700 square feet, with a 1 n 12 pitched roof as the design. We have not started construction on the house as yet and we want to deal with the roof in a way that will, of course, provide the best of all worlds.

In General questions | Asked By Jeannette Sirois | Sep 1 14
Register for a free account and join the conversation


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