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!

8 Answers

Basement insulation...pull the XPS?

Long story short, between work and family obligations I've been busting my tail to get my basement walls insulated and studded in preparation for finishing it off. Had an inspector come through only to hear that he considers the 2" xps I installed behind the stud walls to be a prohibited vapor barrier. Mind you I took extra caution to put in nice tight seams, tape the seams with that special red foam tape, and caulk around the perimeters AND I put up and secured the stud walls in front of the xps.

In Building Code Questions | Asked By Will Golden | Mar 24 16
3 Answers

Has anyone used Imetco Intelliscreen, especially on a residential retrofit?

Hi all,

I'm looking for a retrofit solution to a poor siding choice on a residential addition. The addition was made some 30 years ago and used 3/8" masonite type product as sheathing and siding (it's not T-111). It was then coated with a faux stucco paint. The seams were not covered (ie not board and batten style). Honestly, it is remarkable how well it has stood the test of time.

I'm investigating options either replacing (or more likely simply covering) the 'sheathing'. For engineering reasons (penthouse style), matching the remainder of the home's stucco is undesirable.

In Green products and materials | Asked By Keith H | Mar 25 16
2 Answers

Rigid foam over exterior stucco?

I would like add insulation to the walls of an addition to our mostly brick house in Climate Zone 4a. As best as I can tell, the walls in the later addition to the house have stucco on the exterior, I have no idea about insulation between studs and water barriers in others layers. Because of built in bookcases on the inside of the walls it would be hard to add insulation in the interior, so I was thinking of adding exterior insulation with rigid foam, but I am concerned about a moisture trap if I were to add that straight as an extra layer over the existing stucco on the outside.

In General questions | Asked By matthias paustian | Mar 25 16
2 Answers

HVAC, hot water, pool heat dump, combination supplier?

I am building a new home for myself that I am trying to make as
efficient as possible , the home will be in Cave Creek , Arizona , in the
summer it reaches up around 115 degrees . The home itself will have approx.
3700sqft liveable , will have a swimming pool ( approx. 800sqft ) approx. 9ft deepest ,
there will also be a Jacuzzi , the pool will be a natural one ( no chemicals ) and will
have a constant flow of water through plants and a waterfall , additional
sprays can be used at night to aid cooling , I will also have solar

In Mechanicals | Asked By David Lowe | Mar 24 16
2 Answers

Is there a system that uses 2" polyiso for the wall and 3" for the roof that could be considered energy efficient for zone 6?

Is there a way to construct an energy efficient home for Northern Vermont using 2" polyiso walls and 3" in the roof? There are 3/4" t+g pine boards on the interior, an aluminum vapor barrier, polyiso, stapping and clapboards. How does this work in zone six? Am I missing something?

In Energy efficiency and durability | Asked By Luke Thompson | Mar 24 16
1 Answer

Do I need to worry about kitchen cabinets creating vapor trap?

I have 2" of faced EPS on the exterior of my walls. Will installing kitchen cabinets on an exterior wall in the conventional fashion create a moisture trap? The cabinet supplier is going to measure in the next couple days and then order cabinets. If I need to back-ventilate the cabinets, I need to specify that now so they can account for it.

In Energy efficiency and durability | Asked By Reid Baldwin | Mar 25 16
2 Answers

Certification for re-purposed polyiso. Manufacturer is unkown

The Farifax County code in which I live is as follows:

N1101.12.1 (R303.1.1) Building thermal envelope insulation.

In Building Code Questions | Asked By frost patrick | Mar 24 16
8 Answers

To foam or not to foam? — Basement insulation help desperately needed

I have been actively researching this topic for quite some time, and I feel that every time I finally determine the "proper" way to do it, another piece of contradictory information pops up. I am trying to determine correct method to insulate my basement walls. My home was built in 2007, and there is currently 2" of XPS surround exterior of basement. All of basement walls are below grade. Going to be framing with 2x4 studs. I believe that I should be aiming for R20 total? Is that right? 15/19?

In Energy efficiency and durability | Asked By Trace | Jan 13 16
3 Answers

Does anyone have experience using an electric boiler with integrated instantaneous water heater?

We are considering the Combomax Ultra 12, which is designed to supply all the hot water required for hydronic space heating and domestic hot water (see http://www.thermo2000.com/content/en-us/s2_produits/combomax-ultra.aspx#). I haven't been able to find any reviews on-line and would be very interested in views of pros and/or home owners who have experience with this product or even a similar combo product. Thanks for any information or advice you might be able to share with me!

In Energy efficiency and durability | Asked By Barbara Secker | Mar 23 16
6 Answers

Need advice on closing in porch

My house is in the SE Texas Panhandle, in zone 3B, but only 15 miles from Oklahoma (zone 3A) and also only 15 miles from the majority of the panhandle (zone 4B). So we have a very mixed climate that in my lifetime I have seen range from -15 degrees to +115 degrees F. Some years it is quite dry and some years quite rainy and humid.

In General questions | Asked By Linda Wolf | Mar 21 16
Register for a free account and join the conversation

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