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!

1 Answer

Do I need a product like Hydrogap between the basement wall and the foam board insulation?

Mystic CT NZE house. I am applying a foil faced polyiso board (2.5") on concrete basement walls. Do I need a product like Obdyke Hydrogap between the basement wall and the foam board insulation?

Asked By Courtney McCracken | May 11 17
20 Answers

Properly installed can light vs. surface mount

I am doing more research in lighting after an earlier question and reading other articles. The general consensus I am seeing is: Can lights are evil. The logic? Because of air leakage.

Asked By Nicholas C | May 1 17
8 Answers

How to spec high performance windows?

So I've done quite a bit of reading on windows. I'm finishing up the details of a high performance home build in Ottawa, Ontario (Zone 6a/7a equivalent), and need to get my window performance nailed down before I can have a Manual J completed.

Asked By Lance Peters | May 9 17
2 Answers

Horizontal steel siding on house

We are going to be applying 6" of polyiso foam to the outside of our house. It will likely be 3 layers of 2" material. I have concerns related to the potential waviness of the siding plane. The steel siding, applied horizontally, seems to be very unforgiving. Has anyone tried this? And with what success?

Asked By Steve Young | May 10 17
14 Answers

Hot water tank under basement floor?

I have been planning on putting a water tank under the basement of a construction house in Zone 6B. The purpose is to give me a versatile way to store heat.

The heat could come from many sources including capturing the heat from waste water, active, or batch solar hot water, or a heat exchanger on the Masonry wood stove.

The heat could be used to temper the cold water before it enters the hot water heater, heat floors, or preheat EVR air.

All of this is for future use. I just think it makes sense to put it under the floor since it is doable.

Asked By Jim Sweazey | May 9 17
1 Answer

What is a good and resilient approach to weatherizing a log home?

I recently audited a log home in central Vermont (climate zone 6). Unsurprisingly, it was really very leaky (19ACH50). The client is willing to go fairly deep with regards to weatherizing the home, and we both agreed that a reasonable approach seemed to be building a 2x wall inboard of the existing logs and filling the stud bays, including a varied amount of space behind the new stud wall. I would prefer to hold the new stud wall at least an inch off the logs, if the lose of interior space would be acceptable.

Asked By David Bailey | May 9 17
5 Answers

Foundation planning for a self-supporting porch

I am curious as to how a pro would design a basement foundation to allow for the addition of a shed roof (porch or carport). I have significant snow loads in my area (90#) and I think it makes the most sense for the structure to be self-supporting rather than be dependent on a ledger board. Regarding the adjacent basement walls and foundation, does anyone have a suggestion as to what the most prudent approach would be when pouring the foundation and walls? I know the backfill around the house will be considered "disturbed soil" so I am curious to hear what might a good approach.

Asked By John Brown | May 9 17
12 Answers

I would like to ask some questions about attic insulation in a place with very mild weather

Our house was built in 1907 in the South Park neighborhood in San Diego. It is a two story Foursquare Craftsman with 3200 square feet of living space. The home is located right under the landing path of airplanes going to the San Diego Airport which as the crow flies is 3 miles from our home. We have two major problems, no insulation and too much noise.

Our house is located in IECC 2009 Climate Zone 3 a place with very mild weather.

San Diego weather between 2010 and 2016 had:
zero days below 32 degrees Fahrenheit
number of days when temperatures reached at least 70 degrees F:

Asked By Leda Felicio | May 8 17
1 Answer

What is the best housewrap and/or insulation to use with rainscreen and siding?

I live in a 200 year old log home that currently has wood siding that needs replaced. I am going to replace the siding with Boral Truexterior beveled lap siding which is a coal ash composite. I am also going to install Stuc-o-flex Waterway 7mm rain screen.

The house had problems venting with the current ship lap siding. Since I am removing the siding from the log I am considering also adding a house wrap and/or insulation.

Asked By SDaws | May 9 17
5 Answers

Cathedral ceiling rebuild

i live in whistler, canada (zone 6, tons of snow) in a 1970 cabin with recurrent ice damming issues.
we have 3 simple 12/12-pitch shed roofs (no valleys or hips) with no overhangs which i plan to rebuild from the outside (i'm a handy homeowner).

i have thoroughly read and understand all the pertinent articles on this site, and others.
i'm hoping for some feedback to make sure i don't waste time/money/materials, but cost and simplicity are priorities.

Asked By Clark Lewis | May 8 17
Register for a free account and join the conversation

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