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!

2 Answers

Has anyone ran across a design guide for passive solar thermal heating and cooling using water-antifreeze as mass in pex metal radiant roof and/or floor-wall lines? I’m thinking solar thermo-siphon vs a mechanical pump.

Asked By Terry Lee | Sep 1 14
7 Answers

Hello,

My home has return grilles on the wall about 3 ft down from the ceiling on 9 ft walls and about 4 ft down on 14 foot walls on the first floor. In the basement, they are on the wall about a foot up from the floor.

I am planning to install a ERV/HRV to combat elevated humidity in winter; I have had water condense along the ceiling edges and on windows during winter. The ERV/HRV will draw air from the return ducts and dump the fresh air into the basement.

Asked By Venkat Y | Aug 31 14
1 Answer

Lots of information on this website, FHB, BSC, etc about airtight drywall approach.

Maybe I'm overlooking it, but I'm not able to find much on the following topics...

1.) What gaskets or caulk work best?
Martin has suggested polyurethane caulk and several brands of gaskets or sill seal in previous posts. Anyone have a particular brand or type of caulk/gasket/seal that they like best? Any tried the "ripped pieces of closed cell sill seal foam" method?
2.) What kind of results people have had using these techniques?

Asked By Robert Kohaus | Sep 1 14
1 Answer

We have a huge ventless gas log fireplace unit that has never been used, nor is planned to be used. We want to remove it, but do not know what is behind or underneath it, and if it will be costly to repair once removed. What is the proper way to remove this monstrosity?

Asked By Pamela Davidson | Aug 31 14
1 Answer

Hello,

To combat elevated humidity levels in my home, I am planning to connect an HRV to draw air from the HVAC return duct and to then to dump fresh air into the basement. Due to the limited space in the mechanicals/HVAC room, I am planning to install the HRV in the garage, but I see HRV manufacturers want it installed in an operating environment that's at least 50F, so my unheated garage would not be a proper location.

Asked By Venkat Y | Aug 31 14
6 Answers

(If this should be posted elsewhere- feel free to move it, or tell me where to repost it.)
I have a fairly typical Chicago-style, narrow (like 22'), 2-story, balloon-framed house that was built in the 1880s or 1890s, and converted to a 2-flat later.
At some point (maybe in the 2-flat conversion?), the 2-story back porch was enclosed, and the new siding was continued down to grade level- by adding some framing between the wood columns (on piers) that support the porch.

Asked By Ben Rush | Aug 30 14
34 Answers

My house has high levels of CO2 / carbon dioxide, every room is between 1100 ppm to 1200 ppm according to an air quality test I had. There are only 2 grown occupants and it's a 1000 sq. ft. brick house. No pets or plants, gas stove / furnace / water heater.

The basement was the only area that had between 900-1,000 ppm of CO2. I've read ASHRAE likes to see under 1000 ppm of CO2. We do have headaches & drowsiness but aren't sure if it's strictly from CO2. For reference, our CO (carbon monoxide) numbers were all under 2 ppm.

Asked By Jeff Watson | Mar 9 14
2 Answers

Hello,
I have a 1 1/2 story cabin that I am insulating. The second story was constructed using engineered attic trusses. The top chords are 2 x 6 and the knee walls are 2 x 4. Metal roof with soffit vents and ridge vents. My plan is to fur the sloped top chord with a 2 x 4 on edge. This would provide me with 9" of space. I will put allow 2" of ventilation space and install 1.5 " XPS rigid foam board as my baffles, followed by 5.5" of roxul comfort batts, 6 mil poly vapour barrier and drywall. The 2 x 4 kneewall I will build out also with 2 x 4, giving me 7 inches of space to fill.

Asked By Dawn Roberts | Aug 30 14
1 Answer

I live in the San Francisco bay area and am going to use 1-1/2" rigid foam board and a rain screen on the exterior of my house. I have read numerous articles in regards to using insect screen at the tops and bottoms of the rainscreen wall, however no specific details about the type of insect screen is ever mentioned.

There are numerous types of insect screens (Aluminum, Fiberglass Bronze, galvanized, etc.) available.

Asked By Randy Mason | Aug 30 14
6 Answers

My 1927 house has balloon framing, real plaster walls on rock lath, and no vapor barrier. It has cedar shingles over tar paper.

If I blow insulation into the walls, will I create a problem with vapor from the house condensing inside the walls? Even without insulation (current condition), can I close the top of the walls in the attic or will that also allow water vapor to condense in the walls?

Asked By RUTH HENDRICKSON | Aug 29 14
Register for a free account and join the conversation


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