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

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
15 Answers

This is something that as passed a few times in my background brain processes,

How does SHG on exterior cladding/glass influence heatloss ??

If glazings specs 50%VT , a part of the remaining 50% must be converted to heat?

If exterior cladding on a building is black, and sun is shinning on the south face,
it must affect the heatloss greatly for the shined on walls ??

As an example, let's assume a building up here cold north.
20c inside 0c outside.
Sun shines on a large flat south wall that was cladded with a black painted steel sheets finish.

Asked By Jin Kazama | Aug 28 14
39 Answers

I had R60 blown into my 1000sqft attic where there was previously only about R11. Baffles were installed in almost every roof rafter. Air sealing of attic floor was performed. This is a low pitch asphalt shingled hip roof over the whole house.

Asked By Jeff Watson | Jul 12 14
15 Answers

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.

Asked By Matthew Michaud | May 2 14
3 Answers

4" of 2 lb closed cell spray foam will go on underside of roof sheathing....so roof needs to dry to outside; hence why I am using #30 felt/tar paper instead of a non-permeable ice & water shield.

However, to get my Class A fire rated system, I need to use an ASTM D 3909 cap sheet over the tar paper. How well is this system going to be able to dry to the outside and will there be any issues with this system?

The roofing material is a synthetic shake; Bellaforte by DaVinci.

Thanks-Eric

Asked By eric Mikkelsen | Aug 29 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
Register for a free account and join the conversation


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