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!


13 Answers

USA New Wall & Swedish platform framing

Hello,

I recently came across Greg La Vardera’s website http://blog.lamidesign.com

Although I have read much on energy efficient wall types here, I haven’t noticed any comments on the USA New Wall. I am interested in other peoples opinion on this construction and how it compares to other energy efficient wall types. (I am thinking about the Building Science Corp s list of walls and how they score relative to each other -http://www.buildingscience.com/resources/high-r-value-wall-assemblies )

In General questions | Asked By Mitchell Daniels | Nov 12 13
15 Answers

Run furnace blower or HRV?

We are building a home is southeastern Michigan. It will have 3 110cfm bath fans (one in basement bathroom) and one 80 cfm bath fan (toilet room) and a 400 cfm hood range. I am concerned about air quality, as we a building a very tight house. Our HVAC contractor has said that he can simply program the furnace to run the blower every 1/2 hour to bring in more air which would be filtered. I believe he will also have a scuttle installed on the furnace. What are your thoughts? Most of the HVAC professionals I have talked to say that HRV systems don't work that well anyways. Thank you!

In Green building techniques | Asked By Carolyn Farrow | Apr 20 16
36 Answers

Where is the excess humidity coming from? No obvious sources

I always read about optimal (relative) humidity being somewhere within the 30%-50% range.

I started monitoring the humidity in my single story brick house over winter it appears it's always in the upper 40% range. I am curious why it is so high. This is an old 2-wydthe brick house in Zone 5.

Sample readings:
- Basement: 52% @ 59deg, DP: 41deg
- Main floor: 47% @ 68deg, DP: 47deg
- Outside: 60% @ 33deg, DP: 22deg

Usual suspects:
- 2 people, gone during business hours
- bathroom fan vented outside through the roof, always in use during showers

In General questions | Asked By Jeff Watson | Apr 4 16
5 Answers

Brick steel lintel size

Does anyone has a reliable chart or table for brick lintel length on each side of a brick wall opening? I've contacted brick suppliers and contractors, and apparently is all done by the way is always been done, and I hear 20 different answers.

In General questions | Asked By Armando Cobo | Apr 21 16
1 Answer

Part 2: How best to insulate a 1935 small Cape; is blown in cellulose OK?

Part 2 of my question - Is it ok to blow in dense pack cellulose to the walls of a 1935 small Cape without having a "moisture barrier"? A friend suggested because of the heat/cold differential, there might be condensation, which could moisten the cellulose and eventually damage the frame. The MassSave people say this is unlikely- only in case of ice-dam water damage, for example, would the dense pack cellulose get wet-enough to matter. Thanks very much for your previous comment.
Miriam

In Energy efficiency and durability | Asked By Miriam Chernoff | Apr 21 16
2 Answers

Okay to dry out cellulose wet for 10 days to use in an attic?

My insulation sprayed damp cellulose into the wall cavities, scooped up the waste, and put it in about a dozen plastic trash bags so I could dry it out and use it in my attic. (I know many installers put the waste back in the machine, but he was wary of doing so because of stray nails that could damage his machine, even though I had a clean job site.)

In Green building techniques | Asked By Michael Bluejay | Apr 21 16
2 Answers

Flashing for window installed in double brick wall

I am looking for advice on proper flashing / installation of a replacement window into a rough opening in a double brick wall. I am a complete novice to this, so I appreciate any advice. I do not plan on using a window buck, but install the windows directly into the brick opening, that is to maximize window space in existing opening. It will be an innie window. I have a bit less than an inch gap between wall and window on each side. I plan on using caulk to to seal this, but would not know if there is any way or advantage to use flashing here?

In General questions | Asked By matthias paustian | Apr 20 16
3 Answers

Useful products to reduce summer indoor heat without air conditioning?

I live in northern part of Los Angeles County where summer highs are typically in the 90's and can get over 100 degrees. Our home is a single story home with a north/south facing gables without an air conditioner yet with energy efficient windows & shades plus R-30 attic insulation laying on the attic floor.

During the summer I manually open the windows and shades in the evening and close them in the morning. The roof is supported with 2x4 rafters running in east & west and the attic is 6 feet tall. I wonder if there is more I can to reduce indoor summer temperatures?

In Energy efficiency and durability | Asked By Ken Kolt | Apr 19 16
9 Answers

How do I upgrade a low-slope cathedral roof?

The roof is on a Panabode that I just purchased Zone 4. Haven't taken possession yet so don't have detail pictures. From my investigations the roof is made up of 4X10 longitudinal cedar beams 4 feet apart. The ceiling is 2.5 inch tonque and groove cedar running from ridge to plate. On top of this is 1.5 inches of rigid insulation then half inch plywood sheathing and then torch on roofing. It is about a 1/4 pitch. Can I use the torch on as a vapour barrier and then frame it up with 2X8 and use fibre glass bats, vented?

In Energy efficiency and durability | Asked By Ted Sharples | Apr 18 16
1 Answer

I am working on an indoor pool building

I am working on an indoor pool building. We installed an Armstrong W-H 1100 ceiling system. They did not want us to use the felt lining in this system.

Now the client wants the ceiling panels lined. I need to find a black material to line these panels with that I can use over an indoor pool.

In Green products and materials | Asked By Sue-Ellen Stoddard | Apr 20 16
Register for a free account and join the conversation


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