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!

1 Answer

I considering adding a radiant foil barrier on top of the the blown insulation.
What are potential problems could I have, as a result of this installation? Moisture problems? Our home is in Northfield, MN 55057

Asked By gary schutte | Aug 27 14
1 Answer

I have a question about cladding. I’ve always liked brick, but it’s easy to screw up and moisture management and insulation questions abound. So, I’ve been thinking about fiber cement siding with a rain screen. However, it appears that it’s difficult to put rain screen strapping on over exterior insulation without having bowing, and this tends to telegraph through to the cladding. This leads me to ask about mortarless bricks like Novabrik. If you don’t have mortar and do have a rain screen gap, don’t most of the moisture and insulation issues with brick veneers go away?

Asked By andrew c | Aug 27 14
10 Answers

I would like to ask the math pros here on how to calculate heat loss from infiltration rates.

I have seen so many different formulas in the last weeks that my head is hurting.

So would like to have a "reliable" formula that could be used in my never-ending expanding excel spreadsheets !

Something with at least a little bit of proven precision, that could be used to effectively get additional heat loss using door blower results or planned target value.

Links or straight formula please :)

Asked By Jin Kazama | Aug 25 14
2 Answers

I am in the process of trying to determine how much strapping spacing is needed on a ceiling to support 22" of blown-in cellulose above it. The strapping is 1x4 pine and I plan on spacing 16" OC whixh makes the space between supports of 12". The strapping is holding 6 mil poly up against the bottom chord of the truss. There will be some ballooning of poly downward in those squares between truss and strapping. 5/8" Sheetrock will be used up against strapping to finish. Thanks in advance.

Asked By Matthew Michaud | Aug 26 14
13 Answers

I was speaking with my passive house consultant the other week, and she expressed concerns about boring critters and subsurface rigid insulation. She had such an experience with some insulation in her garden (It was put in one season and removed at a later time as she got back to completing the project.)
Now, I know all about the ate/termite protection used in these insulation products, but what about larger critters that would love to have a warm dry home?

Asked By Steve Young | Aug 16 14
7 Answers

I would like to decide on putting in solar panels to reduce energy costs.

I have read about the next generation solar panels not being to far off.

Question: Would it be better to install current solar panels or wait for the new type that will be coming shortly?

Asked By John Alberti | Aug 26 14
8 Answers

I got a quote for windows from Intus and thought it the quote was high. But I do like the windows themselves.

A 24 x 48 fixed window was $385 with a simple grid pattern white - thats 48.13 sft
A 36 x 48 operable window was $745 white - thats $62.60 sqft faces west
and a 42 x 72 operable window white $1000.00 thats $47.62 faces west

I read somewhere on GBA blog that a typical Intus window was $30-35 sft fixed and $40-$45 operable, I have 34 windows and only 7 are operable and totals $28,000, is this reasonable or not???

Asked By Sam smith | Aug 26 14
1 Answer

I recently installed this model Zehnder HRV, and now need to learn how to balance it. The manufacturer's installer manual is too brief on this procedure to be helpful. Is there anyone out there who can anyone give me the detailed procedure on how to balance this HRV?

My main concern is to ensure the intake/exhaust is balanced and that I am not pushing too many CFM's into/out of the house. I don't care too much about getting each room's cfm perfect at this point - since I'm going to be continuing to renovate the house. I just don't want to be pushing moisture into the walls right now.

Asked By Matthew Robinson | Aug 27 14
4 Answers

We are retrofitting a slab on grade portion of our home that has an existing 4" thick concrete slab with a thinnish layer of insulation underneath. We are going to install radiant heating over top of this existing slab. There's an existing fireplace in the room and the hearth is 3 inches above the existing slab.

So to keep the new radiant overall thickness to roughly 2 1/2 inches to allow for 1/2 inch for wood flooring I was going to install 1/4 inch thick extruded poly (Owens Corning fanfold) then Hilti wire mesh, then 5/8 tubing, then gypcrete.

Asked By chris hoy | Aug 26 14
33 Answers

Does anyone know if there are any companies that offer residential fuel cells on a lease program?

I met someone at RESNET this year who worked for a company that was offering such a program, but I have not been able to reach him since mid-March.

I'd like to utilize one to carry the electrical load on my future home.

Thanks for any help you can offer.

Asked By Mike Collignon | Jul 24 12
Register for a free account and join the conversation


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