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

Home Air quality test kits... any good?

I am looking to get some insight to what is floating around in our home. We are planning on having a baby soon and after some remodeling and asbestos removal, I want to make sure everything is ok.
To have a pro come out and test, can get very costly and so I have found a few companies that offer home test kits. These 2 companies that provide testing kits had the most information available.




Asked By J Loc | Feb 15 12
9 Answers

Renovation, exterior Rigid while dealing with setback codes

Hello all,

I'm still working on my garage plan. We now plan to add a room above our garage.

I was looking at wall builds and like the exterior rigid build the best for durability and thermal bridge advantages. However, this is going to be a room over a garage "renovation", and under building codes, my renovation/addition cannot be any further into my sideyard setback (it already is grandfathered in).

However, I suspect that they would not tag a couple trim "details" encroaching.

Asked By Garret Olson | Feb 14 12
3 Answers

Bonded Logic insulation products

Is anyone aware of any health issues that have been reported with the use of the Bonded Logic cotton insulation products? This is the insulation made from blue jeans (and thus, is blue in color). I had read something a long time ago and can't seem to reference it. We are looking for a formaldehyde free, low, or no, VOC exterior duct wrap for the attic HVAC systems. I am guessing that Johns Manville Formaldehyde-free duct wrap would be a good choice but wanted to look at non-fiberglass as well. Thanks.

Asked By Jas Thurber | Feb 15 12
8 Answers

Ideal wall for 3C climate zone and in seismic zone

I am a homeowner interested in your opinions on ideal wall insulation for San Francisco in the 3C climate zone.

We are planning a new addition with 2 x 6 walls which I would like to fill with dense, wet spray cellulose insulation.

I have asked everyone I can locally about using one 1 inch polysio on the exterior and I always get - "not done in this climate", "not seismic-safe" "will not pass inspections due to shear strength requirements".

Can 1 inch polysio be put over the top of plywood and the waterproofing?

Asked By Donovan Corliss | Jan 19 12
11 Answers

Wall construction alternatives

House to be built is located in central OH ... zone 5 cold climate ... HDD of 5708 and CDD of 797. Aiming for the following R-values: basement sub-slab (R-10), basement walls (R-16), above grade walls (R-32) and attic (R-49). Planning 2" of XPS rigid foam under the basement slab, 2" of DOW Perimate XPS rigid foam outside the poured concrete foundation walls with a rigid foam lining the interior basement wall. Is EPS recommended over XPS or Poly-iso for the interior basement walls to aid in drying towards the interior?

Asked By Milan Jurich | Feb 10 12
9 Answers

Comparing Window performance

I am trying to compare apples to apples on various triple window brands. When folks here quote the U value of a window I assume they are talking about Uw (whole window). I was told by a vendor that that value varies with the size of the window. What window size are people assuming when they say the U is a certain value?

Asked By Elizabeth Kormos | Feb 14 12
3 Answers

Drylock and basement insulation retro-fit

A follow up question after reading "RR-1108: Hybrid Foundation Insulation Retrofits: Measure Guidelines." As detailed in one of the alternatives in that article, for my basement retro-fit I am planning on using foam panels installed directly to the foudation walls, as the first step towards coverting the basement to conditioned space (playroom). I will likely use foam panels or plywood with a bubble mat (like dry-core) for the floors.

Asked By Rick D | Feb 14 12
6 Answers

Efficient HVAC for small apartment

I have a 500 sq ft garage apt with 20+ year old central electric heat and AC that I want to upgrade to a more efficient system. Since it has two rooms and ductwork, I'm thinking a mini-split is not the best option. I now have natural gas and could put in a 95% efficient gas heater (more efficient than electric heat of any kind I think). A 1 ton AC unit seems like a good option for cooling but I can't find one, only a single stage 1.5 ton unit which is overkill. My nephew is an HVAC installer in Texas and he has recommended a 2 stage 2 ton unit that will act as 1.25 ton in lower stage.

Asked By Dorothy Prowell | Feb 14 12
2 Answers

Is there a problem with too much attic ventilation?

As I finalize the soffit & vent design for my new home, I'm coming up with some out of balance numbers.

The attic area is ~4200 sq ft (this include space over garage). Garage will be insulated and drywalled, preped for heat but not heated at first. Using 150:1 I come up with an NFA req of 28 sq ft or 4032 sq in.

Half of the roof has a 8:12 pitch, the other half 6.5:12

Due to the roof configuration, I'm planning on using ventilated ceiling treatment, such as invisivent) on the porch ceilings to add to the middle roof intake ("true soffits are minimal here).

Asked By Jim Orasky | Feb 14 12
11 Answers

Fighting the inspector- double stud wall NOT "ci"!

This is how great building officials can be. I am working on getting my project qualified with the HERs raters and Energy Star programs to qualify for new construction rebates from local utility companies. However the inspector is claiming a double stud wall does not comply with IECC 2009 since it does not have r5 ci / 13 cavity as well as r5 ci at the box sills. I am trying to explain to him the double stud wall achieves the same thing ci does, not to mention my walls are roughly r40 overall.

Asked By Jesse Lizer | Feb 13 12
Register for a free account and join the conversation

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