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!

6 Answers

Neoprene vs. EPDM sill sealer?

I've been looking comparing the two types of rubber to use for sill sealer. Everyone seems to recommend EPDM gaskets from Conservation Technology. All I need is a flat tool (without the raised edges that Conservation Technology offers).

Are there any drawbacks to neoprene?

Where are some other places to buy?

In Green products and materials | Asked By Grey Wolf | Apr 17 17
23 Answers

"Utility Score" is now showing up in Colorado MLS searches

Finally there is a pretty good way for house hunters to evaluate the energy efficiency of homes that are on the market.

I love the fact that the rating is in dollars per month, the only metric that is meaningful to the average homebuyer. Smaller homes have a lower bill, as expected.

Do any other states have this yet?


In Energy efficiency and durability | Asked By Kevin Dickson, MSME | Apr 8 17
3 Answers

Moisture barrier between crawl space and seasonal living space

Our 50 year old 3 season cottage (Kincardine Ontario) on the shore of Lake Huron is uninsulated and closed from mid October to mid April. In the summer time it is pretty much wide open except when the rain and wind are blowing sideways.

In Energy efficiency and durability | Asked By Grant Robinson | Apr 13 17
22 Answers

Remodel in southern NH

Having started down this path in RI a couple of years ago and pulled the plug we're now about to purchase a 1600 sq/ft gambrel style home in southern NH and do some remodelling.

It's a 1986 construction, 2x6 exterior walls (presumably with batt insulation), original wood framed double pane windows, vinyl siding, oil fired baseboard heat, no A/C, electric hot water. I'm planning a phased remodel, starting with re-doing the kitchen and half bath on the 1st floor as soon as we get the keys.

In Energy efficiency and durability | Asked By Ben Balcombe | Mar 6 17
3 Answers

Permanent wood foundation (PWF) backfill height?

All the documentation I've found on PWF basements never shows insulation under the slab floor. The allowed back fill heights are always referenced to the bottom of the bottom plate of the wall which coincidentally is the bottom of the slab.

If under slab insulation is installed after the perimeter PWF walls are in place, the slab will be raised by the thickness of the insulation. With under-slab insulation is the backfill height the height above the slab bottom? or the bottom of the bottom plate?

In Building Code Questions | Asked By Jerry Liebler | Apr 17 17
3 Answers

Deck footers

Good evening Everyone,

I'm attempting to build my first deck this spring. I've dug holes for footings and just passed my footing inspection.

The Deck code here in maryland dictates that holes are to be a minimum of 30" deep with an 18" wide by 10" deep concrete footing. Once you have that you can either use concrete piers to get your posts out of the ground or you can place the post right on the original footing.

In Building Code Questions | Asked By Andy Pappas | Apr 17 17
4 Answers

DensArmor in bathroom

We installed Dens Armor in all the bathroom, walls and ceilings.

We are putting in full showers, already manufactured, no tile work on the walls. The master bath is an Onyx Shower. Cement board is going on the floors for the floor tile work.

Is the Dens Armor suitable for the walls surrounding the shower?

Dens Armor in the kitchen for the backsplash by the sink, looking for recommendations if for a wall underlayment.

In General questions | Asked By Bridget Lamberson | Apr 17 17
1 Answer

Bathroom exhaust vent sizing in 2x4 walls

We recently bought a front to back split so there are essentially three levels with our master bedroom and bathroom at top. It turns out the bathroom exhausts for all three bathrooms run into the attic but luckily there doesn't appear to be much mold. They used flexible duct.

We are replacing all of the old, rattling fans ducts, but we have 2x4 interior walls and a long run for the basement bathroom.

Can we use rectangular metal duct for the vents or do we need to stick to round?

In Mechanicals | Asked By Allysn Moore | Apr 18 17
1 Answer

Housewrap under rigid foam AND taped rigid foam at windows

the set up: Climate Zone 3. I'm using a standard house wrap between the OSB sheathing and the 1" rigid foam. The rigid foam will have all seams taped and will act as the primary WRB behind 3/4" vertical furring and lap siding. The Question : How do I terminate the house wrap at windows? just bring all the way into the "outtie" window bucks (caulk to buck), install rigid foam, then install window peel and stick flashing on bottom/part way up the sides. Install window. Would you recommend a 2nd layer of house wrap around the windows? Attached to the rigid foam?

In Green building techniques | Asked By Inger Peters | Apr 17 17
12 Answers

Are minisplits not allowed as the only heat source?

We are in Minnesota (Zone 6a). Building this summer on 12 acres. 2200 sq/ft single level (maybe a bonus above garage), slab on grade.

After speaking with the first HVAC company, they claimed that the LJ's would not allow mini splits as the primary heat source in a home. I would have to install baseboards, in floor heat, etc. They said I would be required to have a heat source in every room. I got the sense they were trying to sell me on radiant, which I have learned, I can comfortably avoid if I insulate the slab well (they also disagreed with that).

In Mechanicals | Asked By Scott K | Apr 15 17
Register for a free account and join the conversation

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