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!

8 Answers

Feedback on house layout/orientation

I posted a question several months ago looking for feedback/constructive criticism on a new home layout I was working on. I've tried to incorporate a lot of the advice given into my revised layout. Was curious to see if any of you experts had any further thoughts.

In General questions | Asked By GREG GRIGUTIS | May 14 18
4 Answers

Insulation for a stick-frame roof — but we want the exposed beam look

so we bought a house that was built in the 50s and we had take out the drop ceiling and old drywall ceiling above that to run new wiring.

Bottom line - wife saw the open ceiling and asked if we could keep it that way and ya'll know that saying. Anyways - I look at the roof and it is just 1x6 boards laid across the rafters with a shingle roof on top. Roof nails piercing the wood all over.

So I would like to give my wife the look of exposed beams but I am thinking how do I insulate it. The roof is brand new on the outside, so I don't want to disturb that.

In General questions | Asked By A.J.W. | May 16 18
6 Answers

Multi/mini-split cassette buried under blown in insulation?

I am in the planning phase of a house renovation (San Francisco Bay Area, zone 3C) which includes a new HVAC system and am considering a multi-split system with ceiling cassettes and ducted units. The unconditioned attic insulation is blown in fiberglass on the attic floor. Although not as efficient, the ducted units may have to go into the attic due to space constraints. The ducting would also be buried under insulation. None of the manuals and online references I have found seem to specify whether ceiling cassettes or ducted units can be buried under blown in insulation.

In Mechanicals | Asked By Wilson C | May 15 18
4 Answers


Yesterday I came across this blog: https://junkit.ca/5-things-you-thought-you-could-put-in-the-recycling-bin-but-cant/ which left me in surprise. It says pizza box, water bottle cap, wet paper, aerosol can and so are not recyclable. This is a new knowledge for me. But is it true? I know recycling is important for the earth as well for the future generations to come. So I'd like to start a discussion based on recycling here.

In General questions | Asked By emma3434 | May 16 18
10 Answers

Mitsubishi PVA/PUZ a "Central heat pump" or "mini split"?

Looking to replace my oil fired forced air furnace with an air source heat pump. Cold winters here in MA so I like the Mitsubishi hyper heat units. MA has a heat loan program for 0% financing for 7 yrs with qualifying units (>=16 SEER, >=8.5 HSPF for "Central heat pumps"; >=18 SEER, >= 10 HSPF for "Mini-split heat pumps"). The MXZ-4C36NAHZ is rated at 15.8 SEER and 10.1 HSPF pairing with a MVZ-A36AA7. However, the PUZ-HA36NHA5 is rated at 17.8 SEER and 11.0 HSPF, paired with the PVA-A36AA7.

In General questions | Asked By Scogan | May 12 18
10 Answers

Attic insulation - R-21 and radiant barrier

Hi I know this topic has been asked a lot but I was hoping to get some info I could not really find in other posts.

In Energy efficiency and durability | Asked By msimm15 | May 15 18
9 Answers

When is it necessary to use foil-faced insulation?

I am insulating an exterior wall (8" CMU with direct applied 1/2" stucco) with 1 1/2" rigid closed cell insulation which is placed on the inside face of the CMU in a furred out (1 5/8" metal framing) interior wall. can I use regular closed cell insulation or is this an application which is better suited for a foil face closed cell rigid insulation.

In General questions | Asked By Ebt111 | May 15 18
3 Answers

Low-maintenance siding for Vermont

I am considering changing the majority of the siding (3000-4000 of 5000 sq ft) from weather atlantic cedar rainscreen design to a low maintenance pre-finished siding to save money on a project. Anyone have experience with these and/or recommend other options?

Certainteed Icon prefinished 30 year 16' - https://www.amerhart.com/certainteed-icon-composite-siding/
Boral Truexterior prefinished 15 year 16' - http://www.bostoncedar.com/boral-truexterior-pre-painted-siding/
Everlast 12' - prefinished lifetime - https://www.everlastsiding.com

In Green products and materials | Asked By J M | May 15 18
9 Answers

Exterior spray foam insulation over OSB?

Getting ready to building a home and couldn't find much info on this except in commercial applications. Had a meeting with the insulation contractor (in business since 1976) and explained to him that I wanted an airtight home with good insulation, I mentioned ZIP-R with blown in cellulose or loose fill fiberglass.

In Energy efficiency and durability | Asked By Roger V. | May 13 18
2 Answers

Alternative ventilation for small homes in cold climates

The Cold Climate Housing Research Center (CCHRC, www.cchrc.org) is researching alternative ventilation options that could be better suited for small homes (under 1500 sq ft. typically with less than 50 CFM required ventilation) in Alaska.

In Mechanicals | Asked By CCHRC | May 14 18
Register for a free account and join the conversation

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