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!


10 Answers

double ceiling (similar idea to double wall)

can't find any info on this idea.
i'd like to insulate an awkward existing post and beam structure. it has a low-angle metal roof built over the original flat roof with its torch-on membrane still intact. the attic space tapers to nothing at one end, so not enough attic space for insulation above the torch-on layer. inside flat ceiling height is much taller than i need.

wondering if i could build a "double ceiling", similar to a double stud wall, but oriented horizontal instead of vertical?

In Green building techniques | Asked By Clark Lewis | Nov 9 17
1 Answer

What are the general ingredients of spray-in insulation?

Hi,
I'm looking for the ingredients for a general spray-in insulation. I wondered if you could help me with that. I'm doing an insulation project for an extracurricular activity, and I want to use this product, but I'm not sure I'm allowed to, and my teacher doesn't know either. It all depends on the ingredients, or the components. If you will please get back to me soon, I would greatly appreciate it. Thank you.

In General questions | Asked By alli_1205 | Nov 9 17
1 Answer

What are the general ingredients of spray-in insulation?

Hi,
I'm looking for the ingredients for a general spray-in insulation. I wondered if you could help me with that. I'm doing an insulation project for an extracurricular activity, and I want to use this product, but I'm not sure I'm allowed to, and my teacher doesn't know either. It all depends on the ingredients, or the components. If you will please get back to me soon, I would greatly appreciate it. Thank you.

In General questions | Asked By alli_1205 | Nov 9 17
8 Answers

Heat pump dryer for $598 (if you're in southern Ontario, Canada)

This dryer has been discussed several times on GBA and i bought one (for delivery soon) being ventless and quite energy efficient.

Since its discontinued and this is an amazing price i thought i'd post it here for anyone who may live where they can get it

https://www.badboy.ca/whirlpool-7-4-cu-ft-ventless-electric-dryer-ywed99...
https://www.badboy.ca/whirlpool-7-3-cu-ft-ventless-electric-dryer-ywed99...

Discussed on GBA
http://www.greenbuildingadvisor.com/community/forum/green-products-and-m...

In Energy efficiency and durability | Asked By Alan B | Jul 7 17
2 Answers

Can you connect a bubble up raydon system to the air system?

An air system was already installed for radon when we purchased our house. We had a water system installed after (bubble up) and the installer said he could run the water system vent into the air vent. We just had the bubble up serviced by another company and was told what the first guy did was illegal and it will cost $4 to $500 to fix it. Just trying to find out if it is legal to do it.

In Building Code Questions | Asked By maglady | Nov 9 17
33 Answers

Another garage heating question

HI

So I'm building my dream shop/garage, then I going to build my house.. So my wife is making sure I stay on budget.

Building is 64'x 40' x 14'

ICF frost walls that will be 4' below grade and 2' above grade then 12' of 2x6 walls on top for 14' ceiling.
Walls will be taped and sealed OSB best I can and have 3" (reused) Polyiso on exterior and filled with Roxul.
Attic spaced will have blown in cellulose, R???
Floor will have 4" foam under slab. If needed??

South facing side (64') will have 4 large 5' x 5' windows, casement style on half of 2 windows.

In Mechanicals | Asked By Dave B | Oct 4 17
8 Answers

Seattle Insulation Retrofit

Location: Seattle, WA, Marine Zone 4C
Type of Construction: Wood frame single family residence
Year Built: 1947
Size: 690 sq ft main floor, 380 sq ft basement

I purchased a home several years ago that had previously been a rental house for 30+ years and owned by the same family since it was built. It has seen very little in the way of alterations and updates. Which is good and bad. No need to undo poor workmanship but just about everything needs upgrading. Perhaps a blank slate?!

In General questions | Asked By Jeremy Sharp | Nov 7 17
4 Answers

I have a question about Heat recovery ventilators.

Hello,
I have a home with with 10" of dense pack cellulose in the walls and 14" in the celling.
I am looking to install a h.r.v. I have a very open floor plan and would like to use only one vent in and one vent out. Drawing air from the upstairs bedroom and putting new air into the living room downstairs. Air would travel through the stair well at the other end of the house . Calculations say I need about 100 cfm. Is there any problem moving this amount of air through only one duct?

George

In Mechanicals | Asked By george finlay | Nov 8 17
6 Answers

Casting concrete to repair rubble foundation?

I have a crawlspace that leaks air badly in the winter and I would like to insulate (I live in Minneapolis, MN for reference). Upon embarking on the job, I uncovered a rubble foundation that is in need of repair. This foundation is part an old extension to the house and is of much lower quality than the original limestone brick foundation. It also looks as if it has been repaired at least once in its life as there are some random chunks of red brick and glass embedded in the wall which I doubt were original.

In Energy efficiency and durability | Asked By Frank Thorton | Oct 16 16
2 Answers

Closed cell foam in in vented roof

I have been able to avoid using spray foam up until now but with recent code changes in our area we are now forced to use it.

On a current job we are framing a new roof directly on top of the existing old roof sheathing because the owner wants to expose the hand hew beams of the original frame below. The new rafters are 2x8 and the plan is to spray the bays with closed cell foam on a warm day and then immediately sheath and roof.

I’m a concerned because the rafters will have no time to dry out before being foamed and I'm concerned about lumber shrinkage

In Energy efficiency and durability | Asked By Judson Aley | Nov 8 17
Register for a free account and join the conversation


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