Community: General questions

Q & A Instructions

[Click map to enlarge]

The 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!

2 Answers

Weight bearing capacity of electrical box for a chandelier

Hi everyone,
In looking for finishings for our house (new build) we found a crystal chandelier we liked but it's a bit on the heavier side (approx 40lb). in the foyer our electrician currently has an octogon box wired and attached to a 2x4 brace (see picture attached)..
My concern now is going with a heavier chandelier with this type of box and/or how it is supported in terms of its capacity to bear the weight of the chandelier we are looking at?

Many thanks in advance


Asked By Rick Manitou | Apr 29 17
4 Answers

Advice to GBA readers with goofy screen names

Because of a web site glitch, the GBA site hasn't been displaying the names of recently registered readers properly. Lately, we've been getting screen names like "N/A N/A" and "User-85612."

Some new readers have chosen aliases like YellowFrog or RedSoxFan.

GBA encourages the use of real names. If you have been assigned a goofy screen name like N/A N/A, or if you are willing to change your screen name from YellowFrog to your real first and last names, there's a way you can fix the problem.

Asked By Martin Holladay | Apr 30 17
6 Answers

Venting a roof framed over a roof

I have a ventilation question I have just thought of while designing a home. The house is a 1.5 story home (framed as a cape style but turned 90 degrees so the front entrance is the gable wall).

Asked By User-6801629 | Apr 27 17
3 Answers

Exterior wall installed on perimeter of OSB floor, yet rest of room is a cement slab?

Hi all.
We recently purchased a house and upon ripping the carpet out in one of the bedrooms noticed that the exterior wall has been built on top of an osb type floor, however directly adjacent is the cement slab. I've attached a picture.

I'm hoping that someone here may provide some insight into why the slab/osb combo has been used. The cement slab has heating put in the cement.

The house was built in 1998. It's considered a 'walkout'.
We are Alberta Canada. Thanks.

Asked By Frugalmumma | Apr 26 17
3 Answers

Am I OK to lay down my plywood subfloor at 19% moisture content?


I tested all of my 4x8 cdx plywood in the middle of the 5 sheets, and 2 pieces are at 19% moisture content (the rest are between 10-17%).

Should I go buy 2 new pieces or am I too concerned over the moisture content? I was reading that anything near the 20% range is way too high for plywood.

I purchased these 3 weeks ago and have been stacked in my shed. I did not test when I first purchased but I certainly would assume that they would be dryer.

Also, please see the pictures below. Does this look like water damage or mold? These are the two pieces that measured higher.

Asked By Grey Wolf | Apr 27 17
7 Answers

Stone veneer over Zip sheathing

I've read a few articles on stone veneer, and see the statement that stone veneer on OSB is one of the riskiest wall assemblies. Is this referring to having no WRB and rainscreen?

We are in Climate Zone 5, have ZIP, but will also use Asphalt Felt and Rainscreen.

Asked By Bridget Lamberson | Apr 28 17
4 Answers

Airtight electrical boxes in masonry house?

Do I need to use airtight electrical boxes on a masonry/concrete house?

Cement plaster will be my interior airtight layer, but people are telling me that wall itself is airtight enough not to warrant the search for airtight electrical boxes.

Asked By davor radman | Apr 27 17
2 Answers

Moisture control / insulation for new cinder block shop with loft / den.

Hello Folks

I've been reading through the forums for an answer to this question, but haven't been successful in finding one. I'm building for the first time, so this is a learning curve for me.

I live in west Florida, and have a project in the works. I'm going to be building a 55ft x 38ft workshop, that will be 2/3 work space, and the remaining 1/3 will be a loft / den living space with a small kitchen, laundry area, and bathroom. So around 1400sq ft. I am planning on controlling climate with a 3 air handler mini split system.

Asked By brew0688 | Apr 24 17
1 Answer

Should I place a vapor barrier on an inside wall?

I have built a wine room and have been advised that I should create a vapor barrier on the walls outside the wine room since I do not want water vapor to seep through the walls when the cooling is running. Is that correct.advisable? I live in New Mexico and have had a smaller wine room for eight years with no discernible problems and am wondering if I should do that. Also, I have been advised to place a vapor barrier on the outside stucco walls as well. Any comments and advice would be welcomed

Asked By Sabawa | Apr 26 17
22 Answers

Need sizing advice on a minisplit unit

I installed a Mitsubishi FH12NA in summer of 2014 when they first came out. I live in inland San Diego, and it can get hot, like 10-15 degrees hotter than the coast.

My condo is a studio and is only 420 sq ft. I'm on the upper unit of 2 stories. I face East and South. I have a skylight and dual-pane windows. Building is 1978 construction.

My Mitsubishi is weak. I set the temp and it will barely do anything. I have to set the temp to 61 and manually put the fan on high for it to do anything. Even "powerful" mode is weak.

Asked By aypues | Mar 16 17
Register for a free account and join the conversation

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