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!

3 Answers

Best wall system for my area and budget?

I will be building a 2,300 sf house in Nebraska, Zone 5A. It will be a two-story, 38' x 31' with four walls, an attached garage, and a 4:12 hip roof. Due to a small lot and houses next door, most windows face either the Northwest or Southeast.

I am on a pretty tight budget here, and was quoted the price for 2x4 walls. I can squeeze another $5-8k or so out of the budget to improve the wall system. What should I do? I was thinking 2x6 with foam board. Thoughts? Thanks!

(The floorplan is at the drafters right now, but I will post it later if anyone has any thoughts on it.)

In Energy efficiency and durability | Asked By Cameron Guenzel | Aug 29 12
2 Answers

Cost of air sealing and insulation

I just read the results of this research project by the EPA. In it they air seal a home built in the late 1970's and bring it from~ 0.93 ACHnat to 0.50 ACHnat. And they also add insulation to the attic (from R15 to R38), rim joists (from R0 to R11), and floors over the crawl space (from R0 to R11).

I'm wondering:

1) Is that type of air sealing accomplishment realistic in the real world without a deep energy retrofit?

In Energy efficiency and durability | Asked By Stephen Horvath | Aug 29 12
3 Answers

I want to place insulated glass units in a frame wall.

I want to place insulated glass units in a frame wall. At this point, the wall is studs with plywood sheathing. What is the best way to frame, secure and trim these IG units?

The middle window is 6' by 6'. Flanking units are smaller. Windows face south. The windows are fixed, glass only, no nailing fins. Exterior trim will likely be rough sawn walnut because it holds up to moisture. Located in SE Iowa

In GBA Pro help | Asked By Redstone Group LLC | Aug 28 12
3 Answers

How do we calculate skylight placement?

We are building a new house in DeRidder,Louisiana. Our walls are 8 inch cement block(featherlite rock face), 8 ft, 9 inch to top of block. Roof is 8 in 12. Kitchen faces directly south. Kitchen island runs from 6 feet inside block wall to 13 ft and is 4 ft wide. We want to install a velux skylight( GGL P10 3073 ) in the roof running long way with the kitchen island. We want the sun angles average north peremeter(probably noon, September 21) to stop at the north end of the 3 foot tall counter with perhaps soapstone on top of it.

In General questions | Asked By Catherine Tilton | Aug 29 12
2 Answers

Upgrading garage insulation

My bedroom is over an unheated 2 car garage. The ceiling has 2 heating vents running 20' which are not well sealed and show signs of moisture condensing. The 9.5" joist spaces have wedged in 6" fiberglass kraft faced insulation. The joist cavities are open to a ventilated soffit at the door end. I'm going to remove the insulation, seal the 2 heating/cooling ducts and use duct wrap their entire length. I'm going to spray 1" of isocyene foam on ceiling to seal the entire bedroom floor from the garage and then reinstall the fiberglass before reinstalling drywall. The house was built in 1992.

In Energy efficiency and durability | Asked By james savage | Aug 29 12
1 Answer

How do you detail a plenum space with ducts that is below an unvented/insulated flat roof ?

This is a multi-family project in zone 4b which will have a drywall ceiling. Above the ceiling is a 2' space where ducts will run. CCF will insulate the underside of the roof deck and the walls of this plenum space. So, ducts will be in conditioned space.

In Energy efficiency and durability | Asked By sue bryant | Aug 29 12
8 Answers

Attic insulation retrofit

We live in a 30 year old split level house in North-central Alberta. The house faces south and gets a lot of sun in the front (1 story), but a lot of shade in the back (2 story) It has brick, aluminum siding and stucco for exterior surfaces and an asphalt shingle and tar paper roof. There is a full basement that is partially finished/insulated.

Attic #1 has fiberglass batts, with a south facing gable vent and we added a rolled ridge vent when re-shingling (asphalt and tar paper). It also meets with the south wall of the 2nd story.

In General questions | Asked By Kim North-Central Alberta | Aug 26 12
2 Answers

Does Loosefill Attic Insulation Require an Air Gap Between Insulation and Roof Decking?

Does loosefill attic insulation (specifically fiberglass or cellulose) require an air gap between the insulation and roof decking to be effective? Once I've installed baffles to protect the soffit vents I would like to blow insulation all the way to the roof decking at the eaves on houses with shallow pitch roofs. My goal being of course to maximize R-value. Any reason not to do this? Thank You for sharing your knowledge.

In Energy efficiency and durability | Asked By Randy Ransom | Aug 29 12
9 Answers

Drafty Gas Fireplace Insert

In the winter (Alberta) we get huge drafts coming in the grills of our gas fireplace insert. I've noticed it when it's not in use, especially at night but it seems inconsistent and not necessarily predictable by the temperature or audible wind. From the outside there is a fresh air intake on the chimney and there is a metal chimney exiting the top of the old stucco chimney.

What can I do here? Who would I even call to look at it? My husband likes the fireplace but I am really concerned about the draft coming in when it can be -30 C here and our winter is long.

In General questions | Asked By New to North-Central Alberta | Aug 26 12
5 Answers

Broan automatic make-up air damper with a dedicated HRV?

Cold climate zone 5 - central OH. Mechanical ventilation strategy being considered for the new build is as follows:
- Balanced system featuring an HRV with "dedicated" ventilation ductwork. HRV being considered is the RecoupAerator 200DX equipped with an ECM motor from UltimateAir. Pulls stale air from bathrooms and laundry rooms and provides fresh air to the great room and bedrooms.

In Mechanicals | Asked By Milan Jurich | Aug 26 12
Register for a free account and join the conversation

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