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!


0 Answers

Rigid Polyiso in side attics?

As a spray foam alternative, I'm considering using continuous rigid foam along the 32ft long x 7ft slope in my side attic and just spray foaming in the lower joist bays and places where taping is difficult. The attics are about as simple as can be with no dormers or other obstructions. I will need 8" of polyiso to meet my disired R-value (R-48), while keeping the 2x4 rafter bays wide open for ventilation. There are also HVAC ducts and plumbing in the attic, which is why I'd like to convert it conditioned space.

In Green building techniques | Asked By Ryan Griffin | Nov 22 14
0 Answers

ICF & Windows Areas WITHOUT Wood Bucks

I observed an ICF build that did NOT use wood window bucks for the window areas. They used some temporary wood shoring but once the shoring was removed the window area was all raw concrete and ICF/EPS foam. The windows will be installed directly into the concrete using concrete screws and window brackets. The windows will be installed halfway in the window area or otherwise known as an "innie" window.

In Green building techniques | Asked By Peter L | Nov 22 14
4 Answers

Has anyone found a window that meets passive house standards and also carries an ASTM impact rating for the 110 mph zone?

So far the only thing I find that's close is from Dynamic.

In Green products and materials | Asked By Carole Hunter | Nov 20 14
8 Answers

Crawl space encapsulation

Hey Folks - I know the topics has been covered but I am still scratching my head and need some clarification and I will but this project to rest.

Crawlspace Encapsulation

I live north of Seattle, WA. in Bellingham - I believe it to be Zone 4a (Marine Zone)
I have about 1000 sq. ft. of crawlspace I am beginning to encapsulate.
I have no bulk water issues.
I have 12 mil SilverBack liner for the walls and 20mil SilverBack liner for the earth.
I found a great deal on new Polyiso fiberglass faced rigid foam board 2" thick. (Firestone ISO 95)

In GBA Pro help | Asked By William Lucrisia | Nov 17 14
6 Answers

Home energy monitoring programs

I am building a net zero energy home to Passive House standards in the Seattle area. In addition to having it be as efficient as possible, my goals were to use renewable materials (no foam), eliminate thermal bridging. have a protected air-barrier and to keep the OSB warm. I'm using dense packed cellulose in the R-50 walls and R-85 roof (cathedral ceiling with parallel chord trusses). The wall assembly is a double stud system with an inner 2x6 load bearing wall and an outer 2x4 wall.

In General questions | Asked By Gerald Blycker | Nov 21 14
2 Answers

Blower door testing by floor or room?

Hello,

In PassivHaus | Asked By Ryan Griffin | Nov 21 14
2 Answers

Dense packing an eyebrow roof

I have a small eyebrow roof below a shed dormer on the back of my cape style house. The dormer runs for about 25 feet across the back of the house. The roof is attached to the wall studs instead of using the proper construction which calls for the wall to be sheathed first and then the eyebrow rafters attached to a ledger board across the sheathing. I have batt insulation in the wall that is exposed to the roof and to the soffit vents that are cut into the eave below the eyebrow.

In Energy efficiency and durability | Asked By Michael Lee | Nov 21 14
10 Answers

Options for garage heat

I would like opinions regarding options for heating a garage. I know, I know, "Why the H@!! are you heating a garage?" will come to mind for many of you. Others will agree that it saves on car repair costs, improves longevity, and allows for storage of "perishables" such as paint cans, bulk canned garden vegetables, and other things wife understandably does not want in house.

Here are the pertinent factors shaping the decision:
* Super-insulated house, Manual J heat load calc gives 12,400 BTU/h (3.6 kW) peak heating requirement (for garage alone)

In Mechanicals | Asked By Kent Jeffery | Nov 20 14
4 Answers

Is this ridiculous?

We live in a 1600 sqft 2 level end unit rowhouse with structural historic masonry walls from the 1890s.

Housing is really expensive where we live, figure between $400-500 per square foot, so we're trying to balance efficiency & comfort with sacrifices of this valuable square footage. We have a crawl space and attic, and intend to condition both so we can run ductwork without replacing the joists on the second floor.

In Green building techniques | Asked By Mike Madowitz | Nov 21 14
22 Answers

Rheem's condensing water heaters (storage)

Hi,

My 14-year-old electric water heater is starting to look a little long in the tooth. Time to upgrade.

So, I'm looking for intel on Rheem's Professional Prestige Series: High Efficiency Condensing Power Direct Vent (RHE50) or its sister sold by Home Depot - Rheem EcoSense High Efficiency Power Direct Vent (ECORHE50).

I can't find any online reviews of either product (save one favorable review on HD's site).

For several reasons, I'm looking at a high efficiency storage water heater instead of tankless.

In Green products and materials | Asked By Michael Brahmey | Oct 11 14
Register for a free account and join the conversation


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