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97 Answers

Unvented slanted roof with radiant cooling and NO polyurethane in 4C

We are in Everett WA, north of Seattle, right on the coast, zone 4C. I hope that our location will save us...
We have a low sloping steel, west facing roof. Double, 30 weight felt paper underneath to dampen rain noise. I presume 1/2" plywood sheathing. 2x12" rafters, 11" true depth.
We will install WarmBoard R (13/16" thick OSB with aluminum tracks) underneath the rafters for summer cooling and supplemental heating in winter.

In GBA Pro help | Asked By Jan Verschuren | Mar 11 15
10 Answers

Best way to find the experts in my area

What or where is the best resource to find the top green architects/designers and builders in my area?

In GBA Pro help | Asked By Mary Dorcey-Mussog | Apr 1 15
3 Answers

What suggestions do people have to solve a R-38 roof problem?

We are building a single car garage over a studio apartment in the western North Carolina mountains, Zone 5A. The garage level will be accessed by an 18' bridge. The project is being engineered to address the structural issues of both the bridge and a second level slab to support the car. At this point it appears that we will be building the lower level with Logix ICFs of varying dimensions up to 12" and the second level slab will be supported by 10" Insul-Deck forms. The slab will be 4" thick.

In Building Code Questions | Asked By Jane Greene | Apr 9 15
17 Answers

Is this design OK for my vaulted ceiling?

I am new to this. I feel like I am back in college researching like crazy and finding too much info. This is the best site I have found. Keep up the good work. I have built several houses, but this one has a vaulted ceiling covering a 34 X 34 space. (This is my daughter-in-love's request. How could I say "no"!) However, I am beginning to have second thoughts. This is what I have come up with due to a variety of reasons.

In GBA Pro help | Asked By Tooger Smith | Apr 8 15
11 Answers

HPWH (in garage) in series with Electric Water Heater (in house)?

Hello,

I'm hoping to get a sanity check before proceeding with my water heater plan for a house I'm building, located in central Oregon (zone 5).

My plan is to install:

1) 50-gal Heat Pump Water Heater (GE 50-gallon model) in unconditioned garage space

> connected in series to downstream >

2) 50-gal Electric Water Heater (50-gal super insulated Marathon unit) in conditioned space in adjacent laundry room.

Some reasons this seems to be a good setup in my particular situation:

In Energy efficiency and durability | Asked By True South | Apr 8 15
0 Answers

Announcing a useful new feature on GBA

It's been a long time coming, but GBA finally has a "Recently Posted Comments" page. We've been wishing for this feature for years... and now it's here.

To get to the page, just click on the words "Recent Comments" that appear in the small box to the right of the Rotator images near the top of the GBA home page.

In General questions | Asked By Martin Holladay, GBA Advisor | Apr 10 15
3 Answers

Is what my contractor telling me correct?

I have placed a contract for repair and insulation of flat roofs. A fibreglass finish to the roof.
The contractor stated that screws to hold the Xltratherm boards in place would not affects the insulation values also that fibreglass insulation compressed into 75mm rafters by 50mm Xltratherm boards is equivalent to 140mm of Xltratherm boards.

Is this a reasonable statement?

I am trying to discover how much if any degrading in insulating properties occurs when insulation boards are attached to roof beams by screws.

In GBA Pro help | Asked By MikeDunwell | Apr 9 15
2 Answers

Insulating an unheated, concrete walk out foundation

Building an unheated boat house -architect design lower level to be poured concrete and slab built into a hill, with 4th side open to a lake. Wood framed shed like structure above. I'm concerned about condensation in the summer so would like to insulate under slab and foundation walls, but what will happen to slab and foundation when exposed to ambient temps of NH's winter? Which is the bigger risk? Or insulate and Construct super insulated/tight doors?
I would appreciate any thoughts.

In Energy efficiency and durability | Asked By Margaret Dillon | Apr 10 15
7 Answers

Attic insulation advice/feedback

We recently moved into a 1952 Cape Cod home and will be remodeling the entire 2nd floor attic/living space so now is the time to get the insulation done right. As a result, I have been doing considerable reading on the topic of insulation and would greatly appreciate some advice on my current plan to “cathedralize” and insulate this space.

The plan:
Vent the soffits.
Create a 1 inch deep soffit to ridge ventilation channel in each rafter bay using .5 inch rigid XPS foam board sealed in place with caulk/spray foam.

In General questions | Asked By Chris Kolloff | Mar 18 15
23 Answers

Mitsubishi mini split behaving very differently with external thermostat vs. without

I am able to monitor my home's electricity use and I always thought it was a little weird that my Mitsubishi FE18NA heat pump seemed to constantly be spiking up and down, considering that the whole idea of the inverter-driven compressor is that it can run smooth and steady... fast forward to yesterday when I received my MHK1 thermostat and hooked it up. Suddenly, the power usage was steady as a rock.

In Mechanicals | Asked By Nick Welch | Jan 6 15
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