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1 Answer

Vented metal roof and underlayment

Hi Martin,

We're planning on installing a metal standing seam metal roof over an existing vented cathedral ceiling. In zone 5, the existing conditions to remain are gyp. board ceiling and fiberglass batt insulation between the rafters.

After removing the existing cedar roof and skip sheathing the contractor installed plywood and an impermeable (less than .02) high temperature self-adhered membrane over the whole roof.

Will the impermeable membrane create a situation where the plywood can't dry out?

Please confirm we should still vent the assembly at the soffit and ridge.

In General questions | Asked By S G | Jun 16 17
2 Answers

Why is the "Green Homes" section blank?

When I click on section tab at the top, the page that I'm directed to is blank!

In GBA Pro help | Asked By Cm Mm | Jun 15 17
8 Answers

Cathedral ceiling insulated with batts?

We finally received quotes back to insulate our cathedral ceilings the way I thought was best after a lot of reading on this forum. It is insanely expensive.....Just to preface-I wanted to use continuous baffles with dense packed cellulose/fiberglass. I was trying to limit spray foam in my house not only due to cost but other factors....

In Green building techniques | Asked By user-6816910 | Jun 13 17
3 Answers

Heating and cooling second floor with mini-splits wall units versus mini split ducted

I am updating the heating and cooling system in my home. My second floor consists of 3 bedrooms with a bathroom. I am struggling deciding between a ducted mini-split system versus mini split with wall units for each bedroom.

In General questions | Asked By sbrady46 | Jun 14 17
6 Answers

Attic spray foam alternative

I have been considering having the underside of my roof spray foamed in the attic. I've done the BTU/hr heat loss calculations (designed for 68F indoor and 0F outdoor), and the payback in BTU/hr for each additional inch of closed cell foam really starts falling off after the 1st 2 inches which are needed for a vapor barrier to prevent condensation. The roof above my attic is only about 1044 sqft (simple gable roof), which is at best only 50% of the surface area of my house (i.e. ceilings and walls) that is exposed to outside temperatures.

In Energy efficiency and durability | Asked By thomase00 | Jun 15 17
16 Answers

Interior impenetrable membrane for SIP roof and floor panels

I'm in the detailing stage of my cabin and need some advice on air/moisture sealing of the SIP panels. The panels (12 1/4" from Insulspan) willform shed roofs and the main floor only (the walls are 2x6's with Roxul Comfortbatt insulation, interior Membrane barrier with 1/2" drywall, exterior 1/2" plywood sheathing, Stoguard, 2" Roxul Comfortboard, 1 x 4 furring and then LP Smartside cladding). Inside the cabin there will be an 8" deep false floor built within the exterior walls to run plumbing and electrical.

In Green building techniques | Asked By Scott Wilson | Jun 5 17
20 Answers

Retrofit single ductless minisplit to cool entire upstairs

Hello, I'm a huge fan of this website, but I finally joined so that I could ask this specific question:

My wife and I own a 2000 sq-ft colonial built in 1962 in the Metro Detroit area (climate zone 5), with only baseboard heating--no central air. The first floor can be kept comfortable with a single wall-mounted AC unit and some fans to help circulate, but the upstairs is a bigger challenge. We've had several options quoted to provide some form of AC, but we're leaning strongly towards a ductless minisplit system.

In Green products and materials | Asked By Nathan Efrusy | May 9 17
9 Answers

Housewrap under rigid foam AND taped rigid foam at windows

the set up: Climate Zone 3. I'm using a standard house wrap between the OSB sheathing and the 1" rigid foam. The rigid foam will have all seams taped and will act as the primary WRB behind 3/4" vertical furring and lap siding. The Question : How do I terminate the house wrap at windows? just bring all the way into the "outtie" window bucks (caulk to buck), install rigid foam, then install window peel and stick flashing on bottom/part way up the sides. Install window. Would you recommend a 2nd layer of house wrap around the windows? Attached to the rigid foam?

In Green building techniques | Asked By Inger Peters | Apr 17 17
17 Answers


Hey everyone, I'm new here, so please bare with me if I missed something.

After reading this forum for a little while, I'm convinced that doing things right (particularly insulating) is not a question anymore. Me and my fiance just bought our first house (Northern NJ) and need to replace the roof. We got a couple of quotes from the local guys, but most did not react too well when I asked about insulating the roof. GAF does not recommend it, or it is not necessary (one guy said R25 value in the attic is plenty for our area).

In General questions | Asked By Eldarchik | Jun 14 17
4 Answers

Add on demand to boiler system

We have a baseboard hot water boiler that is also used to heat our DHW(built in 1988). Seems we have larger than average gas bills even in summer. I have noticed that the boiler comes on even after 1 shower.
I am not sure if the temp set points are too low, boiler needs inspection, or to eliminate the side arm from boiler to DHW( Then add an on demand water heater). Bill over $100 mth seem very high for 2 people.

In Mechanicals | Asked By Bill Skaff | Jun 15 17
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