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13 Answers

Basement walls

I am building a ranch home and most of the basement (2800sqft) will be finished as living space. The builder has the waterproofing membrane spray on the outside of the basement, the plan calls for 2x6 with r21 insulation batts, and a certainteed membrain. There are drain tiles on the interior of the basement walls and the exterior. There will also be 10 mill poly underneath the basement slab when it will be poured.

Asked By D L | Sep 9 15
2 Answers

Flat roof — sloping and insulation

I own a custom 2-3 story hillside 3300 square foot island home in Gig Harbor, WA (Climate Zone 4C) that was built in 1972. I am the second owner and purchased the home in 1986. The house roofing consists of 80% metal on a 6:12 pitch and a 20% flat roof (~560 square feet) over the bedroom wing with eight ceiling can lights adjoining clerestory windows. The house plans specify R-19 fiberglass batt insulation. The flat roof was replaced in 2001 with a ridge vent and torch down installed.

Asked By Mike Hirko | Sep 11 15
6 Answers

Unvented roof, Zone 3B, foam-free

Hi Martin,

First off, I have read a wealth of articles on the subject of unvented roofs, by yourself and Joseph Lstiburek. I started with your “How to Build A Cathedral Ceiling” article and read pretty much everything related to this from you and Lstiburek. The conclusion being that for an unvented roof you either install closed-cell spray foam between the rafters, or rigid foam above the sheathing at a thickness dictated by your climate zone to keep the sheathing warm enough.

Asked By Joe G | Aug 26 15
5 Answers

New 20+ SEER Variable Carrier heat pump w/ Greenspeed Intelligence system creating moisture & performance problems in the crawl

I had to replace 2 -13 SEER HVAC split systems in my house about 2 years ago do to some Sandy storm damage. One split system was a 90% gas furnace with a 3 ton 13 SEER AC and the other was a 2 ton 13 SEER heat pump.

Asked By Bruce Howe | Sep 2 15
3 Answers

CMU walls and rigid foam

Retrofit concrete block walls painted inside and out. Exterior foam then rainscreen then siding. Keeping painted block as interior walls.
Do I have to be concerned with the vapor permanence of the foam?
Also, would there be any benefit in using foil faced...other than R-value?
Southern Georgia coast.

Asked By Robert Brown | Aug 29 15
15 Answers

Humidity control

I operate a facility where humidity control is very hard. The building is 6 yrs old, built well, but cant control the humidity. We have resealed return duct, replaced tstats, added attic exhaust fans, etc. But still the building humidity matches the outdoors as fast as it changes. We try to keep the building 72f and it feels like you can't breath and hot. Mildew forms. We keep the building 68f you can breath, but freeze and smells like a basement, and mildew forms. All exhaust fans are working, and ceiling fans are on.

Asked By clark jones | Aug 24 15
1 Answer

Furring strips or another layer of sheathing over foam?

I am in the process of framing a house 2x6, 24”oc. The house will be sheathed and taped with the Zip system and 2-1” layers of rigid foam (staggered seams and taped). Over top of the foam, I planned on using 1x4 or ripping down ¾” ply for furring strips to both hold the foam and attach the vinyl siding too.

Asked By Brian McDonald | Aug 27 15
2 Answers

What is your opinion of the CERV HRV system?

Looking to add an HRV to a new home plan, 2500 sq.ft.

Concerned with humidity levels in Massachusetts. Very humid summer. Dryer winter. House will be close to net zero.

Asked By Joseph Isherwood | Aug 26 15
2 Answers

What can I do to address a condensation and mildew issue on a cathedral ceiling?

Our house is 35 years old and has a cathedral ceiling in the living area located in the center of the house. We have never had an issue with the ceiling until about 5 years ago. Condensation develops during the summer months on the ceiling and ultimately results in mildew that spreads across the entire ceiling. We live in LA and the heat in the summer is in the 90s during those months. Approximately 8 years ago we replaced the roof on the house, using the architectural shingles and removing the power vents and replacing them with a ridge vent system.

Asked By Susan Cochran | Aug 24 15
3 Answers

Rain screen at soffit detail

CMU house in zone 2.. Hot/humid. Unvented conditioned attic, Rigid foam around rafter tails to underside of roof decking. Cedar shingle sidewall. Verticle and horizontal furring for rainscreen.
Here's the question: There is a plate at top of the wall but due to the slope of the roof the horizontal soffit line falls below the plate line. For added support I would like to run the verticle furring up to and attach to the top wall plate. This means the top of the rain screen will terminate in the unvented soffit.
Do I need...and how do I accomplish ....the top rainscreen vent. Thanks

Asked By Robert Brown | Aug 24 15
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