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8 Answers

Insulating cold floor, keeping plumbing serviceable?

I have a question about a situation that a relative has encountered. Zone 5 (SE Michigan), an addition has been added to an old house. The addition has an exposed floor on piers, built with trusses. There is some pink batt insulation near the top of truss cavity, and two inches of foam (XPS) covered by plywood at the bottom. The problem is that the (pex) plumbing which runs from main house and then along bottom of floor has frozen up repeatedly.

In Energy efficiency and durability | Asked By andrew c | Aug 15 14
8 Answers

Blower door disappointment and questions

We had our final blower door test and it wasn't what we had hoped. Our initial cfm50 was 98 with windows and door and all the sheathing done so I expected a substantially better result with insulation and the smart vapor barrier. Our result was 220.

Obviously the higher air leakage has to be from penetrations after the building envelope was finished - vents mostly, I figure.

In Green building techniques | Asked By Lucy Foxworth | Aug 14 14
2 Answers

For energy efficiency, when should windows be opened for overnight cooling?

We have a 2 story home with air conditioning in the Chicago area. In summer, we've done several things to improve our energy efficiency. Our a/c doesn't need to run during the day, even on the hottest days. The interior temp rises gently up to 76-80F and, if needed, the programmed thermostat causes the a/c to run overnight (to 76F) when electricity is cheaper. If we know tomorrow will be 85F+ we set the overnight set point to 74-75F temporarily. It's always cooler at night but the temp varies. On hot days it may be a low of say 75-80F overnight. On warm days the low may be 65-70F.

In Energy efficiency and durability | Asked By w d | Aug 14 14
6 Answers

Foam board between studs and exterior sheathing?

Someone in my area which is located in a zone 5 recently built a small house and sandwiched used 2.5" polyiso between the studs and the exterior wall sheathing. At first I was skeptical but still intrigued. It certainly simplifies window details compared to foam on the exterior. However I guess you would loose some structural rigidity. But would you really loose that much? If the wall sheathing is screwed on over the foam, the friction of the foam against the studs alone should help keep the wall from racking.

In Green building techniques | Asked By Dillon Vautrin | Aug 14 14
4 Answers

Ice Storage for residential cooling

We have a project in a 5a climate zone and another option for cooling that we are considering is an ice storage system (like Ice-Energy/ Ice Bear used to have) for residential cooling. It doesn't seem like this is available at the residential scale. We understand it is a more expensive system but we are interested in the CO2 reduction concept that this could allow. Any thoughts on this would be appreciated.

In Mechanicals | Asked By Nathan Kipnis | Aug 14 14
0 Answers

Insulation for a new build in zone 5

I’m building a brick bungalow in the northern edge of climate zone 5, and I’m trying to decide on insulation for my main floor. My drawing calls for 1” (R6.5) rigid insulation (polyiso) mounted directly on the 2x6 exterior main floor studs, then batts and poly in the bays. Instead of the batts and poly, I would like to do cc spray foam with no interior VB and just drywall with latex paint. Is it okay to spray the inside face of the polyiso? I’m concerned about the heat created when spraying, the vapour permeability for inside drying, and the possible double VB.

In General questions | Asked By Jeff Conners | Aug 15 14
2 Answers

Exterior rigid foam details/concerns for roof

Finally am at the point of redoing my attached Ell roof on my 200+ year old colonial.
This is what I currently have.
Zone 5

Inside 3/4 inch pine (obviously very air leaky) cathedral ceiling, Behind that it appears to be a foil faced fiberglass. Prior owner did this some time in the 80's. The sheathing is 1 x 10 running from peak to soffit ( again very leaky). There are 2 layers of asphalt shingles, then a 1 inch layer of Styrofoam insulation board with another layer of asphalt on top of that. Fun Fun!

In Green building techniques | Asked By terry grube | Aug 14 14
4 Answers

Insulate roof with foam panels on top instead of blow-in insulation

I have a 1000 sq ft single story house in the SF Bay Area, and I'm paying hundreds of dollars a month to run the central AC and a window unit. And even then on hot days it sometimes gets up to 80ºF inside. Ducts run through the uninsulated "vented" attic (only vents are two holes at the gables).

In General questions | Asked By jim brooks | Aug 12 14
17 Answers

How can I be sure our contractor installed insulation correctly?

Recently our contractor indicated he was complete with the insulation installed with cellulose in the existing walls at our home and wanted a signoff for customer satisfaction. Our home has cedar shingles, tar paper and pine tongue and groove sheathing. He removed the outer shingle and drilled through the tar paper and pine sheathing to install cellulose. THen he installed a styrofoam plug and put shingles back over. However, my husband was concerned that the area that was drilled and then filled with styrofoam may have moisture or leakage.

In General questions | Asked By Katie Nunez | Aug 10 14
0 Answers

Residential Desiccant Cooling

We are designing a house in a 5A climate zone and am wondering if anyone has any experience using a desiccant wheel system for residential cooling?

In Mechanicals | Asked By Nathan Kipnis | Aug 14 14
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