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10 Answers

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The Real Problem of Subsidies

In Energy efficiency and durability | Asked By aj builder, Upstate NY Zone 6a | Jan 11 12
4 Answers

In a recently completed home of our design, the contractor - a firm I'd not worked with before - convinced the client to use spray foam insulation for walls and roof instead of the cellulose I'd planned. Part of his justification for accepting lower-than-code R-value of the roof was that the Delta-T of a sprayed roof deck assembly would be lower than if the insulation were at ceiling level. He noted that the air temperature of a vented attic would be some 30° higher than outdoor air.

In Energy efficiency and durability | Asked By James Morgan | Jan 13 12
6 Answers

Hi Martin,

Thank you for your article on radiant barriers. I hope you can help me. I
have a (hot in the summer, cold in the winter 2nd floor) approximately 1,300
(about 650 per floor) sq ft Cape Cod on Long Island, built in 1956 w/2 x 4 16" oc construction. I have already re-insulated w/R-13, vapor barrier fiberglass and added new drywall to the 1st floor. The 2nd floor has 2 bedrooms separated by the stairs in the center of the house. The 2nd floor
has an attic or crawl space, behind the knee walls, and though recently

In General questions | Asked By Jeffrey Kolsch | Oct 24 11
3 Answers

A builder I am doing energy consulting with has used tech shield roofing material on the exterior walls. The foil is manufacturer perforated for moisture. Is this a good or durable application for this sheathing? Will it effect the wall system?

In Green products and materials | Asked By Bruce Glanville | Jan 12 12
1 Answer

I've got some plugs in the siding now that indicates blown insulation was used. I don't know if cellulose or fiberglass was used, but my walls are COLD. I have already talked to my siding contractor about 4 inches of foam board and a layer of house wrap. Would it be overkill to add additional insulation inside the walls either on top of the existing insulation or by removing and replacing it? Spray foam insulation is all the rage right now, but the cost is substantially higher than cellulose or fiberglass.

In General questions | Asked By Jason Schaffer | Jan 13 12
14 Answers

A friend of mine drylined his interior walls about 3 years ago. The wall construction is of concrete hollow block construction, rendered on the exterior with plastercoat to the interior face. Bear in mind this is a wet, windy, and cold climate.

This wall was subsequently insulated to the interior using 50mm (2") (Possibly EPS boards, but he was not sure whether EPS or fiberglass when I asked) insulation with 1 layer plasterboard over, then plaster skim coat to finish.

In Energy efficiency and durability | Asked By Tim O Brien | Jan 11 12
23 Answers

We are planning to build a 1250 sq. foot A-frame. The problem is the roof as the inspector is requiring R-49. We know we want it to be well insulated. But due to the roof actually being the walls also...insulating space is an issue. We have already decided to to 2x 12 rafters with 2 inch ridgid on the outside for the roof. Walls are to be 2x4 with again 2 inch ridgid foam on the outside. Has anyone used Protex? Also does anyone one know where to get reclaimed 2" inch foam in this area?

In General questions | Asked By maureen mcginnis | Dec 25 11
5 Answers

A supplier here in Ireland advocates the use of timber-framed walls using timber studs and insulation between 2 layers of plywood WITHOUT using any tapes or other adhesives to air seal the junctions..

The large prefabricated frames consist of plywood as the air barrier and silicone is used as the air gasket / adhesive squeezed between studs and plywood.

I have misgivings but is silicone used this way a durable and effective alternative to traditional fixing methods with tape at plywood junctions?

In Energy efficiency and durability | Asked By Tim O Brien | Jan 11 12
2 Answers

I read your article on your website "Calculating Minimum Thickness of Rigid Foam Sheating" and viewed the rigid foam installation video on YouTube with David Joyce. Thank you for having a great website and videos with lots of information.

In Energy efficiency and durability | Asked By Owen Nelsen | Jan 12 12
12 Answers


I have a tight house (2.0ach50p) and want to install a heat pump water heater in the heated basement. I have no back draft appliances and the house is all electric with a fully ducted HRV system. I occasionally run the range top fan on low and a bath fan for 15 minutes or less (timer switch).

In Energy efficiency and durability | Asked By Frank O | Jan 10 12
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