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7 Answers

Can I install 2"-3" of concrete in a 6" exterior wall?

The exterior walls on the house are 6" wood frame. I want to insulate the walls either with 2" or 3" of insulation and leave enough space for 2 1/2" to 3 1/2" of concrete. The concrete will only be poured to about 6' above the floor with the taller remaining space on the 9' walls to be 5 1/2" of blown insulation. Can I sandwich the cement between 1 1/2" sheets of extruded polystyrene? Will moisture weep on the inside surface of the cement in cold weather?


In General questions | Asked By Wayne McConnell | Feb 5 14
1 Answer

Combined gas and wood smoke vent?

Can I join a wood smoke vent pipe with an existing vent pipe from my gas central heating unit in the attic so I have only one vent through the roof?

I would like to install a wood burning stove and the vent pipe through the ceiling into the attic is on approximately the same line as the existing vent pipe from the central heat unit in the attic and already vented through the roof. It would be nice if I could just tie into the existing pipe in the attic so I don't need to cut a separate hole right next to the one already there.

In General questions | Asked By Lloyd Walker | Feb 7 14
2 Answers

Thermofoil - any info?

I keep running across Thermofoil cabinets that are touted as "green" because of their durability yet it's made of vinyl and glued onto (not necessarily NAUF nor FSC certified) MDF. Do you have any info/opinions?


In Green products and materials | Asked By Bettina Hoar | Feb 5 14
2 Answers

Flash-and-fill double-stud walls?

After reading the Building science article regarding moisture monitoring in high R value walls:


I became interested in the idea of a flash and fill double stud wall. (new construction climate zone 6 - northern New England) as a "safe" wall for my location.

In General questions | Asked By Christopher McKay | Feb 7 14
6 Answers

Exterior roof sheathing ventilation

I am designing a 2,000 sf [pretty good passivehouse] house in Colorado. The site is in Zone 7B, 10,000 HDD; -16 Design Temperature @ 8500' elevation, in other words, damn cold.

We are implementing most, best building practices where practical for this budget [current energy model at 21,000 BTU/hr]. We will have interior and exterior air barriers.

In Green building techniques | Asked By Tim Van Meter | Feb 3 14
5 Answers

Adding ceiling insulation...

My son's house has R-38 fiberglass batt (12") above the bedroom ceiling. There is vented attic space above that. While the R-38 may be a decent # in theory (though R-50 would probably be the current zone 6 amount), I'm thinking the air sealing capability here is slim to none (below batts is the kraft facing stapled to joist bottoms and 1/2" sheetrock.

In Energy efficiency and durability | Asked By Howard Gentler | Feb 5 14
1 Answer

DC lighting in the home?

We are a custom builder in Austin, TX and wanted to ping the community to see if anyone has any experience with dedicated DC lighting distribution in a residential application? Our feeling is that it is where we will inevitably be going in the near future as the benefits are endless ranging from improved efficiency to better dimming -ability in lights. Right now we are only doing this in recessed cans, running all 12V LEDs from a centralized transformer, or directly from a battery+PV application.

Any range of discussion would be great!!

In Green products and materials | Asked By Michael Alwan | Feb 6 14
7 Answers

Who sells mineral wool board near Boston?

I was just told by a large north-of-Boston lumberyard that stocks Roxul products that they can't get any of the Comfortboard IS products in less than half-truckload amounts.

Who is stocking this stuff near Boston? I am hoping to use mineral wool instead of foam on a project this spring, but I'll need 200 sheets max, not 1000.

In Green products and materials | Asked By Eric Peterson | Jan 31 14
4 Answers

Energy-efficient double entry door

Living in Europe one would not have this problem as we have here in the USA; that is finding a good energy-efficient double door.

I need to find a 3'- 0" x 7'- 10" (double door), total 6' width. I can get a French door but I don't want all glass. I am looking for a nice wood door with an EPS core and excellent double or triple gasket sealing capabilities with European hardware and multiple latching mechanisms for tight air sealing.

Any leads?

In Green products and materials | Asked By Peter L | Feb 5 14
3 Answers

Basement / crawl space fix

I'm doing a renovation on a house that is half crawl space and half basement. The crawl space is part of the original house (circa 1950) and involves a concrete footing with a pressure treated knee wall built on top of it to support the floor joists and above wall (and the rest of the single story house). It is skinned with PT plywood and backfilled to a depth of about 4 feet with the local silty dirt. It was insulated with pink fiberglass batts and had an interior vapor barrier.

In GBA Pro help | Asked By Ashley Lubyk | Feb 4 14
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