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5 Answers

Building Science Class

I was talking to Dr. Joe the other day and he made us an offer we could hardly refuse. He wants to give a class on Renovation and Restoration open to GBAGreenBuildingAdvisor.com PRO members only. He's also offering a 10% discount off the normal price ($395), making the price ($355). We are thinking sometime in June.

If you'd be interested in attending this class, please click through this link and check the appropriate box -- we want to gauge interest to see how big a room to get.


In General questions | Asked By Daniel Morrison | Feb 10 12
1 Answer

Can a combination of blue Dow board plus blown cellulose work well in an attic?

I live in zone 2B and have an old house with no insulation in the attic. I have no wiring, plumbing, or ductwork in the attic and it is unvented. Advised to spray open cell foam on the attic floor between ceiling joists (2X4 on 24 inch centers). Was hoping 3 layers of blue Dow board with foam around edges between joists to air seal space and provide moisture barrier and then loose blown cellulose on top might work almost as well but for less$$. Please advise.

Paul in Texas

In GBA Pro help | Asked By Paul Hanslik | Feb 10 12
1 Answer

How safe is Icynene spray foam to use in the ceiling of bedroom/bathroom addition?

Central coastal California area. The addition is on the north side of the existing house. I want to know the environmental hazards and the human hazards that may exist. The room has a vaulted ceiling and the area is 7 1/2" deep. The proposed agent is LD-C-50 ICYNENE spray foam.

In Green products and materials | Asked By mondra randall | Feb 10 12
3 Answers

Vapor barrier on ceiling?

We are building a new home in NW Montana, zone 6. We have a great room with a vaulted ceiling and a vented roof above. Going to use cellulose to r49 above great room. I want to make sure that I get the ceiling profile right. I have been told to put poly on ceiling then osb or plywood and lastly the metal we want to use for the interior finish. Will this work without causing moisture problems?

Any draw backs to using metal roofing on the interior ceilings as finish?


In Energy efficiency and durability | Asked By Rod Cleveland | Feb 10 12
4 Answers

Glazing options for Zone 3

We are trying to decide on window glazing options for our east facing windows in San Francisco. Our window manufacturer uses Cardinal glass and offered us two Low-e options.
Low-e 277 and Low-e 180.

In Energy efficiency and durability | Asked By Donovan Corliss | Feb 9 12
4 Answers

Flashing Details for Panel Siding

I am wondering if anyone has any advice on properly flashing window and door penetrations when using a panel type siding. My specific project specifies LP Smartside reverse board and batten siding in 4x8 sheets. The windows and doors are aluminum clad, with a 1x4 picture frame trim detail.
I am mainly concerned about the detail at the head, where it should be flashed. I would like to avoid just cutting out a hole in the panel for the trimmed and flashed unit, then relying mainly on a caulk joint, but maybe properly detailed, this is the simplest option.
Thanks for any help.

In GBA Pro help | Asked By Pete Archer | Feb 9 12
9 Answers

Retrofit insulation

Hello to all,

Well here is my conundrum. I live in a house that was built in 1983, and it was built using the minimum materials in every aspect. The house is a modern/contemporary with vaulted ceiling up to 28' high. Saying that the roof was framed using 2x8 rafters, and yup r-19 insulation faced bats. The walls are 2x4 with what seems to be at best 4 mil vapor barrier, r-11 unfaced bats, and 1/2" Celotex w/5/8" t-111 exterior siding.

I need to bring the r-value up to as (close) to minimum code. Our local code call for r-38 ceiling, r-19 walls.

In Energy efficiency and durability | Asked By jason hood | Feb 8 12
4 Answers

Mold is becoming the biggest health concern in the eastern US. Does building with Hebel block minimize or eliminate mold growth?

I am looking for a very energy efficient way to build a house and to avoid all mold issues inherent with plastic wrapped houses that can't breathe. Living with mold greatly increases symptoms of Lyme disease.
Got any suggestions?

In Green building techniques | Asked By Margery Brache | Feb 8 12
3 Answers

Why mechanically fasten sump pumps

What other reasons to fasten down sumps?
1) Reducing moisture vapor in basement
2) Air infiltration into house through any holes
3) back flooding into basement

In Energy efficiency and durability | Asked By Rick Jenkins | Feb 9 12
10 Answers

Relative importance of embodied energy?

I read this case study by David Fridley of Lawrence Berkeley National Laboratory:

Then I remembered one of Martin's blog entries:

The case study indicates that when evaluated on a annual basis, the embodied energy of a residential building is roughly equal to the energy consumed for its operation. The case study assumes a 30 year life-span for these buildings which is average in China.

In General questions | Asked By Lucas Durand | Aug 21 10
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