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11 Answers

Icynene & moisture

OK some of you may remember my previous question/story about Icynene, we now have more data and more questions;-)

Here's the beef:
I am removing Icynene OC foam from under the roof because it still stinks but here's something that's very odd.
It's a 1920s house with wood planks all over, a new metal roof installed right over 3 layers of self adhering premium underlayment.
Icynene was sprayed 6 in underneath deck to fill the rafter space about 1.5 years ago.
Now, here's what I measured.

In General questions | Asked By Don J. | Apr 1 13
15 Answers

Issues or success with rigid insulation under strip footing

I wonder what experience anyone has had with installing rigid insulation under continuous strip footings supporting a standard concrete foundation wall.

In Green building techniques | Asked By Kim Kornylo Walton | Mar 26 13
2 Answers

XPS interior closed cell roof insulation (DIY)

Quick question for you building experts!

It's a 1920s house with wood planks all over, no vents no plywood, a new metal roof installed right over 3 layers of self adhering premium underlayment. No gaps no venting.

I bought 2 in XPS from HD, cut it and placed under roof deck between rafters. Left 1/2 in gap around and used Great Stuff to spray around it and sealed it.
Actually this method appeared quite easy and it's much quicker to do than I thought once I figured out how to do it efficiently. It takes me about 20 minutes per rafter. Should have done this long time ago....

In General questions | Asked By Don J. | Apr 1 13
2 Answers

Crawlspace foam board and fire code?

When installing rigid foam in an unfinished crawlspace, what is needed to have it comply with the fire code? Foam board to be installed on inside of foundation wall and on the underside of joists?

In Building Code Questions | Asked By Dennis Dipswitch | Mar 31 13
22 Answers

How can I insulate an exposed flooring system properly?

hi,. i have an addition on my house thats aproximately 11x14 on piers and 5 ft off the ground over sandy soil and exposed on all sides.It has a 2x8 ,16" on center floor system framed lengthwise over 2 , triple 2x10 beams, one for each set of piers.The subfloor is 3/4 tongue and groove plywood and i will be installing prefinished 3/4 x 2-1/4 tongue and groove strip oak flooring.

In General questions | Asked By mr. mike | Mar 24 13
4 Answers

Sealing rafter bay / ceiling of exterior wall

I am sealing a cathedral ceiling with rigid foam, the "cut and cobble" method.

I think I read about sealing the ceiling of exterior walls because of pressure from below, but am unsure.

The attached photo shows the space between a rafter bay. Currently, I am applying foam between the rafter bays, attached to the roof sheathing, sealing with caulk or Great Stuff.

In General questions | Asked By Erich Riesenberg | Mar 29 13
9 Answers

Flanged or undersill mounted passive house windows?

I will be using Intus Eforte windows in my passive house build. I have the option to purchase flanged windows that are installed on the outer of my double walls, or an undersill application that mounts almost between my double wall assembly. What are the pros and cons to these two options? Thanks.

In PassivHaus | Asked By Matthew Michaud | Jan 1 13
2 Answers

HVAC in unconditioned space - backdraft dampers?

We have a 1000 square foot tract home in Walla Walla WA. (Yes, there are onions), The furnace , air handler, and ducts are in the attic. As a result, every cycle of the system sends cold air in the winter and hot air in the summer, until the conditioned air fills the ducts. Even worse, the ducts thermosiphon air in the winter, dropping cold air on us at night.

In Mechanicals | Asked By Kathy Reynolds | Mar 28 13
6 Answers

When is a plumbing home run a home run?

We are building a new home and are doing the plumbing supply lines with PEX tubing, a manifold system, and home runs from the manifold to each individual fixture.

The plumber has run the PEX lines, but was unsure where to mount the manifold in the mechanical room. So to save PEX tubing, he cut the PEX short, and plans to splice on whatever additional length is necessary to reach the manifold.

In Mechanicals | Asked By Roger Normand | Mar 27 13
11 Answers

Insulation advice please

I'm somewhat confused on the whole insulation issue. I'm working with an engineer on a 2,500 sq. ft. home in Truckee, Ca (Sierra Nevada, 6,000' elevation, 210 lbs psf snow load: Wall construction will be 2x6 on 16" centers. This is a cold climate:Zone 5, I think. Mostly dry in the summer, very little rain, precipitation mostly snow.

We are still in the planning stage. I want the house (my primary residence) to be well insulated: Walls R-24/R-25, Attic R-49, Sub-floor R-38 are my targets.

In Green building techniques | Asked By Earl Smith | Mar 26 13
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