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14 Answers

What is the point of Passivhaus certification?

I see this come up often in cost analysis discussions, but I fail to see how certification can be anything other than a sunk cost. Unless I have a completely wrong perception of the process.

Are there direct subsidies in some places?

If certification is done after the house has been built, how can it help you build a better house?

If certification starts with designing, why would passivhaus certifiers be any better then other people who measure air leakage and calculate necessary insulation etc?

Asked By Davor Radman | May 12 18
6 Answers

Improvements in high-R phenolic foam since the disastrous 1980s

So I have been reading about the closed-cell phenolic and noticed the recent blog describing the use R-8/in Kingspan Kooltherm phenolic foam board in a retrofit.

The unique ability of these phenolic foams to achieve high R-values upwards of R-8 per inch seems to be established in testing and experience. However...

Asked By Aaron Birkland | May 6 18
4 Answers

Existing basement framing against concrete

We are looking to insulate our concrete basement foundation walls and the 18" wood framed area between the foundation top and the bottom of the floor above it that includes the sill plate. We are settling on closed cell spray foam.

When the house was built the framing for the exterior basement walls were set up against the concrete foundation. There is anywhere between 0 to 1/4" between the studs and the concrete depending on the studs and the texture of the concrete forms.

Asked By tyman00 | Apr 11 18
10 Answers

Seal gap between felt paper and interior wall stud cavity?

Hi there,

I'm currently remodeling a house in Austin, and while I have the walls opened up from the interior, I wanted to know whether or not to caulk or use spray foam as a way to fill in the gaps between the sheathing material and the stud walls. In portions of the house there is felt paper for the areas with wood siding, and other areas there is thermo-ply for the brick walls.

Asked By homeowner123 | May 11 18
4 Answers

Roof ventilation for an L-Shaped (Plan) house with a shed roof

Climate: 4C (near Seattle)

I'm working on a 1-story home with an L-Shaped plan that will have a shed roof (low side of roof at the interior corner of the plan).
The roof will be constructed with trusses where one wing of the house would have a conventional attic but the other wing would have parallel chord trusses (~18" deep).
There will be a continuous soffit vent at the high and low sides of the roof for ventilation.

Asked By Daniel Stewart | May 13 18
3 Answers

How to insulate tiny hot roof

I live in Michigan. We just survived six months of snow. It's forecast to be 80 next week. Humidity in summer is very high. Those are the unchangeable factors.
I'd like to insulate the roof in my bedroom closet. The house went on the tax rolls in 1896, when insulation wasn't a big concern for the builder.
I had dense pack cellulose blown into the walls. A pro did the attic over the two-story part of the house; another company blew in cellulose into the roof of the 1 and 1/2 story part. All parts of the ceiling in that section are lath and plaster.

Asked By AZOgram | May 13 18
9 Answers

Residential peak demand questions

I'm sure most of us have read Dana Dorsett's comments on residential peak demand based pricing that is gaining interest from utilities across North America. Those comments always come up in other members comments so while I feel like I have several comments and questions I try not to derail another persons thread too much. I was hoping to start a thread about that subject so I could ask those questions.

Asked By Calum Wilde | May 12 18
4 Answers

Unvented vented roof with exterior rigid insulation

Hey All,

I am doing an energy retrofit on a Zone 5 simple box gable roof. Part of this calls for redoing the roof. I am sold on the exterior rigid foam idea to cut down on thermal bridging and also since my roof slope is very low and the eaves are shallow.

Code calls for R38 but I want to shoot for about R50. The planned assembly going upward is:

1. R20 of fluffy between upper truss cords
2. Structural sheathing with taped seams
3. Air barrier
4. First layer of 3" polyiso rigid foam
5. Second layer of 3" polyiso rigid foam with staggered and taped seams
6. Roof underlayment

Asked By jetlaggy | May 12 18
4 Answers

Attic insulation

Hi, My air conditioner doesn't keep the house cool enough in the summer. I live in SW Florida and the house was built in the 80's. The existing blown in insulation has matted down. I'm about to get a new roof. I'm hoping that if I seal the attic cracks plus add inslulation it may solve my problem. I've come across many options and not sure which/what to do, they include which insulation should I use, fiberglass or foam on the floor, should I put a couple of inches rigid foam insulation between the roof and the plywood and insulation on the inside ceiling of the roof between the rafters?

Asked By OntheWater1 | May 11 18
1 Answer

Attaching LP Smartside to ICF house

I'm looking for detailed information on how to install LP smartside on an ICF house. If anyone can help me out, the more information the better.

Thank you,

Asked By JBICF | May 12 18
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