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8 Answers

Attic insulation upgrade

I'm struggling with getting the correct answer on how to proceed with upgrading my attic insulation.

I live in Pittsburgh PA climate Zone 5A.
My existing attic space has batt insulation on the floor with no air barrier and is vented at the gable ends.

I would like to spray foam on the underneath of the roof deck sheathing in-between the truss joists and on the gable end walls to meet the required R38.

I'm struggling to understand if I should use open cell foam or closed cell foam.

In Green building techniques | Asked By Forrest Watson | Sep 1 15
2 Answers

Ducted mini-split serving multiple floors

I am attempting to break my house design into zones such that I can use one mini-split for each zone. I am having trouble simultaneously satisfying two pieces of advice from this forum. In "Rules of Thumb for Ductless Minisplits," Martin says that one ductless head can serve a maximum of about 1100 square feet. That is based on distribution, not capacity. I realize that it is a rule of thumb that might not apply to a super-open floorplan, but if I violate that rule, I should have some justification.

In Mechanicals | Asked By Reid Baldwin | Sep 2 15
2 Answers

How were the IECC Climate Zones maps developed?

Were high resolution zone maps developed and then adjusted to match the county boundaries—perhaps with a generous safety margin—or something different entirely?

My brothers' houses, 150 feet apart, are in different counties. One house is in Zone 3 (Johnston County, NC), the other in Zone 4 (Harnett County, NC). Should my Zone 3 brother be concerned that he's really experiencing Zone 4 conditions (and vice versa)?

A generous safety margin might imply that some true zone 3 climate locations are well into Zone 4 map areas which can have a large impact on those with a tighter budget.

In General questions | Asked By Stewart Akerman | Sep 2 15
22 Answers

Skipping radiant floor heat in a passive house?

I'm building a house with (conservative numbers) R 60 walls and R90 ceiling. The windows are in-swing casements with double seals. The floor is going to be stained concrete on 2" insulation. I had 2 consultants tell me that I will not need radiant floor heat it will be too much. We will have a whole house air circulation system and a gas fire place. I am worried about not putting in the pipes in the floor and then being wrong. I am considering just putting in the heated floor under the rooms away from the fire place. I could add a heater to my whole house ventilation system if needed.

In PassivHaus | Asked By Jenz Yoder | Aug 25 15
5 Answers

What mechanical system makes the most sense?

I am in a zone 4a Kansas City Missouri. In the heat of the summer it can get up to 95 with high humidity and it doesn't cool down at night.

We are building a 3500sqft ICF house with R-24 walls. (We have the labor and resources for it to be the most affordable option) and a R-60 SIP roof, cathedral ceiling. We are thinking about building with a 4' crawl space, unvented, 20 mil vapor barrier. Our windows and doors we are sourcing from company's in the U.S. which build to the PassivHaus standard.

I have a few questions:

In Mechanicals | Asked By Jordan Schiele | Sep 2 15
4 Answers

How to reduce the humidity in my home?

I live in a 1200 sq ft. mobile home and heat with electric space heaters. I do not tolerate forced air due to severe chemical sensitivities (it is propane), so all grills and ducts are blocked off. The humidity in my home runs between 40 - 50 % which is too high. I keep it closed up tight to keep out wood smoke and dryer sheets from the many close neighbors that I have. I am interested in the eGO for my laundry room, and wondering if the air coming in and out can be filtered with more than what it comes with. I am also open to other suggestions.

In General questions | Asked By Suzanne Lippuner | Sep 1 15
1 Answer

Seeking advice on insulation and membranes for an exposed wood structural roof

I am working on a little house extension located in Toronto Canada. We are shooting for an exposed wood structure, with the insulation (required r-value 31) outboard of the roof's diaphragm which will either be tongue and groove or a very thick plywood.

I am very unclear on where my vapour barrier should be located - I was taught that the membrane needs to go on the warm side of your wood studs, in a conventionally framed wood house. In this scenario there is nothing below the warm side of my structure at the ceiling - there is analogy in the condition I am working on.

In General questions | Asked By Guy Debord | Sep 1 15
10 Answers

I am considering getting solar panels on my roof

I am considering getting solar panels on my roof and have quotes from 2 different companies. Is there anywhere I can go to get help on determining which are the better panels?

In Green products and materials | Asked By Dave Sanda | Aug 31 15
2 Answers

Damp spray cellulose in Los Angeles

Does anyone have a recommendation for a damp spray cellulose installer in the Los Angeles area?

Also, out of curiousity what is the going rate in your neck of the woods for damp spray cellulose (2x6 wall)?

Thanks in advance

In Green products and materials | Asked By Jack G. | Nov 4 12
10 Answers

Comments on wall design, please

Attached is an image of a wall system I've conceptualized. It combines ease of interior electrical, plumbing, and wall finishing work with the structural benefits of CMU construction, the air tightness and performance benefits of a REMOTE wall, and the maintenance benefits of EIFS.

Looking for feedback. Any pitfalls with this approach? Overkill?


In General questions | Asked By Matt Culik | Aug 31 15
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