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6 Answers

Huber Zip system R-6.6 sheathing and minimum foam R-values

In zone 5 (central OH), the minimum R-value of rigid foam for 2x4 construction is R-5 and R-7.5 for 2x6 construction. What would be the required amount for a 2x4 staggered stud wall on 2x6 plates? Would the Huber Zip R-6 (R-6.6) sheathing be adequate since it would only be in contact with the 2x4 studs staggered to the exterior?

In Energy efficiency and durability | Asked By Milan Jurich | Mar 24 12
1 Answer

Is there value to radiant sheathing on South/West-facing walls in hot climate?

Is there any measurable benefit to installing radiant barrier sheathing panels (7/16" OSB) on vertical walls with a West or South exposure in a Southeastern climate? Of particular concern is the siding material ( 1/2" thick fiber cement shakes) which will seemingly act as an unintended heat storage device, continuing to radiate heat into the wall assembly long after sunset.

In Energy efficiency and durability | Asked By DENNIS MCKENNA | Mar 24 12
7 Answers


The energy auditor has just installed an HRV in our house. The blower door test was approximately 2.5. The HRV is installed in the attic with intakes from two of the bathroom fans. The intake is from the outside and after the HRV connects to the forced air return.

Here are my questions specifically regarding the HRV
1) How fast should the HRV run or how much air should it pull when its run continuously?

In Energy efficiency and durability | Asked By Kevin Hilton | Mar 22 12
3 Answers

Stair railings

Does anyone know where i can buy a book that contains math formulas for curved and offset stair railings?

In GBA Pro help | Asked By carl fields | Mar 23 12
7 Answers

Overwhelmed with Insulation Choice in NE Texas with a 3:12 pitch

We purchasing a 3000sf 1950's ranch style house in NE Tx. I really need your advice narrowing down the best insulation for us.

Problem: 3:12 pitch, no insulation and 2 wings of the house only have tiny access hatches that are blocked by ducts, and it needs a new roof in the next couple of years. Opportunity: we can seal up the openings and insulate it any way needed when we replace the roof.

In Energy efficiency and durability | Asked By Tonya McClelland | Mar 22 12
3 Answers

Dirt crawlspace insulation

I live in northern Minnesota. The house I purchased has a large bedroom, half of which is an addition to the house. It gets fairly cold in the room during the winter and I am looking at better insulating it. The addition portion has no slab or foundation under it. It was basically built as a fourseason porch with only footings. There is access underneath from outside with enough space for me to comfortably crawl underneath. It has dirt floor, batt insulation in the floor joists and a flexible/insulated heating tube going to the far end. No other pipes or wires.

In GBA Pro help | Asked By Nathaniel Hughes | Mar 22 12
4 Answers

Polyiso directly over Tyvek stucco wrap vs 1/4" shims between

I am a remodeler, project is my own whole house remodel in North NJ (Morristown - Zone 5). After reviewing your excellent information and blogs the envelope planned is:

In Green building techniques | Asked By Carlton Bruen | Mar 22 12
1 Answer

How to calculate Floor Insulation Effective R-Value

I have a 2x12 floor system with R-19 supported by spring wires every three feet or so. The insulation is 5" from being in substancial contact with the floor. What is the effective R-value and what publication can I point to for substantiation.

In Energy efficiency and durability | Asked By Tyson Pischel | Mar 23 12
8 Answers

EPS Foam on Exterior with interior vapor barrier?

I am gong to be re-siding my house (cedar) and am considering adding 1" or 1.5" of EPS foam on the exterior. My concern is that the current R13 insulation (2x4 walls) has a kraft faced vapor barrier. I know that I can't use XPS foam on the exterior because it is impermeable, but I know that EPS has a higher permeability, so I was hopring this would work and allow drying to the outside. I will be using a rainscreen over the foam. I am in Portland, OR which is in zone 4.

Would this work? Is it even worth adding the foam to an R13 wall?

In Green building techniques | Asked By David Fischer | Mar 10 12
20 Answers

Foam Under Monolithic Slab/Footing

Inspired by a recent blog post by Martin, I'm wondering if anyone has attempted to form and pour a monolithic slab/footing with foam at every facet, as depicted in the section sketch below. Pieces A and E are straightforward enough. Piece B calls for a lot of fussy smoothing at the bottom of the trench. Piece C looks like a serious pain in the neck to fit and hold in place. Piece D is a fantasy.

In Green building techniques | Asked By Ray Sten | Mar 15 12
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