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9 Answers

Most cost-effective method for achieving 3 ACH 50?

What are your strategies?

In Green building techniques | Asked By Nick Sisler | Sep 17 14
6 Answers

Tudor half-timber battens and exterior stucco — rainscreen assembly

Hi, I am having a house built in a Tudor style.
What are the effects of Tudor half-timbered battens on a stucco's rainscreen layer?

The lower half of the house will have a stone exterior.
The upper half will have a stucco exterior.

I have read the article “To Install Stucco Right, Include an Air Gap” and understand the importance of having a ventilated rainscreen gap in the stucco assembly.

In General questions | Asked By Ani Brown | Sep 17 14
6 Answers

Has the Oak Ridge study on convective heat loss in blown fiberglass been updated to cover newer materials?

I'm evaluating blown cellulose vs. blown fiberglass (Knauf Ecofill). The Oak Ridge study is often quoted regarding the drop in R-value of blown fiberglass when the temperature differential is high. However the tested fiberglass density (.4 - 5 lb/ft^3) is much lower than the newer fiberglass.

In Energy efficiency and durability | Asked By Neil Weinstock | Jul 21 14
12 Answers

I'm wondering if you can insulate the attic roof rafters

Thanks everyone for your insight. I think the thing I've learned is that if your not going to finish the attic area and the walls to the finished room are insulated you don't have to insulate the roof joist, but you do need to insulate in between the floor joist and the finished walls.

In our doormer, There are two small doors going into the attic area from a finished dormer area, and the walls that are finished have batting. The floor joist in the attic have old blown fiber glass that has settled, so we need to fluff it up or add to it.. Thanks so much everyone.

In General questions | Asked By kristin burton | Sep 12 14
7 Answers

Better choice of exterior wall construction for new home?

We're building a new home in central Iowa. We're in climate zone 5. We thought we had a final above grade wall spec. Now, we're entertaining a different one. I think the first one is more robust, but I'd like an opinion on the two walls:

Wall 1 from inside to out:
1/2" drywall with latex paint
MemBrain "smart vapor retarder"
2x6 wood stud, 16" o.c.

In Green building techniques | Asked By Silas Hoeppner | Sep 16 14
12 Answers

Should my indirect hot water heater have a mixing valve?

I have a 2300 square foot colonial, built 1960 in Massachusetts (Zone 5A), with three zones of fin tube baseboard. There's a 75 gallon whirlpool tub which we almost never use; the two showers are fairly low-flow. Heat loss done by Comfort-Calc.net was 55,840. I use town water, which is very good quality (Quabbin reservoir). I've accepted a bid to replace my heating system with a Lochinvar WHN-85 boiler and SIT40 indirect water heater.

In Mechanicals | Asked By Daniel Griscom | Sep 15 14
7 Answers

Options for air sealing T&G ceiling with no air barrier installed

Hello all,
I apologize if this question appears a repetitive one, as I have read through a good bit of the Q&As here, but still cannot determine my best course of action.

In General questions | Asked By Rob Leonard | Sep 14 14
5 Answers

Effectiveness of Roxul "flash and batt" - irregular closed-cell spray foam causing air gaps?

I have a spray foam crew coming Thursday to convert my attic to "unvented" (2x8 rafters). They want customers to do 5". My plan though was to do 4" and then 3.5" Roxul batts to fill followed by a layer of the Roxul board to reduce bridging on the rafters.

In Green building techniques | Asked By Chuck Swanberg | Sep 16 14
4 Answers

Trying to determine best assembly to insulate an old church roof being converted to office

We are looking to keep the existing roof decking and rafters exposed in a church in Atlanta, Climate Zone 3. We have read Martin Holladay's FHB Article about unvented, Super Insulated Roofs, and Joe LUtiburek's article BSI-036 Complex 3D Air Flows talking about the subject. One of the big differences (really somewhat minor) I see between the two recommended details is the best place to locate the fully adhered air barrier. Martin shows placing it at the outermost layer right on top of the new sheathing, right below the roofing material. In this case asphalt shingles.

In Energy efficiency and durability | Asked By Eric Kronberg | Sep 16 14
4 Answers

Sill slope? Sealant tape?

How much slope is recommended for window sills? The house isn't in an coastal or otherwise very exposed location, but isn't in an arid or especially sheltered place either.

I'm planning on using beveled siding, placed on a flat plywood window buck, to help move water away from the opening; the exterior face of the window frame will be set about 4 - 5" back from the outside of the exterior sheathing. I'm trying to figure out how much extra room (vertically) to include in the rough opening.

In General questions | Asked By Graham Fisher | Sep 16 14
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