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5 Answers

Is this wall assembly okay?

I live in upstate SC in climate zone 3. It would be more like 3.5 if such existed. I'm about to build a house and the wall assembly I want to use is slightly different than examples that I have seen and I'm concerned about drying/dew point.

I plan to use 2x4 wall construction, wrap it with 2" of rigid Roxul abd 1/2" Zip sheathing with a brick veneer. My thinking is I have a standard 6 9/16" window/jamb width but I have also killed the thermal bridging.

In GBA Pro help | Asked By Chip Radford | Apr 26 16
1 Answer

Hip ceiling, kneewall insulation help


First off thanks for the extremely informative site. I'm picking up lots of information, but looking for advice.

I have a 1930 Bungalow, Zone 5 (coastal Massachusetts). Vented roof with 8/12 pitch, asphalt shingles (good condition), felt and plank sheathing, 2x6 rafters.

In Energy efficiency and durability | Asked By Ryan Silva | Apr 26 16
1 Answer

Double walls, dense packing, and bendy sheathing

Many articles on double stud walls suggest fiberboard or gypsum as the exterior sheathing to prevent winter moisture issues. Given that thick walls require higher cellulose density, what tricks are there to keep the sheathing from bulging?


Zone 5, Rochester NY

In Green building techniques | Asked By John Ranson | Apr 25 16
1 Answer

How to tie exterior foundation drain to sump pump

I have already formed my basement walls for an addition to the rear of my home. I stepped down the footings to get a bit more headroom in the new basement area. Due to lot-line setbacks i poured the footers to the full extent of my dig-out and now i am running my exterior french drain around the base of the foundation wall. My only option seems to be to run the drain to day light but that requires digging a rather deep and very long trench. Is there a way to tie the french drain into a to-be-installed sump pit and pump it out.

In General questions | Asked By Mike Donohue | Apr 25 16
6 Answers

Rainscreen at bottom of sliding door details

Hi guys,

I am currently residing my house. I have 1.5" eps foam, then Tyvek WRB on top. Then on top of the tyvek I have a rain screen (3/4 plywood strips) and will be using vinyl siding on top of that.

Attached are pictures of my sliding door. I was wondering if there were any details on how to flash the bottom of the door. As you can see in the picture I also have my outside trim in 3/4 plywood as well. I will be wrapping up the trim in aluminum trim.

In General questions | Asked By Dan Nospa | Apr 25 16
2 Answers

Does a 6-12 roofline mate up well with 12-12 roofline?

I've got a 2 story 26' by 32' cottage with 12-12 pitch.

I would like to add a 12' by 16' screened in three season to the gable side on the North side.

The Contractor recommends matching the cottage roof pitch (12-12)...

In General questions | Asked By Mark Conroy | Apr 25 16
34 Answers

Condensation on windows with steel SIP home

We built a steel SIP house this summer near Hannibal, MO. We've been very happy with the results with one exception. The builders used steel L-angle to wrap the windows on the outside in order to better square the openings before installing the windows. They also installed the windows. This steel angle is not thermally broken at all. One part of the angle lays against the steel panel skin on the outside, and the other angle extends past the window into the living area about 2".
We do not have siding on the home. We have left the exterior steel exposed.

In Green products and materials | Asked By Jeff Carroll | Dec 13 15
2 Answers

1:300 net free vent area ratio vs. continuous soffit vent

In the GBA article Lstiburek’s Rules for Venting Roofs (07-24-2011), he notes the importance of having continuous soffit vent so the entire under side of the roof gets air flow. Although he does not mention the 1:300 rule (in that particular article) he does talk about splitting venting 60% to soffit and 40% to ridge so the space stays at a higher pressure than the inside of the house.
I assume that we are suppose to still follow the 1:300 guidance for determining NFVA. BUT, what if running a continuous soffit vent means the ratio is going to be more like 1:150?

In Energy efficiency and durability | Asked By Jack Randall | Apr 24 16
9 Answers

Advice needed: Recycled XPS rigid foam

I've located 4x8 sheets of 3" recycled foam board. This is DOW blue board, claiming to be 3" thick.

Should I nab this up for exterior insulation around the foundation? The price seems right and I love to recycle.


In Green products and materials | Asked By Drew Baden | Apr 19 16
10 Answers

Straight line for laying blocks when it's too windy for string?

I'm about to start laying four courses of CMUs for the stem wall of a simple rectangular house's foundation.. It's been very windy here and will continue to be for another few weeks. On the one calm day we had, I projected the string lines for the outer edges of the house downward, drawing lines on the surface of the footing itself so that I would have a straight, accurate line when it's windy, but as I plop mortar down to lay each block in the the first course, those lines will get covered.

In General questions | Asked By Jeff Cooper | Apr 23 16
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