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12 Answers

ZIP R-Sheathing Climate Zone 5?

I am considering ZIP R-sheathing for a home in Climate Zone 5. The wall assembly would be a ventilated rainscreen as follows (exterior to interior)

1. Hardie Panel siding
2. 3/4" furring/airspace
3. ZIP 1.5" R-sheathing (R6.6 total, 12-16 perms for the OSB, <1.0 perm for the polyiso)
4. 2x6 studs
5. Icynene Low Density (5.5" thick R-20, 11 perms)
6. 1/2" gypsum

In GBA Pro help | Asked By Joseph Yount | May 12 15
2 Answers

ERV exhaust up a chimney

Can I run the main exhaust pipe of my ERV into the abandoned flue of my chimney?

In Mechanicals | Asked By Fred Richards | Jul 4 15
7 Answers

Log walls and foil facing

Hi,

We are planing to add 3 inches of rigid foam to the outside of our 6 inch log home, giving the walls R 28, better then the R9 we get with just the pine logs. We will also have a ¾ rain screen under cedar siding. I have been reading that if you had a polyethylene vapor barrier in the house, to not use foam with aluminum-foil facing.

In GBA Pro help | Asked By Thomas Gardner | Jul 3 15
15 Answers

Boiler upgrade recommendation?

I’m currently looking to upgrade my old boiler as it developed a small crack and is leaking. My current boiler is a P-468U-wt (151,000 btu/hr) Weil-McClain oil-fired boiler with a 40-gallon hot water holding tank.

I’m getting two different suggestions from two of my plumbers and would love some input on their recommendations. One recommends replacing it with an Energy Kinetics System 2000 and the other one is suggesting a Navien Combi-boiler.

In Mechanicals | Asked By Joe Pavia | Jul 1 15
6 Answers

Placement of vapor retarder for radiant heat in slab

I'm building a small house (~ 1000 sq. ft.) on a full foundation and am having radiant heat tubing installed in the slab. The plumbing contractor plans to staple the tubing to the foam insulation under the slab. I had planned to put the foam over crushed stone then a 10 mil sheeting over then the slab on that as I've seen in numerous foundation diagrams. But if the plastic sheeting is over the foam the staples for the radiant tubing will poke many holes in it so that seems like a bad idea.

In General questions | Asked By Martin Frank | Jul 3 15
6 Answers

Relative value of air sealing at exterior sheathing

I am trying to understand the relative value of air sealing at the sheathing. To do this lets consider cost as the benchmark. I realize that there is value beyond cost but this is an easily quantifiable benchmark and the one that seems most resonate with my clients.

In Energy efficiency and durability | Asked By Hugh Stearns | Jul 1 15
3 Answers

Nebraska — unvented attic with high humidity

Last year after a severe hailstorm the attic insulation and the entire roof deck of my 1600 sqft ranch style home in Fort Calhoun, NE was replaced. With the replacement we upgraded the insulation to Open Cell Icynene spray foam on roof decking. The spray foam is at least 6-8 inches on the roof, and covers the sidewalls, soffits, and attached garage ceiling. This completely closes in the attic to the thermal envelope of the house. I've been monitoring the relative humidity levels of the house for the last year.

In GBA Pro help | Asked By Nick Schuler | Jun 28 15
1 Answer

Spray closed-cell flat roof or not? Old brick walls - spray foam?

Greetings, Im currently renovating a 100 yr old rowhome end unit and adding a large framed addition that will have a flat roof deck surface that will be coated with FRP over OSB ;2x12 joists( no venting /warm roof) -there are so many controversial articles on how to properly insulate to avoid moisture entrapment it is dizzying..

In Green building techniques | Asked By Darron Zimmer | Jul 3 15
30 Answers

It's 2015 and they still build like this...

Brand new build going up in Phoenix, AZ. What you see is completely 100% framed and ready for stucco. The missing OSB sheathing is done on purpose. They do "open framing" and only use sheathing where required. The rest is open 2x4 framing.

They will stuff R-13 batts within the 2x4 walls, staple on some building paper and then put 1" of rigid EPS on the outside and use conventional stucco to finish it off.

A recent blower door test on a home like this showed 15 air changes per hour.

ALL of the duct work and air handlers are installed in the 150F unconditioned attic.

In Energy efficiency and durability | Asked By Peter L | Jul 1 15
12 Answers

Is my 5000 BTU LG 10 year old window unit significantly inefficient ?

My wife says so, in comparison with similar modern window units. She wants it replaced. The unit runs on all work days, during summer work hours, in my home office in San Antonio, Texas. San Antonio summers are hot, but not as hot as north Texas, as an example comparison. My question is whether efficiency advances in 10 years have made a big difference for small window units.

I tried to search, but every search returned hundreds of irrelevant topics.

In General questions | Asked By Weldon Cabaniss | Jun 28 15
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