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2 Answers

Passivhaus House - NC mountain home

Would someone provide some guidance on building to a Passivhaus design - especially with the wall stud design / insulation material. From what I read - we need to plan of R50 or R60. The most efficent design would be for foam but I would like input on wool.

Thank you.

In Energy efficiency and durability | Asked By bill Moseley | May 31 15
9 Answers

How to air seal from interior with pine siding?

We just gutted the interior of our ~1950 cape on Long Island (NY). The Bottom layer of siding appears to be Pine 1x in good shape with cedar shingles on top of that. I want to air seal the siding from the interior, what's the best way to do this? I assume caulk, but which type? or could I caulk strips of tyvek into the bays?

Question #2:

In Green building techniques | Asked By christian routh | May 29 15
5 Answers

Minisplit in tandem with a conventional heat pump?

A friend is getting ready to build a 2800 sq-ft retirement home in the hot and humid south, (Houston). His HVAC contractor is recommending a 5 ton, two stage heat pump. This is ~ the traditional 1 ton / 500 ft2 formula that prevails in this area with the added benefit of the two stage compressor. But 5 tons seems like a lot for a tight house and 2.5 tons is hardly the optimal dehumidifier in the light HVAC seasons. The house will be insulated with closed cell foam in the walls and under the roof deck. It is not what you would call an open floor plan.

In Mechanicals | Asked By Dean Wiley | May 27 15
11 Answers

Skylights that sit flush but don't leak! Do these exist?

I am trying to daylight a currently unused attic under a shingle roof. Because we're in a historic district, we're not allowed to visibly alter the roof's silhouette (so no dormers or protruding skylights). My architect has proposed switching to a standing seam metal roof with thin glass skylights slotting into the metal seams (as seen in the attached pic). I'm worried that the lack of flashing will lead to leaks. Does anyone have experience with skylights that sit flush but don't leak? Or am I chasing a unicorn?

Your feedback much appreciated!

In General questions | Asked By Nathalie Jordi | May 27 15
6 Answers

Basement slab perimeter insulation

I was told that the updated code for Zone 5 required R-10 Foam for 2' around the perimeter of my basement. Local code has not updated to the modern one that states this, but I would like to do this anyway. My question is...does this mean 2' of foam going vertical against the footing, or 2' of foam horizontal butted up against the footing that goes around the inside perimeter of the basement? I am trying to understand what the benefit of just 2' does?


In General questions | Asked By Nicholas C | May 28 15
6 Answers

Recommendation for unvented cathedral ceiling retrofit from outside

I have a 1980's cathedral ceiling section (2x12 raftered) of my home with soft sheathing problems. Hence, I need to remove the sheathing and re-roof. Most recommendation are to spray foam against the sheathing, but this requires an additional interior drywall removal and the interior mess and disturbance I'd prefer to avoid. There are also recommendations for large 6+ inch of rigid foam to the outside of the sheathing, this causes difficulty with the home appearance at the eave and problems with adjacent roof lines that aren't cathedral.

In Green building techniques | Asked By David koeberlein | May 28 15
2 Answers

Overinsulating or underinsulating?

We have a home built in 1986 in Columbus, Ohio (Zone 5). We are replacing our siding due to hail damage and plan to have the following layers on our home:

1. drywall
2. 2x4 walls with unfaced batt fiberglass insulation (R?)
3. polyiso 1/2"? - (old, some gaps, foil faced, says "R3.6" on the face)

4. 3/8" EPS w double foil face (~R1.5) - http://www.thermalbuildingconcepts.com/technical/propertySheet/ps-Physic...
5. Tyvek
6. Cedarmax insulated vinyl siding (R2.4) - http://www.proviaproducts.com/productdetail/vinyl-siding/cedarmax/

In Energy efficiency and durability | Asked By Chad B | May 27 15
3 Answers

Confused — We are in the process of remodeling a home in upper N.H.

We have used Zip R on the exterior sheeting, Zip board on the roof sheeting and foamed the interior to R-27 wall and R-38 roof. We were ready to install radiant floor heat using warm board.

I am thinking mini split for the 2nd floor bedroom and return hot water for the main floor and basement.

In Mechanicals | Asked By Joseph Maraldo | May 28 15
17 Answers

Unvented roof underlayment and rafter bay insulation

Hi guys...first time poster, love the site its been a huge help. I've just finished framing my home in Montana and am ready to move on to the roof. It consists of multiple single pitch decks ranging from 1.5" - 2" in 12. Framing is 2x12 rafters.

In Energy efficiency and durability | Asked By Stan Smith | May 27 15
4 Answers

Rainscreen venting connected to cold roof/back vented channel

Thoughts on connecting the vertical rainscreen vent channel to the cold roof/back venting channel on the roof or separating them.

I saw this last winter where the two channels are connected:
The solar washing of the siding caused subsequent ice damming even on a cold roof, due to the warmer air that comes from behind the siding was escaping up, under and out the roof peak. Anyone else encounter this?

Have you seen details that could eliminate this, but still provide an easy pathway for the vented air to escape?

In General questions | Asked By Brad Hardie | May 28 15
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