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7 Answers

Detailing flashing, waterproofing, and the various layers of exterior roof insulation and at the valleys and sidewalls

I am playing with how to integrate the different layers of thick exterior insulation, flashing and WRB at the top of the window/door trim, at the roof/sidewall, and at the valleys when using the PERSIST or ETMMS type methodologies. The window and door details are obvious when it comes to flashing right to the window or door flanges, but the other details are a bit more complex.

For instance:

Asked By brad hardie | May 28 15
4 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!
Nathalie

Asked By Nathalie Jordi | May 27 15
3 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?

Asked By Brad Hardie | May 28 15
16 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.

Asked By Adeeb Hattar | May 27 15
1 Answer

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:

Existing:
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)

New:
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/

Asked By Chad B | May 27 15
1 Answer

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.

Asked By Dean Wiley | May 27 15
5 Answers

Attached garage with steps leading into basement

We are building in SE Wisconsin. Currently just figuring out floor plan, in a rough design stage. Main level of house approx 1 ft above grade to approx 4 ft above grade on south side. Basement of house to be partially finished on south 1/2 of house. Attached garage on north side of house. Garage to be on same level as main floor of house. My questions deal with having a stairway in the garage leading to the basement level.

Asked By Dirk Denzin | May 26 15
5 Answers

Perlite in wall cavity recommendations.

I have a 2x4 wall cavity that is only about 5" wide. The cavity contains a steam pipe which is uninsulated. The cavity is obscured by another wall that makes access to it very difficult.

I would like to fill the cavity with perlite to insulate the steam pipe. I can close up the wall to prevent the perlite from leaking out, and have access to the top.

The house was built in 1928. From the outside: brick, air gap, roofing felt, 3/4" tongue and groove.

Asked By Kurt Kiley | May 25 15
1 Answer

Is cellulose fiber insulation treated for mold/water infiltration?

how durable is cellulose fiber insulation on a typical say 3 bedroom family house, will it typically last 20 years under normal usage conditions.

Asked By Alice Onaga | May 27 15
3 Answers

Add exterior foam -- but (woops) poly sheeting?

This is a follow up to my question from yesterday - "Add exterior foam -- but paper-faced batts?"

Well, at the advice of my builder I cut some test holes and darn.. poly sheeting over the batts, not kraft paper as I thought.

So the same question applies - what are my options, if any, for adding exterior insulation during this window replacement project?

Thanks again.

Kyle

Asked By Kyle Hollasch | May 27 15
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