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0 Answers

Retrofit of a Cathedral Ceiling

I am living in a Log Home in Madison WI. (Zone 5-6) with a vaulted Ceiling. (2x6 rafters R-19) I am hoping to redo the roof soon. I wanted to put on a layer or two of Rigid Foam. XPS or EPS. Ideally getting close to R-20 plus the 2x6 insulated cavity. I will then put a standing metal seam roof on top of the foam using furring strips.

My issues are this. I am concerned that I will be trapping moisture between the XPS or EPS and the Vapor retarder or Vapor Barrier that is most likely installed on the warm side of the house. Right behind the sheetrock and before the batt insulation.

Asked By user-6884681 | Jul 25 17
1 Answer

Sheathing Air Barrier and Vented Roof Assembly

Sheathing air barriers and vented roof assemblies both sound like wonderful ideas and seem to have the blessing of many building professionals. Are they compatible with each other?

I want to build a cathedral ceiling insulated with cellulose. Some people say such a roof must be vented and carefully detailed with an interior air barrier. Others are building them unvented with sheathing air barriers and are publishing their methods. Do you agree with them in any way?

Asked By user-6882359 | Jul 24 17
28 Answers

Cheapest way to build net zero house?

Hi. I have some questions about building an affordable net zero energy house. I will present a basic outline of my plan, and then ask some questions. In addition, I welcome any comments on any parts of the plan which could use adjustment.

Note: I am not a professional and only know what little I know from browsing these and other websites.

Asked By user-6877304 | Jun 28 17
8 Answers

My double stud wall assembly

We are in Minnesota (Zone 6a). 2200 sq/ft single level, slab on grade.

Finalizing my 10" double stud wall assembly details and want to get your suggestions and recommendations for improving the assembly without increasing significantly increasing costs.

-Certainteed Membrane 1-10 perm
-Dense pack cellulose
-1/2" plywood
-Tyvek 58 perm
-furring strips on the (north and east sides of the house)
-LP smartside lap, b&b, & shakes (north and east sides of the house)
-No furring strips, just vinyl siding (south and west sides of the house)

Asked By Scott K | Jul 22 17
1 Answer

Sand is becoming a scarce resource

Good Day,

There are a number of recent stories about the growing scarcity of sand and how this can impact construction, industrial and electronics industries (for example, see One example cited how China has used more sand for construction projects in the last few years than the US used on all of the 20th century.

Asked By Douglas Epperly | Jul 21 17
2 Answers

Build my own SIPs, or just frame it?

I am in the planning phase of building a second home and a shop on my property. I have access to as much insulation material as I need in 22" wide and various length (from 36" to 64") rigid foam insulation (door cut outs with the skins still on r 6.25 and 1 3/4" thick) for free!

Asked By Mathew Bean | Jul 20 17
3 Answers

Can I use two layers of Tyvek in a wall assembly without moisture problems?

I am building a house which has a REMOTE wall system in it (foam "outsulation"). Although I passed on the relevant information to the builder, who is usually on top of the details, he managed to mess up with the window bucks.

The wall structure is 2x4 studs (with R13 cavity insulation), plywood sheathing, Tyvek Drain Wrap (wrinkled stuff) 2 layers of EPS foam of R10 each sealed with Siga Wigluv tape, then 3/4" plywood furring strips followed by wood siding.

Asked By Gary Dick | Jan 11 15
3 Answers

1926 Tudor basement finishing project


Our house is a 1926 Tudor located in Minneapolis. I am in the process of finishing the basement. Planned insulation is 2" rigid (polyiso or XPS) with 2x4 stud wall. I am only air sealing the rim joist due to the fact my floor joist are half buried in concrete.

Asked By Joe Sweeney | Jul 18 17
24 Answers

Rainscreens with Roxul Comfortboard IS?

Hi all.
I am planning out my wall construction for a home in zone 6. Not much rain (15" annually), but plenty of snow in winter (56" annually). Hot (and mostly dry) in summer (80sF to low 100s), cold in winter (mostly lows in the single digits, but sometimes minus teens F). My house will not have much direct sun due to northern exposure and tree shading.

All that said, here is the wall I am considering:
- wall board
- 2x6 fir studs on 16" centers, Roxul Comfortbatt (R23) between the studs
- OSB, taped and sealed for my air barrier
- house wrap for vapor barrier

Asked By Mike B | Mar 20 16
5 Answers

Confused about continuous insulation in Climate Zone 5

I'm planning a home in zone 5 (northern Utah). I'm so confused by all the differing opinions on how the wall assembly and different barriers should be installed. And I'm definitely not getting much help from my general, or his insulation or exterior subs. He's definitely for trying out exterior insulation, and understanding the thermal break it can create, but he doesn't even know his EPS from his XPS from his PolyIso. The insulation guy was somewhat helpful, but his expertise mainly lies with inside-the-wall insulation.

Asked By ccutrer | Jul 13 17
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