Helpful? 0

Zone 3/Central GA 12x32 weekend cabin on 36" above grade piers

Building Envelope Critique Please/Materials purchased and we're about to begin:
1) From interior: 1x6 T&G pine fastened directly to 2x6 studs 24" OC; R-19 fiberglass batts/caulked gaps & seams; 1/2" plywood sheathing; one layer 1/2" pink foam board/taped seams; 4x8 exterior panels. Where is best positioning for my WeatherMate Plus wrap?
2) Floor system: 2x10 joists; R-19 batts; two layers of 1/2" plywood; interior flooring to be reclaimed heart pine planed to 3/4" glued and cut-nailed to plywood. Considering Building Science article approach to apply 1/2" pink foam board to underside of joists/tape seams. May WeatherMate Plus wrap be incorporated and between what layer(s)?
3) Roofing from interior: Same T&G as on walls directly to 2x6 rafters 24" OC; R-19 batts/caulk & sealing; 1/2" plywood; 2 layers of 1/2" foam board/taped seams (overkill in zone 3?); purlins and 5V galvanized metal roof. I have excess of WeatherMate Plus wrap - may it be utilized in the roofing plan in lieu of #30 felt? 4 x 12 pitch gable with no penetrations in the roof deck.
The cabin will have a small bathroom with shower/sink/through wall exhaust fan. No cooking will take place indoors.
Please provide ALL pro and con comments and suggestions. This is a fantastic site, along with Building Science and Fine Homebuilding Magazine!. Thanks in advance.

Asked by Brad Skeeters
Posted Fri, 03/14/2014 - 08:31

Tags:

3 Answers

Select your preferred way to display the comments and click "Save settings" to activate your changes.
1.
Helpful? 0

Brad,
Q. "Building envelope critique, please."

A. Your walls and ceiling need an interior-side air barrier. Tongue-and-groove boards are notoriously leaky. The best approach is to install a layer of drywall with taped seams before you install your tongue-and-groove boards.

For better floor insulation details, see How to Insulate a Cold Floor.

For better roof insulation details, see How to Build an Insulated Cathedral Ceiling.

Q. "Where is best positioning for my WeatherMate Plus wrap?"

A. See this article: Where Does the Housewrap Go?

Answered by Martin Holladay, GBA Advisor
Posted Fri, 03/14/2014 - 09:11

2.
Helpful? 0

Martin: Thank you - a follow-up: Assuming I have 'extra' 1/2" plywood, will that serve the same purpose as the taped-seam drywall approach?

Answered by Brad Skeeters
Posted Mon, 03/17/2014 - 12:29

3.
Helpful? 0

Brad,
Q. "Assuming I have 'extra' 1/2" plywood, will that serve the same purpose as the taped-seam drywall approach?"

A. Yes, but only if you tape the seams of the plywood with a high quality tape that is suitable for use on plywood. For more information on tapes, see Return to the Backyard Tape Test.

Answered by Martin Holladay, GBA Advisor
Posted Mon, 03/17/2014 - 12:43

Other Questions in Energy efficiency and durability

In Green products and materials | Asked by John Alberti | Aug 26, 14
In General questions | Asked by Sam smith | Aug 26, 14
In General questions | Asked by andrew c | Aug 27, 14
In General questions | Asked by Mike Collignon | Jul 24, 12
In Plans Review | Asked by Nick Campbell | Aug 26, 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!