I'm looking for suggestions about how to upgrade a vented cathedral ceiling covered with very nicely finished (albeit leaky) tongue and groove pine. Some specifics:


About 1/2 the assembly is vented from eave to ridge. The other 1/2 is tied into an accessible attic flat. Presumably, the 14" TJI's have poorly installed styrofoam proper vents. I don't believe they go all the way to the ridge and are not air sealed at all.


The 14" TJI is insulated with faced FGB (12"). The facing is installed to the warm side of the home.


There is a metal roof and the customer has no intention (or budget) to remove it and install rigid on the roof.


The tongue and groove is finished nicely with several coats of clear coat. It's a high end home and this assembly needs to be put back together perfectly.


The ceiling is peppered with recessed lights.


Each slope is 14' long and the room is 26' long.


I've noodled around with a few options based on the customer's budget and what we're hoping to achieve. They run the gamut from removing the T&G and FGB, installing sheetrock as an air barrier, dense packing the cavity, and re-installing the T&G. The ridge and eaves would be blocked and we'd have a hot roof. Moisture load in the home in low and managed.


Another option was to access the eave and ridge and 2 other area but removing strips of T&G. We'd then remove the FGB, block eaves and ridge, install 1" of CCF on the back side of the T&G (as an air barrier) and dense pack the cavity with cell. Might trap moisture, though?


How about removing sections of the T&G, removing FGB, and adding 3" of CCF to the underside of the roof then dense packing and re-installing T&G? Not a perfect air barrier but the likelihood of condensation is reduced from the foam.


Straight up dense pack the assembly? Just block the soffits/ ridge and keep the FGB?


I think creating a hot roof makes sense as it would be challenging to install a continuous vent from eave to ridge.


Like all T&G, the corners are leakiest although in this assembly, it was all leaky during my BD test.
Tongue and groove cathedrals without a proper air barrier (and poorly/ incorrectly vented) are a bugger! If anyone has any ideas on a reasonable way to make this assembly perform better, I'm open to suggestions.
Thanks!
Matt

Views: 2191

Replies to This Discussion

Funny! Most people ask me how Ben Affleck is but you're a little more creative and topical.

RSS

Discussion Forum

Moisture/Mold on rim joist;

Started by John Shillito. Last reply by John Nicholas Jan 10. 6 Replies

Radon - Passive Systems

Started by Sean Lintow Sr. Last reply by Bryan Gabriel Jan 5. 5 Replies

Vented Soffit! DO or DON'T?

Started by Daniel Baur-McGuire. Last reply by Daniel Baur-McGuire Nov 15, 2016. 13 Replies

Water Saver or Gimmick?

Started by Sean Lintow Sr. Last reply by Bob Blanchette Oct 23, 2016. 18 Replies

Duct Testing - is a change in order?

Started by Sean Lintow Sr. Last reply by Sean Lintow Sr Aug 6, 2015. 20 Replies

Videos

  • Add Videos
  • View All

Latest Activity

Chris Woods added a discussion to the group Energy Auditing Equipment for Sale, Trade or to Purchase
Thumbnail

Minneapolis Blower Door Fan and Door frame $990 OBO

I have a used Minneapolis blower door fan (fan only, no controls or panel) and the blower door…See More
yesterday
Profile IconManuela L Heyn and Paul Nagel joined Home Energy Pros
yesterday
Bill Spohn replied to Eric Sperline's discussion Wanted: Energy Auditing Equipment for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"If you choose to buy new, give TruTech at call at 1-888-224-3437 option 1"
yesterday
Home Energy Magazine's blog post was featured

The Legends of Home Performance

A project long in the making, we're happy to finally reveal some of our Legends of Home Performance…See More
yesterday
Quinn Korzeniecki replied to Larry R Waters's discussion BPI Anaylist
"Hi Larry, We're glad you're reaching out to hire some BPI folks! You can also submit…"
yesterday
Larry R Waters posted a discussion

BPI Anaylist

Industry leader in the north bay area California. Looking for experienced professionals and future…See More
yesterday
Larry R Waters joined Diane Chojnowski's group
Thumbnail

Job Board

This group is for posting jobs related to all aspects of the home performance industry including…See More
yesterday
John Nicholas replied to Jim Fowler's discussion TREAT modeling of mid-rise apartments low heating load
"So why is tenant behavior significantly different in this building?"
yesterday

Home Energy Pros

Welcome to Home Energy Pros – the unique digital community by and for those who work in the home energy performance arena.

Home Energy Pros was founded by the developers of Home Energy Saver Pro (supported by the U.S. Department of Energy) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network. Please honor our Guidelines

© 2017   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service