Good afternoon all,

 We were called in to do an energy audit on a log home.  Very nice house but with ice build up and back up in winter and moisture on the interior main beam during summer.  We could see with infrared and visual inspection that there wasn't enough insulation but, with it being a log ceiling, we weren't sure how do address this.  We shared with the home owners that it looked like the roof had to be reconfigured to allow us to put in closed cell.  So, basically a new roof.  Has anyone ever encountered this before and what was the solution?

thank you!

Views: 251

Reply to This

Replies to This Discussion

Hmmm interesting that infrared can tell you exactly how much insulation... More like you have some thermal anomalies which show some issues which require more looking into. For typical issues like this you need to take existing roofing off & get down to T&G boards (assuming this style) / sheathing (if not other) & build it back properly carefully insulating the he11 out of it - recommend at least two layers offset & taped

Thank you, Sean.  Infrared did not tell exactly what we needed, only that our suspicions were correct.  We shot the house from the outside.  Anyway, we're still at taking off the roof, eh.

Yep especially if you got water issues as the insulation that was there is now essentially shot / water trapped & there maybe more issues you can't readily see (though infrared can help in that regard)

This is like those BPI "Stump the Chump" problems where there is not enough information to answer the problem, so the person with the best guess wins.
It is most helpful if posters noted the pertinent information. In this case, that would be things like, what kind of ceiling? (I am assuming cathedral?), what is the ceiling covering? (T&G? sheetrock?) what kind of roofing? (asphalt shingles?, shakes?, standing seam?) Is there a flat attic? Where is the house located (city/state)?

Almost all of the log homes that I have encountered around the Central Vermont area have standard 2x spruce rafters with fiberglass batts. One had a SIPS roof and another a "living roof" (sod and grass). Many of them have T&G ceilings which leak air.
As for infrared, I rarely look at a house from the exterior due to the many variables that could affect the IR. (I completed a Level I thermography class with Snell Infrared about 10 years ago, and I use IR a lot).
You need to know the structure of the roof in order to come up with a proper diagnosis and prescription.

"The more you look, the more you see", and "If you don't look, you don't see".

This is like those BPI "Stump the Chump" problems where there is not enough information to answer the problem, so the person with the best guess wins.

It is most helpful if posters noted the pertinent information. In this case, that would be things like, what kind of ceiling? (I am assuming cathedral?), what is the ceiling covering? (T&G? sheetrock?) what kind of roofing? (asphalt shingles?, shakes?, standing seam?) Is there a flat attic? Where is the house located (city/state)?

Almost all of the log homes that I have encountered around the Central Vermont area have standard 2x spruce rafters with fiberglass batts. One had a SIPS roof and another a "living roof" (sod and grass). Many of them have T&G ceilings which leak air. As for infrared, I rarely look at a house from the exterior due, especially roofs, due to the many variables that could affect the IR. (I completed a Level I thermography class with Snell Infrared about 10 years ago, and I use IR a lot). You need to know the structure of the roof in order to come up with a proper diagnosis and prescription.

"The more you look, the more you see", and "If you don't look, you don't see".

Thanks Brad.  You're correct on the missing info.  I do the customer service work and help do the actual audits but the boss does all the inspection work.  It is T&G and a cathedral ceiling.  I'm just trying to help the folks out and see if there are other options out there.  We're in western NY.

 I don't get how someone can sell a log home or a modular home in this area with the BS insulation they put in there.  At least tell the folks that it should be foam and FG batts and give them a price and let them decide.

Agree that its hard to help without more information. Pictures? IR images? Do IR images show air bypass or insulation voids? or both?

If its T&G with exposed beam rafters it would suggest the T&G is the roof sheathing as well as the finish ceiling and all existing insulation is outboard of that and is probably foam board. If that's the case, best to tackle from the outside and problems are likely due to foam board joints being leaky (perhaps broken seal from movement). If that's not possible, could talk owner into a new interior look and use the rafter cavity to do it right on the inside and then install new finished ceiling, T&G or other.

If its T&G continuous across the ceiling and no exposed beams there is probably dimensional 2x rafters behind it with crappy fiberglass/poly and its probably vented soffit to ridge (is it?) and leaky as all T&G is. In this case, could gut it or do it right from the T&G inward with air impermeable board insulation sealed to T&G, strapped and then install new finished ceiling.

I think either way you are looking at either a new ceiling or a new roof unless IR shows only air bypass and not voids and you want to just clear caulk a mile of T&G joints and hope for the best. I'd also double what was said earlier that you investigative if moisture issues are more severe than meets the eye before covering it all up with something new!

Best of luck!

I would look to stop air from penetrating the ceiling. I would guess hot air is able to rise through penetrations in the ceiling or the ceiling itself, washing batt insulation. If you are going to remove the roof and use closed cell foam it will fix the issue. closed cell pretty much fixes all problems. Another option is to use a clear coat polyurethane to seal the ceiling. Like finishing wood work.  Then caulk in all ceiling penetrations.

I built one of these two decades ago. From inside to outside....

Log main beams, 2 x 6 T&G ceiling, 6 mil poly sheeting, then 14 inch TJI spacer/rafter with R-38 batt and 2 inch air space, then roof deck with soffit and ridge vents.

We ran the TJI rafters out 3 feet past the side wall for summer passive solar shading on the windows, so we had the space to extend the fiberglass batts well outside the sidewall -- no cold top plate/top log.

We were wicked careful to keep the VB solid. The insulator shoving the batts in had a roll of tape on their wrist, with strict instructions to tape every flaw found.

In southern Wisconsin, this system worked. No icicles, no ice dams, even during the winter (2000-2001) that saw ice dams all over the southern half of the state. That's the winter I shot an ice dam photo that's STILL being used in a physics textbook.
Thank you everyone. Homeowners are removing the roof and we are going from there. I am going to speak with the log home company and go over some of the ideas offered here.
Bob

RSS

Forum Discussions

Mini split installation location

Started by Jan Green in HVAC. Last reply by Franco Oyuela 14 hours ago. 5 Replies

Think of the house as a really big duct

Started by Frank Spevak in HVAC. Last reply by John White yesterday. 2 Replies

Mini split air conditioners and ceiling fans

Started by Beverly Lerch in General Forum. Last reply by Beverly Lerch yesterday. 13 Replies

What's the Most Profitable HVAC Job for Your Company?

Started by Wayne Melancon in HVAC. Last reply by Franco Oyuela on Tuesday. 4 Replies

Latest Activity

Franco Oyuela commented on David Byrnes's video
Thumbnail

Why One Room Is Hotter Than Others

"If the temperature difference between your bedroom and your living room feels like walking from a…"
14 hours ago
Franco Oyuela replied to Jan Green's discussion Mini split installation location
"First: Mini split are a great option. Second:vI agree with David that installing on the south…"
14 hours ago
Pearl Home Certification's blog post was featured
22 hours ago
John White replied to Frank Spevak's discussion Think of the house as a really big duct
"Thanks for sharing this helpful information. Want to read more on duct cleaning pros and cons.…"
yesterday
Jan Green replied to Jan Green's discussion Mini split installation location
"Thank you, thank you!  I appreciate your insights.  I agree with the idea that installing…"
yesterday
David Butler replied to Jan Green's discussion Mini split installation location
"Hi Jan, in a room like that with a relatively balanced aspect ratio, flat ceiling and not much…"
yesterday
Rick Blair joined Kyle Brown's group
Thumbnail

Wrightsoft - Manual J / Manual D

If you use Wrightsoft to calculate loads or design ducts, you likely have questions.  Get answers…See More
yesterday
Jan Green replied to Jan Green's discussion Mini split installation location
"This is a very rough diagram of the detached casita.  There are currently no windows in this…"
yesterday
Sean Wiens liked Jerry Needham's discussion Condensation on ceiling and walls of master bedroom
yesterday
Andrea Simmonsen liked David Byrnes's video
yesterday
Beverly Lerch replied to Beverly Lerch's discussion Mini split air conditioners and ceiling fans
"Thanks.  A very reasonable, practical answer.  We have done our experimenting and ceiling…"
yesterday
Pearl Home Certification posted a blog post
yesterday
John Nicholas replied to Jerry Needham's discussion Condensation on ceiling and walls of master bedroom
"Jerry, ;Have you opened the cathedral ceiling?  "
yesterday
Blake Reid replied to Beverly Lerch's discussion Mini split air conditioners and ceiling fans
"Good opinions in these replies!  I'll just add a few: * Experiment.  It's your…"
Wednesday
John White replied to Jerry Needham's discussion Condensation on ceiling and walls of master bedroom
"Condensation on ceiling occurs when the attic space above is poorly ventilated or insulated. The…"
Wednesday
Joshua P Murphy is now a member of Home Energy Pros Forum
Tuesday
Franco Oyuela replied to Frank Spevak's discussion Think of the house as a really big duct
"THANKS for the information. Ducted mini splits offer hidden benefits."
Tuesday
Franco Oyuela replied to Wayne Melancon's discussion What's the Most Profitable HVAC Job for Your Company?
"Get into commercial, it's more money!"
Tuesday
David Byrnes's video was featured

Why One Room Is Hotter Than Others

Ever wonder if your air conditioner is working right because one room never gets a cool or warm as others? Do you need a bigger air conditioner to fix a room...
Tuesday
Profile IconEric MacCallum, Adam Morgan and Caolan Hutchens joined Home Energy Pros Forum
Monday

Photos

  • Add Photos
  • View All

© 2018   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service