[dave_dj1]

Hey guys and gals, I looked at a job the other day and it has me concerned.
Roof is very wavy and owner wants it fixed.
Log cabin was hand built in 87, roof rafters are flat one side logs, I believe they were put up green with no rime or reason as to placement.
Another "issue" is that the "builder" used 1x6 t&g over the rafters instead of 2x6 t&g then 2" of high R sheathing, then 5/8" wafer board (pretty sure it wasn't OSB, too long ago). Well here's the kicker, sheathing was put on with no regard to where it landed, just used 8' sheets and went with it, only nailing on rafters, ends float.
It has 3 tab shingles on it now.

Here is my plan of attack if I take it on:
remove shingles,
strap every 16" horizontally with 2x4's nailed and or screwed to rafters and shimmed to a string. Put 1 1/2" high R in between strapping/purlins, sheath vertically with 5/8" cdx, run new trim board to cover strapping and shingle with arcs.

This would all be over top of the existing wafer board sheathing and insulation.

Is the extra weight going to be an issue? The rafters are logs about 8" diameter, roof pitch is about an 8/12.
A) Should I call in an engineer?
B) Rip it all off to the rafters and use 2x6 t&g then 3" high R and sheath?
C) Run Forrest run!
Don't really want to run as I see it as a money maker but I don't need the headache.
Here's another option for the fix given that the rafters will support it all.
Put 2" high R over existing sheathing then strap horizontally over the rafters to level it all then strap vertically every 16" and sheath then shingle.

The owner would like the extra insulation, I think solid insulation as compared to in between the strapping would be better.

thanks,
dave

 

[Rio]

Depending on the span, type of timber used for the rafters, collar ties, etc. the weight might be an issue or not; if there's any question get a good engineer or competent archy on as part of the team. If you do get one that has practical experience, one who can work with you to come up with a solution that will work without breaking the bank.

 

[griz]

...

Is the extra weight going to be an issue? The rafters are logs about 8" diameter, roof pitch is about an 8/12.
A) Should I call in an engineer?
B) Rip it all off to the rafters and use 2x6 t&g then 3" high R and sheath?
C) Run Forrest run!
Don't really want to run as I see it as a money maker but I don't need the headache...thanks, dave

Perhaps have an Engineer look at it just to be certain you are not over spanned on the rafters & that the whole shooting match will work.

IMO, option B. Don't care for the idea of stacking chit on top of chit to hide something. Get to bare rafters & shim there when necessary to flush up you're decking.

Option C will likely be the best option. Disagree with your notion that this is a money maker. You are working on a DIY fuster cluck to start. Then you are up in the air & working on an 8/12.

Good Luck...:thumbsup:

 

[jaydee]

option #1 & #2
and or
#1 determine rafter load and span capability.

#2 strip down to 1 by sheathing , to verify condition

#3 strap with 2x6 horizontally, shim to string

#4 fill between strapping with high R foam board
4a strap w/ 3/4 vertically for venting
then
#5 use zip R sheathing

#6 replace trim board to cover

#7 roof as usual

this method doesn't allow for roof venting,
#4A allows for roof venting requirement

 

[roofermann]

I would emulate Gump.

 

[Kiwidan]

I'm no log cabin expert but.as my mother used to say when in doubt always get the appropriate people out to check things over... If that's not in the budget, as some others have said don't try covering other peoples cr*ppy work it always creates massive headaches just rip it off and start again