Hi guys…
Snapped valley rafter – repaired and bolstered, but the ridge line still sits about 4″ below where it should be.
The homeowner wants us to fill in or build up the area that has settled … basically, to try and level out the swale so that the roof at least appears to be flat.
My thought is to lay furring strips 2′ o.c. and lay some sheathing overtop, set to string lines.
I know I havn’t explained this very well, but I hope you can get the gistof it.
Anyone done something like this before?
Thanks guys!
Replies
Me thinks the issue of the settling should be addressed first.
Obviously I'm not lookin' at what yer lookin' at but my first instinct is that I'd go up in the attic with a jack and some cribbing and push the ridge back up. I don't see how the valley rafter can be repaired if it's shorter than it was before, or not straight, or both. If it's been repaired in the lower position then there are a lot of new forces being absorbed elsewhere in the roof that probably aren't appreciated and may lead to future problems.
What caused the valley rafter to break? Design error? Termites? I had one valley rafter nearly gone from termites, with very little deflection. In my case, adding vertical 2x4's from bearing walls to the ridge helped a lot in getting the ridge straight.
It's real hard to say much about this without seeing it. Can you post pictures?
-- J.S.
You've given two symptoms of this sick roof structure. They point to something wrong and you are asking how to cover it up basically. Better to find out why the valey rafter broke and the ridge sags.
I'm betting the whole thing was understructured in the first place and the only thing you would accomplish by adding shim weight is increasing the overload and creating more problems.
Analyse the entire structure before you start to do anything, otherwise, whatever goes wrong once you touch it could be your fault, at least in the eyes of the owners
Excellence is its own reward!
Hi All. (warning - this is a long winded explanation)
Sorry for the lack of info...
Snapped valley rafter at approximately 10" - 12" above an intersecting ridge. The valley rafter continues past the intersecting ridge approximately 2 feet to the main ridge. Picture a long main structure with a perpendicular structure meeting it. Basically a T when viewed from a floor plan.
As for the reasons for the break? The 2 x 12 valley rafter is approximately 20 years old - there are several knots directly below the break, and a large (1" -1 1 1/2") hole had been drilled for a lightning rod cable.
It is a combination of the load, the knots and the cable hole which led to the break by weakening the entire area. However, it is my belief that another major factor in the break was excessive loads placed on the area due to settling of log walls, and the lack of settling allowance on other walls. By this, I mean that the front gable wall settled significantly while two support walls on either side of the intersecting ridge were not allowed to settle.
At any rate - this entire area is a great room with no attic space and the snapped area is approximately 20 feet above the main floor. We removed the T&G ceiling and jacked up the split valley rafter. We then used a 1/4" x 8' x 10" steel plate on one side, with 11" x 11" plates on the back side between the jack rafters. We drilled the main plate and the back plates and sandwiched the entire area - much like a truss.
However - due to the long term problem with the roof, even though we had the valley rafter jacked up to it's proper height - the rest of the effected area is still low.
Obviously, the best way would be to provide interior beam supports in a couple of areas - however, the homeowner does not want to have any beams or posts in the great room.
So what we're left with is a dished area surrounding the intersecting ridge. The most noticeable "humps" are where there framed walls on either side (parallel) with the intersecting ridge.
whew... At some point I'd like to posts some CAD drawings to see how everyone else would have handled the problem.
In retrospect - the proper approach would have been to hire in an engineer and let him tell us that the whole roof would have to be rebuilt.
As an update - since the entire roof is kind of wavy anyway,I've decided to just shingle over the dished area and see how it looks.
Edited 12/9/2003 8:15:10 PM ET by petmonkey
"excessive loads placed on the area due to settling of log walls, and the lack of settling allowance on other walls. By this, I mean that the front gable wall settled significantly while two support walls on either side of the intersecting ridge were not allowewd to settle."
Curious to know what is meant by "settling" and "settling allowance". The soil or the structure or both? I'm not familiar with log building at all, but am recently living in an area with a lot of log houses (almost bought one, in fact).
Thanks!
Hello David... when I refer to "settling," I'm talking about the settling of a log structure as the logs lose moisture and shrink.
In log structures that use green, large logs - you can expect to see a house settle up to 6" as it dries. Basically - as the logs get smaller, the whole house settles down to the foundation or subfloor.
The house I'm discussing this time - used 6" 2-sides sawn logs. Each of these logs would typically lose from 1/8" - 1/4" in diameter as it dries. Assuming 17 - 20 courses of logs, that's between 2 and 5 inches.
The problem occurs when settling allowances are not built into the structure - for instance, around windows and doors, and underneath support posts,which will not shrink significantly.
Imagine a framed wall on the interior of a log structure that meets the floor joists of the second floor. As the entire perimeter of the house settles with the drying logs, that framed wall will eventually take a tremendous amount of load from the entire structure because dimensional lumber does not shrink or settle with the logs.
Hope this answered your question.
Edited 12/9/2003 8:16:40 PM ET by petmonkey
Very clear explanation, thank you.
This Valley that your talking about is called the "Supporting Valley" which runs all the way to the main ridge and then there's a smaller valley nailed into it which is called the "Supported Valley".
A Supporting Valley doesn't need any beams or posts in a Cathedral ceiling situation. The Valley should be properly sized so you don't need to put posts under it. We frame them all the time with double LVL's or one time years ago we used 2-1-3/4" x 11-7/8" LVL's with a 1/2" flitch plate sandwiched in between them for a Cathedral room like your room but this was all calculated by an Engineer.
Your Supporting Valley BROKE and now your saying that We then used a 1/4" x 8' x 10" steel plate on one side, with 11" x 11" plates on the back side between the jack rafters. We drilled the main plate and the back plates and sandwiched the entire area - much like a truss.
So now you drilled more holes in the Supporting Valley where it snapped. This should've been looked at by an Engineer. What makes you think that that's the fix. I'm not trying to be smart with you but this shouldn't have been anyone elses call but an Engineer.
I personally think that the valley jacks on the opposite side of the Supported Valley should've been propped up and cut back and add LVL's or a Flitch plate the full length of the Supporting Valley from the outside of the wall plate all the way to the main ridge and maybe even adding an LVL on the other side from the Intersecting Ridge up to the Main Ridge.
A Framer can tell you what they have used in their experiences from Framing new work and tying into old roof framing and what size beams we've used in many situations because we don't to the calculations the Architect or Engineer has them specked out for us.
Your situations is alot more involved and I wouldn't feel at all comfortable with what you did or I wouldn't feel comfortable in using my own ideas without talking to an Architect or Engineer, so no one can really tell you what the right thing to do is unless they're an Architect or Engineer or seen your project that knows every measurement and the pitch of the roof.
I hope it works out for you.
Joe Carola
Edited 12/10/2003 6:26:14 AM ET by Framer