Fly Rafter Runing into Structural Roof Rafter
DoRight
| Posted in Construction Techniques on
If you have a fly rafter on a gable end which intersects a roof plain lower down, could you and or should you allow that fly rafter to become part of the actaul lower roof. I am guessing not as the fly rafter would penetrate the roof and create a possible water inflitration point. I suppose your flashing should make it ok, but just letting the fly rafter just run up and kiss the lower roof seems safer. Thoughts or best practices?
Replies
At least in Boise, and probably anywhere with snow loads of any kind, you'll need to run it into something solid - it doesn't need to penetrate the roof, but it needs solid wood under the sheathing where it intersects.
I don't think you understand my question, and I don't blame you as it is difficult to explain. Normally a fly rafter runs from the ridge down to NOTHING, it just ends at the eave. Right. You say it has to tie into something. No it is a fly rafter (unless I am using the wrong term and therefore really confusing things). Think of a typical gable end with a rack edge with a two foot overhang. There are two fly rafters, which of course have lookouts to support them. Now think about a building with an extention jetting out from this gable end half the width of the major gable with one wall in common with the minor extention gable. This minor gables roof plain would be in common with the major gable roof plain part way up the roof. As such one of the fly rafters from the major gable would intersect with the roof of the minor gable.
I wish I could post a picture.
You would stop the rafter from the higher peak - it would not penetrate the roof plane of the lower bumpout.
I have something similar. My garage is next to, and 9' forward of my main house. The front of the main house gable comes down toward the deck of the garage roof. I has to stop before it gets to the garage deck, otherwise water would flow down it into the garage.
I get what you're saying - but still, any framing rafters, ridges, etc. that rest on a the surface of a roof need to be supported under the roof with wood other than the sheathing - blocking between rafters - additional rafter - something. From the conversations with the inspector the thought is as things settle, and everything does, sheathing provides no resistance whatsoever and a depression can develop that could have been prevented with minimal support and the blocking provides something solid to nail to to keep things in place.
of course you have lookout and or blocking. Most fly rafters are supported by lookouts, run down from the ridge and CONTACT NOTHING. They end at an eave. I the case am describing the fly rafter on one side of the gable runs down and could intersect with a lower roof running in the exact same plain. The fly rafter could continue on INTo the lower roof where that portion of the rafter would be a structural element of the lower roof. The point is that the fly rafter would "penetrater the lower roof. It would then have to be flashed very well. Or you could just end the fly rafter short of the lower roof.
Sure wish I could post a picture.
The lower end of a fly rafter is supported.
By the sub fascia.
Do as Don suggests, run it down to the top of the sheeting (that's supported solidly underneath-rafter or blocking)
Flash it well and hold your subfascia up off the roofing. Don't forget to seal the end.
There is NO SUB FASCIA with open rafter tails! Therefore lookouts are your typical support with or without Sub fascia. Not really the issue.
IF you run the fly-rafter down to the lower roof but don't make it part of teh structure of the lower roof, why not hold it up off the roof by an inch or so. Are you saying why bother, jst flash it and also gain the added support of resting it on the lower roof?
Not to bet a dead horse as I am sure youcan do this any of a number of whys, but lets beat the horse, just to keep breaktime alive as it seems to be a dying forum.
Listen Do
you can do it anyway you please.
Just be advised that the joint where you propose is very much similar to the dormer fascia that dies into the roof and this is where countless times I've repaired rot and/or leaks.
Flash the structure properly. I might even add a strip of Ice and Water under that connection b/4 it is framed over. Run that up under any valley material you use.
I think at this point we need to start putting foraward drawings of what we are talking about!
paul
I'd put one fwd, but no scanner and no drawing program.
Yes. I still can't envision what the situation is he's concerned about.
It should be noted that it's not just the rafter, but the entire gable overhang that "dies" into the roof below.
Yes the sheathing dies into the roof and in the case I am attempt to discuss the sheathing of the over hang continues down, IN PLAIN) into the lower roof. Picture a triangle which is your gable then picture a smaller triangle inside the larger triangle with a bas half as wide as the larger triangle, but SHARING the same diagonal.
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Best drawing I can do.
Well, that pretty much is the opposite of what I thought.
So, what's the question? Do you connect the top where it intersects with the overhang of the larger gable?..................................................................................................................................................................................................................................................................
Pick one
He's talking about #3 -- DSC00010.
That is correct, #3.
Off topic, but is #2 a play house or something for adults? It's a cute design, but the scale of the trees is throwing me off so I can't tell how big it is.
edit: I'm wondering if it is for adults if there is an upper loft or just a high ceiling - I always enjoy this type of building. :)