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FLY RAFTERS

FLY RAFTERS

FLY RAFTERS

(OP)
Residential structures often have gable ends with extended soffits.  Typically, a pre built fly rafter is attached directly to the gable end.  In some instances, when the gable overhang is too large, the gable must be dropped and the rafter extended back to the adjacent common truss.  My question is this... what is the max. length people typically use before dropping the gable top chord.  I realize this is dependent upon loading, etc., but was just wandering if there was a common rule of thumb that people are using for this.  Thanks.  

RE: FLY RAFTERS

I think it is more dependent on the span of the facia that the span of the fly rafter.  It is hard to argue you need those things on a dormer.  For real gables, I always speck them for stick framing or trusses too (and I mean the kind that cantilever over the gable end wall).  I think the only time you would never need them is if you don't have much of an overhang at all, like 2".  There is a lot of wind pressure on a gable end.

So I guess if you think you need fly rafters, you should drop the top chord because they really don't do too much just face nailed to the truss.

RE: FLY RAFTERS

I spec 5/8" plywood sheathing and in most instances you can can cantilever the plywood 12".  After that you can ladder fram under the overhang usually up to 16".
After that you need to drop the gable and frame to the fascia.  You need to chek the uplift on the interior framing at the inside of the outlooker member. Sometimes you have to drom back two spaces.

RE: FLY RAFTERS

Rule of thumb in Florida is anything over 12 inches. Connection of the rafter to the common truss and gable truss can be quite combersome requiring more than just toe-nails.

RE: FLY RAFTERS

Hi has anyone came accross a 4"x2" purlin in a dormer roof before. It is supported every 400mm with struts and the pitch of roof is 45d. Iam a little concerned, anyone got advise

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