I am about to do some repairs to my roof rafters. A few of which have water damage to the ends.

My question is:-
a) When sistering a rafter, should I cut out the damaged part of the old rafter to stop the damage travelling anf further?

b) should I clamp both sides of the old rafter or is just one side sufficient?

Many thanks

Kemo

Just tag the new rafter back to the good part of the old. You really do npot need to cut it off but you do need to stop the water or whatever caused the damage to start with. I always use a power drill and long stainless screws when I do this. Do not be cheap with the screws use as many as you feel is necessary to help carry the load.

Note always take the new rafter back at least 5 foot or more to help spread the load from old to new. Much of this depends upon pitch of roof and weight.

Your Rafter May Be A 2x6 Which Ever It Is Use The Same Size, Buy You An 8ft Board And Cut It In Half, I Have To Disagree With The Screw Because Nails Have More Shear Strength Than Screw, Screws Hold Better In Different Situations. The Nails Id Recommend Are 16d Coated, This Would Be Up To Code, Good Luck , Nichols Trim

I just had what was supposed to be a tear down to the rafters but the roofer only ripped half of the roof and then added plywood over the existing roof making the roof heavier. I asked for it to be sistered from the wall out to the other end so that their would be one solid piece of wood instead of what looks like a 2x4 cut in pieces and going half way up th roof. Now that I know that the what I believe is called the dead load is not even supported how do I make the contractor fix it.
My code inspector is not even sure it will pass code with the extra weight.
I have a contract stating the roof would be torn completely down to the rafters.
Thanks,
Kathy

There is a difference between sistering and scabbing.

Sistering will be supported at the wall plate and ridge board. When sistering you can use either nails or screws 1 1/2'' from edge of rafter about one foot apart.

Scabbing will not run full length of rafter. When scabbing I would use either 1/4'' or 3/8'' bolts with fender washers. Would set them 1 1/2'' from edge and staggered 6'' apart. Scab should be at least 5 feet longer then the rotten section.

Chuck