sistering joists (thanks for the help!)

[qas]

I decided I will sister the joists that my plumber notched and drilled excessively. One question, the joist seem to be about 14 feet long, but I dont think I will be able to get a full length in because they are in between 2 walls. My idea is to put 12 or 13 foot joists up and then bolt the joist at each end so that they are tied to the existing joists. I will span them so that the bolts will be on the left and then right sides for each joist. Will this work? Will it strengthen my joists? I would appreciate any help.

Thanks for all the help guys!

[mrcaptainbob]

I did similar, had a 16 ft span, used 14 ft, managed to rest one end on a sillp late, jacked it in place, then through bolted every 18" in a staggered 'W' fashion. Rock solid!!

[qas]

I dont think I will be jacking it. My joists dont seem to sag. they are quite level. Is it still okay to do it without jacking them?

Will they still be strong?

[mrcaptainbob]

I would think so. The reason I jacked ours was to help take the strain from the 140 year old bow in them! I didn't fully staighten them, of coarse, but took off enough pressure so that the new ones, after nailing and through-bolting, would help accept the stress along with the old.

[HayZee518]

Actually jacking them with a removable lally column may be beneficial because if you view along the long edge you'll probably see "camber" or a slight bow in the planks. Another term is "cupping." Putting this "bow" downward then jacking it up flush and carriage bolting it together with the sister joist will help tremendously. [my opinion]