Joist Reinforcement 2

[m63]

What would be the best way to reinforce existing 2x12@16 c/c roof joists for additional point loads since only way to double the joist would be to install second ply in two shorter lengths (installation of full length joist is space restricted)? Could it be still considered as a built-up beam when additional two shorter pieces nailed to existing;assuming splice piece provided at butt joint and avoiding max moment region for splice location?

 

[SlideRuleEra]

For your first question - If it does not matter what the bottom of the roof joists looks like, and the point load magnitude is not too great: at the point load location, install short (say about 36 inches long) 2 x 8 (for example) on the "flat", that are perpendicular to the 2 x 12. Lag bolt to the adjacent 2 x 12's to share some of the point load with the two adjacent joists. I also prefer to lagbolt or nail into the bottom of the heavily loaded member to tie everything together.

 

[KarlT]

How many of these joists would you need to reinforce? Do you know how much the existing joists would be overloaded? Are the point loads closer to the middle of the joist span, or near one end? Are the point loads a sustained load, or are they caused by snow/live/dead loads?

How you reinforce these joists depends on a lot of factors.