Joist Bearing Surface

[ttmon12]

I had to replace the joists supporting a second story bathroom in my 1930's brick rowhouse. The original joists (actual 2 x 10s) sat on the inner course of bricks with slate shims. Is there a stardard for the minimun bearing surface (how far the joists over lap the bricks) for this construction method? 1", 2", 3"??. The longest I was able to cut the joists and still angle them into the wall left 1.5" of joist over the brick. Any thought are appreciated.

[awesomedell]

As long as the masonry work is solid at the edge, 1-1/2" overlap onto the brick will be sufficient for support.

[A_unique_name]

you must figure the reaction of the joist. Then divide the reaction by the bearing area to obtain the load per PSI. AFter you have that number then you can determine if BOTH the joist and the bearing are adequate. Anything less is simply someone's guess!

[ttmon12]

Thanks for the replies. All the codes I found called for 3" over brick and 1.5" over metal or wood. I ended up with 2" - 2.5" of bearing surface (the 1.5" earlier was a conservative estimate) and feel comfortable with that. Made up some steel shims to level the joists and set them in mortar.