Bearing Perp to Grain 1

[miketrags]

I'm curious to get some other opinions on exceeding compression bearing perpendicular to the grain stresses on bottom stud wall plates. It seems to be more of a serviceability issue than strength issue. Does anyone else neglect this limit in some cases?

Curious for thoughts/opinions on this matter.

 

[COEngineeer]

I never neglect it. Dont forget you have Cb factor that can increase your perpendicular stress capacity a little bit. Dont forget sometime you use a different species of wood (i.e. treated hemfir). Are you talking about stud pack? Just add another so you dont crush the plate.

Never, but never question engineer's judgement

 

[miketrags]

This is a 3 story wood building and I have typical bottom plates on my bearing walls that aren't working. My detail has 2 bottom plates above sheathing, above a rim joist running parallel with the wall and floor joists perpendicular to the wall. I could add a 2nd rim joist but on the firts floor that still doesn't help. I'm already using souther pine no. 2 which has 565 psi with a 1.5 Cb factor.

Maybe having 2 bottom plates help spread the load?

 

[msquared48]

Never, Never, Never.

It leads to crushing of the plates and finishing damage issues, particularly in sheetrock. Not a good condition in condominiums... Lawyers love us to do that though! It pays their bills.

I use either more studs or, as a last resort, steel bearing plates, so as not to exceed the valus.

Mike McCann
MMC Engineering

 

[COEngineeer]

double bottom plates will not do anything. It will still crush it. Are you using 2x6 studs @ 16" o.c.? The perpendicular bearing is not good enough? Maybe you should use an engineered wood product for the bottom plates. That will solve it.

Never, but never question engineer's judgement

 

[hokie66]

Agree with others. You need to use a different material for the plate or spread the load.

 

[RVSWA]

Tighten up your stud spacing or even use 3x studs, I know some liberal engineers who don't flirt with plate crushing.