Masonry Bearing on Wood Bearing On Steel
Masonry Bearing on Wood Bearing On Steel
(OP)
I have a situation where open web wood floor truss bear on a steel beam. The architect is showing wood blocking between these floor trusses with masonry bearing on the wood blocking. What are your thoughts on this detail?
Should masonry bear on wood that is bearing on steel?
Thanks in advance.
Should masonry bear on wood that is bearing on steel?
Thanks in advance.






RE: Masonry Bearing on Wood Bearing On Steel
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Masonry Bearing on Wood Bearing On Steel
The 2003 IBC Section 2304.12 states that wood shall not support any dead load from masonry or concrete. But then gives four exceptions that can be done.
The 2009 IBC Section 2304.12 states that wood may support masonry or concrete if long term loading and deflection requirements are met.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Masonry Bearing on Wood Bearing On Steel
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Masonry Bearing on Wood Bearing On Steel
The reasons for not doing this, or the problems it can cause have not gone away as Mike implies, and I would try not to do it. But, the codes have become slightly more liberal about this detail if all the exceptions are met, and the inherent problems are considered, as Woodman suggests. Putting a few courses of decorative brick atop a good stiff wood structure is one thing; while putting a masonry bearing wall or a heavy non bearing wall on a flexible wood system is quite another. The Arch’s blocking should be well fitted and standing like studs, not on its side like a rim jst. or sill plate, because the latter will still crush and settle over time. Provide adequate bearing, compression perpendicular to the grain at all wood support points. Make the lower course of the wall a bond beam with some rebar in it, and use joint reinforcing in the lower courses, to make the wall act like a deep beam, thus preventing cracking, and spanning over any soft spots.
RE: Masonry Bearing on Wood Bearing On Steel
As per the OP detail, I do not see any way I would be willing to made it work (but I may approve of a detail that did work) and like msquared48 would place the masonry on the steel beam.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Masonry Bearing on Wood Bearing On Steel
Not my favorite detail - but you can make it work. Might want to use "treated" lumber.
RE: Masonry Bearing on Wood Bearing On Steel
So, bearing over wood, eventually you will see cracking in the masonry. Pay me now or pay me later...
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Masonry Bearing on Wood Bearing On Steel
It appears that this detail would only be used to support brick veneer approx 10' tall. So it is non-bearing however I'm still not sure that this is a good detail. I feel like 'soft-spots' could still be an issue and lead to cracking. I will think about an alternate detail.
EIT
www.HowToEngineer.com
RE: Masonry Bearing on Wood Bearing On Steel
I can’t see your detail from here, but that 10' high brick veneer would make me nervous too, primarily cracking with so many joints. Be sure your blocking is uniform and consistent to minimize soft spots or much flexing btwn. hard spots. Put a vert. stud type block along side each wood truss too, just for consistency, and then a couple btwn. each truss. At least you want uniform settlement. Maybe lag screw a 6x3.5 angle to the studs, and resting on the sill plate, or whatever, a shelf angle, acting as a tension member and spanning member. Don’t forget wind and water plane system, clean out of cavity, flashing and flashing drip edge, weeps, etc., all on top of the angle. Caulk the angle in btwn. the wood and the underside of the flashing. Make them install the brick ties as they lay the wall up, and plenty of them. Also, remember wood and concrete tend to shrink, while brick tends to grow in height.
RE: Masonry Bearing on Wood Bearing On Steel
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Masonry Bearing on Wood Bearing On Steel
If the masonry is exposed to weather, treated wood is required.
Another interesting note - brick exposed to weather 'grows'. Combining wood shrinkage with brick expansion can lead to ugly cracks if not carefully detailed.
LJ
RE: Masonry Bearing on Wood Bearing On Steel
RE: Masonry Bearing on Wood Bearing On Steel
EIT
www.HowToEngineer.com