Minimum Bearing for Wood Floor Truss

[KootK]

I've got a client wanting to provide 2" of bearing for a 32' floor truss. We can probably swing some manner of voodoo to make the bearing values work but, in general, I'd like to have more bearing length. I worry that, once field tolerances rear their ugly heads, I'll be left with something like 1" of bearing.

Is there a code limitation some place that specifies the minimum bearing length allowed for a metal plate connected wood truss? I don't have a copy of ANSI/TPI I'm afraid.

Thanks,

KootK

 

[woodman88]

The wood truss design will show the minimum bearing width of the truss, per 2009 IBC section 2303.4. Field tolerances are an issue so your detail will have to be clear on what size bearing is required for the support. Cut detail on the plans at least twice as many time you would normally show it. Or maybe show the detail on the framing plan.

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.

 

[ztengguy]

Not to go off topic, I just dont get the reasoning we have to show twice as many details, or bold something, or underline something on our drawings.

Contractor "well he only shows that detail and dimensions once, so he must not really mean it. Oh wait, here it is again, he must be serious"

Our drawings are the way we communicate info to the contractor. If he cant read and follow directions, why is it our fault?, i know, we will get sued anyway. Otherwise, pay us to build it, or be on site to tell them what we have on our drawings.

Talk to the truss manufacture, and see what they say.

 

[woodman88]

ztengguy - Going off topic, when the contractor, truss manufacturer, Architect, Engineer and owner are all in a meeting about why the truss lengths on site will have a standard 3.5" bearing at the required location for a 2" bearing. The structural answer is "See we have the detail for a 2" bearing cut once on the framing plans right here!" I just do not like these types of meetings. If I have a special/abnormal condition I like to call attention to it.

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.

 

[KootK]

But does anyone know of a codified limit on truss bearing (independent of bearing calculation)? I'm looking for ammunition here.

 

[msquared48]

2006 IBC Section 2308.8.1 Bearing - 1.5" minimum

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[woodman88]

The 1.5" minimum bearing requirement (in the IRC/IBC codes) is only if there is not an engineered design for less.

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.