Wood framed partition walls same height as bearing walls? 1

[jeffhed]

I want to find out what occurs in other areas of the country on wood framed partition walls. Here all bearing and partition walls are framed at the same height. This ends up leading to drywall cracking in multiple story structures where partition walls are located in the midspan of a truss. The truss can't deflect, and ends up "bearing" on the partition wall. This causes the floor joists or sheathing to support loads that were not originally intended. The floor joists then deflect more than intended causing drywall cracking in the ceiling on the lower floor. I have done a lot of distress inspections recently where this has been one of the causes for ceiling cracking. We specify that the partition walls be framed a fraction of an inch lower than the bearing walls to make sure the trusses have room to deflect without transferring load to the partition walls. However, I am positive this is never done in the field. I want to get some input as to what others do to preserve the intended load path.

 

[spats]

Turning every wall into a bearing is totally impractical for most applications.

 

[a2mfk]

Only two ways I know to prevent that type of cracking- fix the joint so it is rigid and little to no movement is allowed, or install an expansion joint. Even with the former the rotation movement may be enough to cause hairline separation of the gyp compound along that joint. The latter is not standard practice but could be one day At my house I would use crown molding or a caulked joint to accommodate this movement.

Stucco and other cementitious compounds and gypsum joint compound make very poor crack and joint filler materials due to their lack of elasticity, I see their failures every week... Something to keep in mind.

 

[jeffhed]

spats,
I am not turning every wall into a bearing wall, just this one partition wall on this one unit.

a2mfk,
I have told pretty much the same thing to the contractor as far as how susceptible those materials are to cracks. He wanted to know a few options so he doesn't have drywall cracks in the same location on the newer units.

 

[spats]

See the attached document I found online. It explains the situation.