Wall movement, inside corners seperating.

[tncastle]

I designed a single story wood structure, the inside corners of the exterior walls are separating at the top, but are tight at the bottom. The building as 80 feet wide so we went with a three piece truss design.
I'm just wondering if anyone else has run into this problem? Here's a little more info.
I?s built in Minnesota on frost footings with knee walls in the crawl space located to support the roof system. I don't have the soils report in front of me but the area it was built in is swampy. We designed it not to need interior walls for wind shear and because of an architectual design the carpenters didn't tie the top plates together. They retaped the inside corners after one seasonal cycle and the corners recracked.
The project managers are trying to pin the entire fix on the carpenters because the failure to tie the top plates together. My feeling is its just sesonal movement, any ideas? Thanks

 

[msquared48]

Sounds like the trusses might be deflecting to the point that the exterior walls are seeing lateral deflection at the top. ie, lateral kick.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[MiketheEngineer]

Agree w/M^2 - but could also be due to low and high humidity/heat cycles. Any steel beams or columns anywhere??

What kind of roof truss - anything like a scissors truss??

Top plates should have been nailed.

Might try caulking cracks with highly elastic caulk and then painting. I have had some success with that.

Floating corner beads are all the rage these days!!

 

[bylar]

if you did not tie the top plates together what is holding the connection?

 

[MrMark98335]

Your right, and the Project Manager is right. Failure to tie the top plate together is a contributing factor, and each winter the snow is going to cause the trusses (my guess scissors or vaulted) to deflect and push the top of the walls out. An 80ft span coupled with any kind of interior ceiling slope can lead to more than 3/4" horizontal deflection in the trusses. Did you use any slip clips (Simpson TC) at the truss to wall connections to allow for some movement without moving the top of the wall?