If a house suffers from truss uplift the top floor ceilings literally lift off the interior walls in the winter.
How to repair bend in roof truss uplift.
Because the bottom member of the truss is usually buried in insulation and the upper members are cold that the expansion of the bottom member is greater than that of the upper members the resultant is that the bottom member of the truss bows upward.
They drop back down in the summer.
Truss uplift usually occurs when the truss is exposed to a change in moisture and or temperature conditions causing the truss to arch up in the center.
Arching roof truss uplift drywall cracks at the ceiling wall joint.
This article series explains why arching trusses happen where the damage will appear how to recognize it how to truss uplift cracks from recurring and how best to repair cracks due to rising or arching roof trusses.
There are numerous suppositions on why this occurs.
The most accepted of the suppositions is.
Truss uplift is not truss uplift if the homeowner can t see it.
Bob schmidt shows you how to handle a common problem that can occur when you have a truss style roof in your home.
Here we provide a definition of arching roof truss damage or roof truss uplift and we explain why truss uplift occurs where truss uplift cracks will appear and how roof truss uplift cracking can be avoided or corrected.
If you happen to be building a house now borrow a step ladder and inspect the trusses which pass over interior walls.
Repair roof truss uplift problems before the start.
If the truss can move and the can drywall bend no crack will result and the homeowner will be happy.
Expansion and contraction of roof trusses causing truss lift in winter.
Q a about rising or arching roof truss uplift drywall cracks at the ceiling wall joint.
If not and you need to repair existing truss uplift problems complete your repair in two phases during winter and summer by using proper l brackets drywall clips and retention blocks.
I think the best approach is to stop the truss uplift from having an effect on the drywall joints let the trusses move.
When a house shows signs of interior ceiling corner cracking at the top of the wall it is commonly due to truss uplift.
And that allows the truss to move up and down and it will relieve some of that uplift and cracking.
Roof battens 4 roof framing and trusses 4 figure 1 roof uplift load width ulw for wind 5 table 1 uplift forces on roof battens 6 detail sheet 1 roof battens to rafters or trusses 7 detail sheet 2 rafters to rafters at ridge rafter to underpurlins and to ceiling wall frame 9.
Figure 3 roof truss in uplift position.
The clip is attached to one side.
It is a phenomenon common in homes built with roof trusses as opposed to rafters.
