TRUSS UPLIFT

causes separation of the drywall

at the ceiling wall angle

PICTURE: What happens when truss uplift occurs

MAIN CAUSE

as prefabricated roof trusses dry, they shrink

since the bottom chord is surrounded by attic insulation

it's warm and drier and may shrink more than other chords

the top chords may actually lengthen in some circumstances

THIS MOVEMENT WILL CRACK THE DRYWALL

DRAWING: Bottom chord shrinks and crack the drywall

IS IT A STRUCTURAL PROBLEM ?

it is not condsided as a structural problem

cracks may open during the winter

and

close in the summer

because the truss is never completely stationary

WHAT HAS TO BE DONE?

NOTHING

however

a cove moulding can be installed to hide the cracks

attach the moulding to the truss chord only

DO NOT attach it to the wall partition

thus allows the moulding to move with the truss

and the crack will not be noticeable

PICTURE: Floating moulding will move with the truss and hide the crack