Clark Engineers was engaged by the owner of a restaurant that had excessive roof deflection (sag). The roof was constructed using premanufactured wood trusses.
Our investigation revealed that the gang nail plate connectors were slowly failing causing the sag. This permitted rain to pond on the roof causing the sag to increase and exacerbating the failure.
Clark Engineers designed a repair that included adding plywood sheathing to the existing trusses. After jacking them up to correct level to plywood was added to both sides of each truss. This is shown below.
The successful repairs are shown below.