Here's a brain teaser for home inspectors or anyone else who wants to take a stab. This has to do with roofing and attic.
The home is 8 years old.
There are a few nail pops in the roof covering, but not enough to cause concern.
The roof covering is asphalt shingles in good condition.
The sheathing is exposure 1 plywood.
The sheathing WAS NOT rained on between the time of installation and covering.
The spacing of the sheathing is done properly.
The roof structure is engineered roof truss with no defects in deflection, nor any cut trusses.
Attic ventilation is more than adequate, with soffit and gable vents with turbine assist.
Bath and other exhaust fans are properly installed, with no venting into attic.
All flashing is perfect, drip edge installed properly on rakes and fascia trim.
The roof has never leaked.
The problem: The roof is "wavy", bumps and rises in the sheathing.
The question is, "why?"