How to Get Rid of Bowing in Plywood

Set Up

• 1

  Unstack the plywood, or remove weight from it. Allow the plywood to sit on a flat, dry surface for 24 hours. Inspect the sheets to see if the bowing has corrected itself. If not proceed to the next step.

• 2

  Wet enough towels to cover the surface of the bowed plywood in hot water. Wring the towels out until they are just damp. Lay them out on a warm concrete surface, such as a driveway or patio in full sun. Allow the towels to set in the sun for one hour.

• 3

  Turn the plywood panels so that the concave, or bowed in, face is down and lay them out on top of the towels, so that the moist heat from the towels begins to expand the grain.

Straightening Panels

• 4

  Cut heavy duty black plastic sheeting to fit on top of the plywood panels, using a utility knife. Allow the plastic to warm up, increasing the effect of the moisture on the bottom of the panel and the dry heat on top. Allow the panels to set like this for two to four hours. Inspect the panels to see if the bow is sufficiently straightened. If not, continue.

• 5

  Replace the black plastic sheeting on top of the plywood and rest cinder blocks on top of the plastic to press it flat. Leave the panels in this position until the panels are straight enough for use.

• 6

  Remove the cinder blocks, careful not to scratch or ding the plywood. Lift the panels up off of the damp towels and stack the panels with 2-by-4 skids between each sheet, every 18 inches to keep them level. Allow the panels to dry completely before installing or cutting.