Sealing outdoor plywood keeps it from rotting and peeling and reduces its chances of mold and mildew. A water-resistant sealer takes only a few minutes to apply but needs to dry for several days. Plan for this drying time. Plywood is a flexible wood material with a variety of uses, from simple household projects to major construction tasks.
Set the plywood on the drop cloth. Put on the gloves.
Wipe any dust from the plywood with a rag.
Dip the paintbrush in the sealer. Brush the sealer onto the plywood, starting with the edges and moving inward to the surface.
Let the treated plywood dry for three days.