How to Prep a Wood Surface for Epoxy Floor Installation

A man installs a wood subfloor.
What You'll Need
Carpenter's 4-foot level
Electric sander
Extension cord
Sandpaper of various grits
Vacuum cleaner
Chlorine bleach
Flat-faced mop and bucket
Wood patching compound
Wood primer
Wood sealant
3-inch paintbrush
Lint-free low-nap roller on long handle
Eye protection
What You'll Need
Carpenter's 4-foot level
Electric sander
Extension cord
Sandpaper of various grits
Vacuum cleaner
Chlorine bleach
Flat-faced mop and bucket
Wood patching compound
Wood primer
Wood sealant
3-inch paintbrush
Lint-free low-nap roller on long handle
Eye protection

With careful preparation, you can successfully install an epoxy floor over a wood subfloor surface. Follow the steps below to prepare a wood subfloor surface correctly to install an epoxy floor.

Remove all Furnishings from the Floor Area

Take out all movable furnishings, cabinets, and bookshelves from the floor area to be prepared.

Clean the Floor Thoroughly

Mix a 10 percent solution of household chlorine bleach in warm water and mop the wood floor to kill and remove mold and mildew. Dry the floor with old towels and let it air-dry completely.

Sand and Level the Floor Surface

Using a power sander and 120-grit sandpaper, sand over the wood floor to remove splinters, chips, and fine cracks. Fill large cracks and splits with wood patching compound, and allow it to dry fully before continuing. Vacuum up all sawdust, dirt, and other dust with the vacuum cleaner. Check the entire floor surface for levelness with the carpenter's level. Sand down noticeably elevated areas and fill hollows with the patching compound. Then remove all dust before continuing.

Apply Wood Sealant

Apply a penetrating sealant to the wood to make it as moisture-resistant as possible. Any moisture remaining near the surface of the wood will penetrate the base of the epoxy floor and cause it to buckle and pop off. Use the paintbrush to delineate the edges of the wood floor with sealant. Use the roller to apply a sealant to the rest of the floor. Allow the wood sealant to dry for 12 hours before proceeding.

Apply Wood Primer

Use the type of primer recommended for the wood and for the best adhesion to an epoxy floor finish. Spread the primer around the edges of the floor with the 3-inch paintbrush. Create a strip about 4 feet long with each brushstroke to even out the primer effectively. Use a fresh roller on the long-handled roller applicator to cover the rest of the floor. Work with the wood grain when applying the wood primer.

Fill in Fine Cracks and Hollows

Run the roller against the wood grain with the primer to fill in fine cracks and hollows in the wood surface. Work toward the last wet edge to ensure the primer overlaps well.

Allow the Primer to Dry Thoroughly

Allow at least 8 hours for the coat of wood primer to dry thoroughly. Keep the doors and windows closed as the primer dries to minimize dust in the wet layers.

Choose a Flexible Epoxy

Wood will expand and contract according to the moisture in it while most epoxy finishes shrink and stretch with temperature. You can make the epoxy you use on your wood floor more flexible by adding a non-evaporating oil additive. Be sure to ask the flooring expert at your building center about how to make the epoxy over the wood subfloor more flexible, to help it last longer.