Can I Put New Sheathing Over Old Flooring?

Tile

• Removing old tile can be extremely difficult, especially if that tile was set into a thick mortar bed instead of cement board. Modern tile installations use plywood and cement board sheathing to support the tile and only a small amount of mortar. You can lay new tile directly over old tile without any extra sheathing, as long as the old floor is clean and in good shape. You may need a layer of sheathing over damaged floors.

Wood

• Antique hardwood floors are prized by many homeowners, but they might not be right for your situation. If you want to put in a new floor, but don't want to remove existing hardwood, you can add a layer of oriented strand board, or OSB, sheathing to support carpet, wood laminate and other modern, low-maintenance materials. If the existing wood is uneven or severely damaged, you'll still have to level and repair it before resheathing. Extra sheathing can also reduce bounce in second-story wood floors, according to Fine Homebuilding.

Asbestos Tile

• Many old building materials, including some kinds of linoleum and vinyl tile, contain asbestos as a fire retardant. This material is extremely hazardous to human health. When possible, cover it instead of removing it. Have old flooring tested for asbestos before you pull it up. If the test comes back positive, cover the old floor with a layer of sheathing, and then add new linoleum, tile, laminate or carpet on top.

Considerations

• Except in cases where removal would cause a health risk, the finished floor will always be better if you remove the old one. Adding new sheathing also raises the floor slightly and can shorten doorways or ceilings uncomfortably in some old houses. Lay a new floor over the old one only when it's prohibitive or dangerous to remove the existing materials.