How to Use Hardwood Sleepers for Decking

Lay the hardwood lumber on its wide edge on the roof or slab. Check that it is horizontal with a spirit level. Shim one end or in several spots if necessary to make the sleeper level. Lay additional sleepers every 24 inches until you have covered the deck surface. If you have a significantly sloped surface, turn the hardwood sleepers sideways on their narrow edges. Scribe them with a pencil compass and cut them with a circular saw on the bottom edge to make the top edge level. Lay the hardwood sleepers 16 inches apart instead for a sloped roof.

Continue to shim as necessary so that all the sleepers are level across the length and width of the deck area and in comparison to each other.

Lay strips of EPDM rubber between each sleeper or shim where it contacts the roof surface if you are laying sleepers over a rubber roof. Fasten the sleepers with concrete screws or a power hammer if your sleepers are set over a concrete slab.

Lay 5/4-inch decking perpendicular to the sleepers. Fasten with two galvanized deck screws at each sleeper, treating the sleepers as you would joists on a standard deck. Finish the edges with 2-by-4 skirt boards -- which can match the wood type and shading of either the sleepers or the decking -- set vertically, aligned with the top of the end deck board and fastened to it with deck screws.