One minor deck problem irked us for years: The finished surface of our decks was always a little uneven and synthetic decking often squeaked under foot. Setting the joists perfectly level at the house is easy, and the beam makes them fairly even near the front edge, but the problem is in the middle. Even though we use #1 PT lumber, the joists are often slightly warped or vary in depth, at times causing adjacent joists to differ in height by as much as 1⁄2 inch or more.
Our carpenter, Eric Roberts, has devised a simple, elegant solution. Before installing the mid-span blocking, he lays a straight 2x4 on edge across the deck and perpendicular to the joists. He then twists 6-inch TimberLok or HeadLok screws through the 2x4 “ridge” into each joist below, pulling the joists flush to the bottom of the ridge (see photo, above).
To preserve that consistent, level height, we nail mid-span blocking in place and secure each piece tightly with 4-inch TimberLok screws, two at each end (see photo, bottom right). When we are ready to begin decking, we remove the “Roberts Ridge.” A little movement and some squeak may still be noticeable in the frame, but installing the decking (especially diagonal decking) eliminates that. This simple process—which requires only a temporary 2x4 and some screws, and adds only about 20 minutes to a typical framing job—levels the deck, reduces deflection, and virtually eliminates noise.