Plastic sawhorses are a functional and economical tool for use when constructing a work surface. Plastic sawhorses exposed to extreme summer heat tend to distort and sag. This method will add the needed strength equal to that of the wooden sawhorses. Strengthening plastic sawhorses can be accomplished by adding strips to the legs, allowing for more weight capacity, preventing the plastic from distorting under extreme temperatures.
Common economy grade 2 by 4’s ripped in half will be used to provide the additional strength.
Start by measuring the length of the sawhorse legs. Subtract 2 inches from the measurement and use a power saw to cut the 2 by 4’s to the calculated length. Rip the 2 by 4’s in half with the power saw, creating pieces 2-inches shorter than the length of the sawhorse legs, creating pieces 1-1/2 by 1-3/4-inches thick by the calculated length.
Clamp each piece 1-inch from the top of the sawhorse leg and fasten the ripped 2 by 4 through the back of the plastic leg with 1-1/4-inch drywall screws. Install approximately four screws in each piece.
The use of large washers will prevent the screw head from penetrating the plastic sawhorse leg.
The use of a wood top rail screwed to the surface of the sawhorse will enable the saw blade to pass through the work piece without damaging the plastic rail of the sawhorses. Use the same cutting method and material as used for the legs to make the top rails. Cutting the wood rail 12-inches longer than the length of the plastic sawhorse rail will allow for greater stability when cutting larger work pieces.
Applying a protective finish to the added wood, although not imperative, will preserve the integrity and prevent warping. Exterior paint or polyurethane is well suited for this application.