Screen doors come in handy when the weather turns warmer, allowing fresh air to enter your home and saving you money on air conditioning bills. A screen door can be constructed of wood, aluminum or vinyl. Due to the lightness of construction of a screen door, over time it can sag or warp. You can straighten the door back to its original shape in most cases by installing a brace that has a turnbuckle. The brace is mounted diagonally on the screen door and has two threaded rods on each end. The turnbuckle connects the two threaded rods and when turned, pulls the door back into shape.
Assemble the screen door brace by screwing the threaded rods into each end of the turnbuckle approximately ½ inch.
Open the screen door and place wooden blocks under the outer edge of the door if your screen door is sagging. Place enough blocks under the edge to bring the outer edge of the door upwards until it is level. Check the door's angle by placing a small level on the door's center cross brace.
Hold the turnbuckle brace assembly to the inside of the door. Make sure to position the lower mounting hole in the brace in the center of the lower door cross member. Mark the hole with a pencil. Remove the brace and drill a pilot hole using a 1/8-inch drill bit and an electric drill.
Hold the brace to the door and thread a screw (included with the brace) through the lower mounting hole in the brace and into the hole drilled into the door. Do not tighten the screw yet.
Rotate the brace upwards until the upper mounting hole is centered in the structural side member of the door that the hinges are mounted to. Mark the hole with a pencil and drill a 1/8-inch pilot hole as in the above steps. Secure the upper mounting hole in the brace to the hole drilled with a screw tightened with a Philips screwdriver. Now tighten the screw in the lower brace mounting hole.
Turn the center sleeve of the turnbuckle in a clockwise direction either using an adjustable wrench or a nail inserted into a hole in the sleeve. Remove the wood blocks from under the door and close it, checking the gaps around the door for rubbing. Rotate the center sleeve of the turnbuckle in a clockwise direction until the door closes smoothly without rubbing.