Repairing Hardboard Lap Siding

The siding panels nearest to the ground are usually the first to mold.

Repairing hardboard lap siding.

Use a 4 foot level to check and then hammer in another nail. Immediately fill holes with a flexible all purpose filler such as pre mixed bridging and patching compound following label directions. Fortunately you can repair masonite hardboard siding with wood putty. If needed replace the sheathing behind the siding using 1 2 plywood covered with builder s felt or housewrap.

Be sure the top one goes through both boards. When washing allow it to dry completely for a day or two before treating or curating it further. You might notice bulging along the bottom edges a loose layer or soft. If you re replacing more than one board in a run simply hammer a nail into the top corner to support it and then move half way down the board.

Remove the deteriorated hardboard siding using a pry bar and chisel being careful not to damage the good siding above it. Remove the siding panel that is damage and install a fresh hardboard siding panel. Thick so set your blade depth carefully to avoid cutting into other courses. Finish the cut with a sharp utility knife.

Repairing hardboard siding if water seeps into joints between hardboard panels or penetrates through small holes it will cause the panels to deteriorate. Use shims to lift the boards so you can easily get at the one you re cutting. Check the siding panel for molds holes or any damage. If you can see black marks or streaks anywhere on your masonite siding it is a sure sign of being compromised by water.

Remove the damaged siding panel using a claw hammer and extract the nails left on the wall from the old panels using tin snips. Be sure to stagger the joints see photo 1. Make sure to scrub only the compromised area of the siding so that the structure remains unaffected. Then hammer away on the rest of the board.

Holes are a prominent problem with masonite siding.