How to Clean & Recondition Cedar Tongues & Grooves

Mix a phosphate-free detergent in a bucket with water according to the manufacturers instructions. Dip a soft bristled brush with a long handle into the mixture and scrub onto the cedar in the direction the siding runs to remove dirt. Rinse with cool water from a hose.

Mix powdered oxygen bleach in a bucket with water according to the manufacturer’s instructions. Wet a soft brush with a long pole handle into the solution and scrub back and forth across the tongue and groove siding to kill mold and mildew. Thoroughly rinse the siding with cool water from a hose.

Mix oxalic acid cleaning solution in a bucket with warm water according to the manufacturer’s instruction. Dip a clean rag into the solution and wipe across any rust or water stains. Allow the solution to dry on the surface. Mix two tablespoons of borax with one quart of hot water. Dip a clean rag into the solution and rub it along the treated areas to neutralize the acid. Allow the area to air dry before proceeding.

Dip a clean rag into a gallon of water repellant oil finish for cedar. Wipe the oil along the siding in long strokes in the direction of the grain. Allow the oil to fully penetrate for several days before further handling of the siding.