How to Clean Hardboard Siding

What You'll Need
Commercial or homemade meal do watch
Floor brush with a long handle
Mild laundry detergent
Water hose
High-pressure sprayer nozzle
Chlorine bleach
Steam cleaner optional but recommended
Rubber gloves
Safety goggles
Spray bottle
Paint or stain and painting tools

Hardboard siding is generally a more expensive alternative to vinyl or engineered wood siding and her is made out of wood fibers that are bonded together by resin. Although it is more expensive than some other types of siding, hardboard does usually last a bit longer if properly cared for and maintained. One of the most important aspects of properly maintaining hardboard signing is knowing how to properly clean it. Therefore, this simple how-to guide will show you everything you need to know in order to properly clean hardboard siding installed on your home. Let's get started.

Step 1 - Pre-rinse the Hardboard Siding

Attach the high-pressure spray nozzle to your garden or water hose and rinse the hardboard siding area that you wish to clean. Using the  high-pressure spray nozzle, attempt to remove as much dirt, dust and grime as possible before cleaning with soap and water.

Step 2- Scrub the Hardboard Siding

If you don't have access to a high-pressure steam cleaner, you can use a bucket of hot water and some mild laundry detergent to clean your hardboard siding. Fill the bucket with hot water and add about 1/3 cup of mild laundry detergent. Mix the solution until bubbles form and use the floor brush with a long handle to scrub the hardboard siding. When scrubbing the siding, you'll find it is much easier to work from side to side, rather than try to clean the hardboard siding by scrubbing up-and-down or in a vertical motion. When scrubbing the siding, don't attempt to clean too much at once. Stop every 6 to 8 feet or so and use the water hose and spray nozzle to rinse the soapy water away from the side of your home.

Step 3 - Clean and Treat Mildew Stains

Purchase a commercial mildew wash or create your own by adding one part bleach to four parts water. Add the mildew wash to a spray bottle and spray areas of the hardboard siding where the mildew stains appear. Once you spray on the solution, allow it to set in about 10 to 15 minutes, and then use the hot water and laundry detergent solution to scrub away the mildew stains. For particularly stubborn mildew stains, you may need to use a low grit sandpaper to sand away the stain. However, if you do need to use the sandpaper, be careful not to sand away too much of the surface from the hardboard siding.

Step 4 - Final Rinse

Once you've completed washing the hardboard siding, take the water hose and high pressure spray nozzle and give the hardboard siding on your home and final rinse.

Step 5 - Touch Up Paint or Stain

If you have used sandpaper or a abrasive scrub brush when cleaning the hardboard siding on your home, you may need to touch up paint or stain in areas where heavy stains were present. Use a paint brush to apply light coats of paint or stain to the affected area. Allow the paint or stain to dry about 30 minutes to one hour in between coats and continue applying the paint or stain until the color matches the exterior of your home.