It is best to clean your siding twice a year, once in the spring and again in the fall.

Keeping your siding clean helps to keep your home beautiful for years to come and offers long-lasting protection against environmental pollutants and dirt that can build up and discolor the siding. 

Spring is a great time to clean the siding of your house. The warm, but not hot, weather makes the job easier. Cleaning the siding now helps to wash off the dirt, grit, & grime from the winter months and heavy winds.

Vinyl & Steel Siding—

  • If your house isn’t too dusty, sometimes all you need is a light spray from the garden hose and maybe a bit of dish soap (Dawn works great!) or a bit of laundry detergent (Tide is often a favorite). Work from the top down in manageable sections with a clear water rinse after wetting the siding and lightly scrubbing with a telescoping soft-bristled brush. Look in the RV section of your favorite store for a brush that will work. 
  • If you’ve got a bit more dirt build up and atmospheric dirt, you might want to make a solution of—
    • 1/3 cup detergent (Tide), 
    • 2/3 cup TSP (trisodium phosphate found in home improvement stores)
    • a gallon of water. 
    • Wet the siding as mentioned above, working horizontally in sections with the grain patterns, use a brush to apply the cleaning solution
    • follow with a clear rinse.
  • Mildew accumulation doesn’t happen often in Colorado, but shows up as small black spots. You’ll find that easier to tackle if you add a cup of bleach to the cleaning solution above and follow the same steps. Take care to not drip the solution on your clothes to avoid damage. 

James Hardie Fiber Cement Siding—

  • Always work from the top down. This keeps the dirt from washing off onto the siding you just cleaned.
  • A twice yearly rinse with the hose and a soft bristle brush is often all you’ll need.
  • Work horizontally in a side-to-side motion following the direction of the planks.
  • Please don’t use a high-pressure washer. That could damage the finish and the siding.
  • Avoid acid-based cleaners that can etch the color finish.
  • If you have a tough spot, add a bit of Dawn dish soap or Tide laundry soap to a bucket for cleaning. 

LP SmartSide Composite—

  • In the Spring & Fall, rinse the siding from the top down
  • Use a soft cloth, sponge, or soft brush
  • Work in the direction of the siding laps.
  • With tougher areas, again, the Dawn dish soap or Tide laundry soap makes an effective yet gentle cleaning solution.
  • Stay away from harsh, acid-based cleaners.
  • For mildew, add one part white vinegar to your cleaning solution.

Helpful Tips & Tricks

  1. Make sure all doors & windows are closed and locked so you don’t get water or cleaning solution inside.
  2. Use this time to also spray the exterior of the windows & the window screens. You’ll then just need to wipe up the droplets for a clear shine.
  3. For high jobs, always use care and wear non-slip shoes so you don’t slip on wet concrete.
  4. Eye protection goggles will keep any cleaning solution, bleach or vinegar from getting splashed back into your eyes.
  5. Work one side at a time, top to bottom. 
  6. No need to remove your shutters or house numbers since you aren’t using high pressure.
  7. Easily store a collapsible brush in the garage rafter for next time.
  8. Don’t let the dirt and pollutants build up, that could cause color fading and distortion.
  9. After cleaning the siding, open a few windows and let the musty winter air out and the clean spring air in. You won’t smell a dusty smell since the house was just washed.