Most homes around Perham benefit from a siding wash every 12 to 18 months. Shaded, tree-covered and lakefront properties often need it annually.
Concrete is different. Driveways and sidewalks look best on a yearly clean, mainly because of winter salt and tire traffic rather than organic growth.
Roofs are on a longer cycle — every three to five years for a soft wash, or sooner once you can see black streaking from the road.
Decks come down to your stain. Clean and re-seal every two to three years and the wood lasts dramatically longer.