Homeowners often invest a lot more in a tile roof than they would spend on asphalt shingles because of the increased durability and longevity of tile. However, you can only expect those tiles to last a long time if you put in the proper maintenance to keep them clean and free of moss and acids that eat away at the surface. Make sure you're keeping your tile roof clean the right way by following these five handy tips.

Control Pressure for Washing

Pressure washing may sound like the fastest and most effective way to clean off your roof, and in a way that's true. Yet using too much pressure on the tiles will cause cracking or at least roughen the surface to encourage faster algae and moss growth in the future. Using pressure that is below 1200 pounds per square inch is essential. A 1000 P.S.I. spray is usually more than enough to knock loose debris like chunks of moss and stuck on leaves. Instead of turning up the pressure to deal with stubborn stains and discoloration, it's better for the tile to use chemical treatments to remove the most stubborn dirt without damaging the material itself. When hiring a company to clean your roof, make sure they have the right equipment for low pressure and high volume cleaning.

Stick to Non-Bleach Products

Most tile roofs will need a cleaning product to remove discoloration caused by mildew and algae growth unless they've been cleaned every few years since installation. If you've skipped a few cleanings, a non-bleach roof cleaning product approved for clay or cement tiles should be sprayed on the surface and then rinsed off. Avoid bleach based products since they can speed up damage to the surface of the tiles, in addition to producing run-off that can damage plants and lighten the colors of surfaces below your roof's drip line.

Use High Water Volume

In addition to sticking with a low pressure spray, it's essential for the crew cleaning the roof to use a high volume nozzle on their sprayers so that plenty of water washes over the tiles. This encourages the removal of sticky debris without the need for a higher water pressure. It's also essential for rinsing away any lingering residue from the cleaning products that could build up on the tiles and cause unwanted side effects like chalking or color changes.

Plan Proper Intervals

It's best to clean your tile roof every few years or at the first signs of moss and algae growth. Each tile roof is different, so some may need cleaning annually while others can go five to ten years between cleanings. You should talk to your roofing contractor as they're installing it about how often you should have yours maintained. Factors that shorten the amount of time between washing appointments include:

  • Partial or full shade, which encourages growth of moss and algae alike
  • Overhanging trees that drop leaves and sap
  • High humidity for part or all of the year
  • Intricate roof design that involves a lot of valleys that gather water
  • Damaged or very old tiles that have a porous or crumbling surface.

Roof coatings that help repel the growth of moss and algae may help offset some of these factors to give you more time between cleanings.

Consider Air Cleaning

Finally, don't assume that low pressure washing is your only option for removing debris and dirt from a tile roof. If you'd prefer to keep water off of your roof as much as possible or are concerned about fragile tiles, air cleaning is also available from some companies. A high pressure jet of air does a lot less damage than the same stream of water when it hits the surface of a tile.