Areas of South Florida such as Palm Beach Gardens, Jupiter, and Boynton Beach are replete with neighborhoods with picky Homeowners Associations and tile roofs that get dirty. Dirty tile roofs and picky HOA’s a good combination do not make.
The “dirt” most homeowner’s see on their tile is actually algae. Because concrete tiles are porous, they absorb water and create a nice area for algae to take root. Slopes of the roof that get the least amount of sun get even more algae growth.
Many of our clients ask what we recommend for keeping their roof clean and keeping their HOA off their backs. We always recommend avoiding high-pressure washing methods. Tile roofs have many areas that water penetrates beyond the tile. A 3000psi jet of water that shoots into a crevice in your roof can cause damage by literally tearing or slicing right through the underlayment. With the underlayment damaged, your home becomes highly susceptible to roof leaks. Damaged roof tiles are another common issue after a roof cleaning. Because roof tiles are typically only supported by the tile below it, it is important to only step on the lower third of a tile. Always make sure you hire a professional to clean your roof and make sure they use methods that will not cost you more money in the long run.
There are options in roofing materials to avoid the algae buildup on tile roofs. When buying a new tile roof, avoid the “combed” flat tiles shown in the picture. These tiles have grooves that run through the surface of the tile, creating even more surface area and places for algae to grow. The other option is to select a clay tile roof. Although more expensive, clay tile is naturally algae resistant.