You could get more than 100 years of service from a clay roof. Clay roofs need little maintenance, but a periodic cleanup will keep the roof looking good. These surfaces are more difficult to work on than wood or asphalt so you may defer any work to one of your local roofing contractors. But if you're the DIY kind of homeowner, here are some tips for keeping your clay roof protecting your home for decades.
A Question of Safety
Clay tiles become slippery when they are wet. If tiles have algae growing on them, they become even more dangerous to step on. Any clay roof above one story should be left to a roofing company. But if you can get to the tiles from a ladder against the house on a single story roof, you can do some of cleanup and repair work yourself.
Clay Tile Cleaning
Dirt and pollen can build up on a clay roof in dry climates where there is little rain to wash off the roof. If you live in a rainy climate and part of the roof stays in the shade, algae can grow in the damp areas. The algae sends tiny roots down into the clay and can crack the tiles if allowed to mature. These plants should be removed at the first sign of them.
Mix equal parts of water and chlorine in a sprayer and soak the tiles, especially any with visible algae on them. Use a brush or broom with a long handle to scrub the tiles gently. Use your garden hose to rinse off the tiles after scrubbing. Do not use a power washer, as you can force tiles off of the roof if you're not careful.
To clean large areas of algae or for areas that you can't reach from a ladder, have a roofing contractor do the work. They can work from the top of the roof down and use a power washer so it won't damage the tiles.
Repairing and Replacing Tiles
You can repair a tile should it become cracked by algae or a large piece of debris falling on the roof. Clean any dirt or algae off of the tile and let it dry. Use a roof sealer or silicone sealer to fill the crack. Clear silicone will be less obvious when viewed from the ground.
Broken tiles must be replaced. This is a challenging job because tiles are laid down from the bottom up, so tiles overlap each other where the fasteners attach the tile to the roof. To remove a broken tile, you must first break it up into smaller pieces that you can pull out from the overlapping tile. Carefully pull any exposed fasteners out of the roof where the old tile was positioned.
Use roofing compound or sealer to secure the new tile in place where you removed the old one. Apply a layer of the cement on the top of the new tile, and slip it under the overlapping tile. Use beads of the sealer to secure the lower edges of the tile to the roof and the tile being overlapped by the new tile. If you're careful where you place the roofing compound, you soon won't be able to tell the new tile from the old.
A Temporary Change in Appearance
When you replace a clay tile with a new one, you may see small white streaks on the tile for awhile. This is due to the reaction of the lime in the tile with oxygen and rain water. The streaks will wash away in a few weeks.