Most people think that if a roof doesn’t leak, the maintenance and replacement work will be unnecessary. But it is probably mistaken. Similar to our family cars, roof should be regularly maintained and cleaned. Especially moss, if left untreated, it will block the water path and trap water which will result in a hidden problem: water leakage. At the initial stage of leaking, you can hardly notice it since the small amount of water would be absorbed by wood and heat-insulated foam. If this situation persists, the roof structure will be deeply affected. When leaking has become more serious, water will drip through the ceiling. At that time, the ceiling, even the floor, furniture and the kitchen utensils will need to be replaced. Consequently, the loss caused by the leaking will be greatly increased. Therefore, roof should be regularly maintained and cleaned. As for replacement, we need to make a concrete analysis of a concrete situation. When the wood shakes are out of shape and warped, or crack and rot, you may have to consider replacing the wood roof. If you find your tile roofing covered with large quantity of moss and there are cracks on the surface of asphalt, the tile roofing may need to be replaced.

A pitched roof is usually covered with asphalt shingles. This sort of roofing contains asphalt and fine gravels. These gravels are there for two reasons. The primary reason is to protect the shingles from the sun. In inland areas of Ontario, sunlight is the biggest enemy of roof since the sun's UV rays are very damaging to asphalt and cause it to deteriorate prematurely. While in western areas, especially in Vancouver, too much rainfall is the biggest reason for roof leaking. When you observe your roof, you will find the most terrible condition usually exists in the northern part and shaded places (e.g. the place sheltered by a tree). The condition of such places is also the decisive factor whether the roof should be replaced or not.