There are three common methods to clean your flat roof. However, all of them have their pros and cons and accordingly you should find out which method is more suitable for your flat roof. Most of the roofs are stained by algae and require regular cleaning to keep them looking good. Your worries would have been multiplied with a roof with shingles. But as flat roofs mostly do not have shingles, there is no need to worry about them.

The biggest problem with flat roof is of stagnant water after rainfall. Though most of the flat roofs are slightly slanted, which is of course not noticeable, yet water stagnates and becomes the cause of growth of moss and algae on it. If the moss or algae infected parts of your roof do not receive sunlight early in the morning then this algae does not die, instead it grows with the help of morning dew that has settled on your roof, further aggravating your problem of an unclean roof.

As said earlier, there are three ways in which you can clean your flat roof. A very common method is pressure cleaning. You can use a gasoline powered pressure washer. It delivers 2.4 gallons of water per minute and as a result releases a pressure of 2,500 pounds per square inch! You can equip the spray wand of the pressure washer with a 25-degree tip as used for general purpose cleaning. You can get astonishing results with this method of cleaning your flat roof.

All the dust, algae, moss and lichens that have covered your roof over a period of time will be removed. However, one thing to be kept in mind while using this method is that you should keep the spray wand tip close to the area to be cleaned, something like 6 inches from the surface. It is a very environment friendly way of cleaning your flat roof. It also saves you from investing your money in chemicals as required in other ways of cleaning your flat roof like chlorine solutions or sodium hydroxide base solutions.

Another way to clean your flat roof is with the help of chlorine solution washes. This procedure takes shorter duration to clean your flat roof. It requires much lesser time to rinse as compared to the other two methods. As a result the roof is saved from a lot of wear and tear due to prolonged hours of washing and cleaning. However, chlorine is toxic for some people and some plants as well. So care should be taken to keep them away when you are carrying out this procedure to save them from spray runoffs.

Another method of cleaning your roof is based on Sodium Hydroxide. Cleaners that have a base of Sodium Hydroxide are very effective as degreasers, but they need to be rinsed a lot as compared to chlorine solutions. This is not only time consuming but also involves a greater risk for your roof to be damaged. Sodium oxide is also toxic and should be kept away from coming in contact with property or persons. Plants should be especially kept away from Sodium Hydroxide. This chemical is also caustic and cause irreversible damage to your roof if used in high levels.