Treatment and prevention of moss on a flat roof

HOW TO REMOVE MOSS FROM A FLAT ROOF AND PREVENT RE-GROWTH

A flat roof can come in many different shapes, sizes and materials. Whether your roof is constructed from a standard 3-layer asphalt or from rubber-based compounds or even sheets they are all susceptible to the growth of moss. Roofs covered with stone chippings do tend to grow moss quicker than a roof coating with no stones because the chippings provide the moss with the perfect growing area; shade and moisture. Moss just loves shade and moisture and, if given both, moss will happily grow. The benefits that chippings bring to the roof surface, protection from frost and direct sunlight, also helps the moss spores to collect and grow.

The removal of moss from a flat roof is very important as moss will cause damage to many types of roof coating if allowed to grow as well as rolling into gutters which can cause blockages. More importantly, as many types of roof coating start to age they will slowly form small bumps and impressions. If moss can slowly grow on these areas then, as the surface expands and contracts with the effects of the weather, it will cause any small surface imperfections to open thus allowing water ingress. It is for these reasons that roof coatings should be kept free of moss and lichens.

The treatment of a flat roof is very straight forward and requires nothing more than a brush, bucket, sprayer and a good quality moss killer.

PREPARATION - MOSS REMOVAL

Preparation is the most important part of the cleaning and moss removal process. Given the construction of a flat roof you must to be careful where you walk, especially on an older surface. If you have any doubt about how safe your roof is then you should always contact a professional roofing contractor for their advice however a majority are fine to walk upon only with care. When walking on a flat roof, especially one covered with asphalt, we recommend ditching the high heels and wearing soft soled shoes. It is also a good idea to use a sheet of timber or wooden plank to stand on so that your weight is spread across the surface and you will not cause any damage. If timber is not available, then walk carefully across the surface.

If the roof has stone chippings, then brush them to one side which will remove much of the moss growth as well as allowing the roof surface to dry. If the roof has no chippings, then brush the surface to remove the growth and any debris such as leaves and twigs.

TREATMENT - MOSS KILLER APPLICATION

Once the roof surface is dry, spray the area with BATICLEAN CR - Concentrated Moss & Algae Killer which will kill any remaining growth and, most importantly, kill the spores. BATICLEAN CR is designed to be left upon the surface where it can help to inhibit re-growth. Please note that for the best results, BATICLEAN CR should only be sprayed on to a dry surface on a dry day. At this point you could collect the stone chippings in a bucket and rinse them which will remove dirt and any moss growth that may be present. Collecting the stone chippings is sometimes not possible so don't worry if you are not able to do this part of the process.

Once the BATICLEAN CR is dry, spread the chippings evenly across the roof surface and apply a second coat of BATICLEAN CR across the area ensuring that both the chippings and visible roof coating are covered. This second application means that both the covering itself and chippings have been coated with the moss killer.

FUTURE

You should always try and keep the area clear so remove leaves and anything else that could cause shade across the area especially during the winter months. Brushing the surface, occasionally, will help to inhibit moss growth and does not take too much effort. This will also ensure that any the stone chippings a spread evenly across the surface as, through time, they can move leaving areas of the roof covering exposed.

Given the nature of a flat roof water will settle, especially on older surfaces, therefore it may be required to repeat this moss killing process every 12-24 months by applying a new coat of BATICLEAN CR or, alternatively, just wait until the first signs of new moss growth appear before applying a new coat.

We have a full range of SPRAYERS and SPECIALIST BRUSHES that will help you with cleaning your flat roof.

PLEASE REMEMBER THAT WE ARE HERE TO HELP YOU. IF YOU WOULD LIKE ANY FURTHER ADVICE OR HELP WITH ANY OF OUR MOSS KILLING PRODUCTS THEN PLEASE DO NOT HESITATE TO CONTACT US.