There is also a risk of flooding to the loft space.
Pressure clean roofs.
Time and care must be taken to wash every inch of a roof including gutters and drainpipes but the end result is well worth it.
While specialized eco friendly roof cleaners are available they are a little more expensive.
Most contractors don t recommend pressure washing or power washing a roof.
Pressure washing in which highly pressurized water is sprayed on the roof to remove any mold algae dirt or grime and chemical cleaning sometimes called soft washing in which chemicals are the main thing that are removing those harmful things from your roof.
Make sure to build up pressure.
A home cleaner can be made with a quart 95 l of standard laundry bleach and a gallon 3 8 l of water.
Instead spray down the roof with a cleaner that kills mold and moss or apply a 50 50 mixture of bleach and water in a pump sprayer and let the moss die on its own.
Optionally add cup 177 5 ml of a non ammonia heavy cleaner such as tsp trisodium phosphate for extra cleaning power.
This is very effective at getting rid of algae and mildew both of which often grow on metal roofs.
This is because the water comes out too forcefully and can damage the material.
Metal roofs are relatively easy to clean with patience.
Each of these methods has their strengths and their own shortcomings.
Roof guard is able to provide roof cleaning for a range of roof varieties and materials from concrete and terracotta to polycarbonate and metal.
Use low pressure to spray it clean the power of a pressure washer can damage the shingles on your roof so it s important that you select the proper spray tip.
Start with a medium pressure spray pattern and adjust from there accordingly.
As stated by several roof tile manufacturers and the uk s trading standards organization pressure washers can damage roof tiles strip the surface granules from the tiles and shorten tile life expectancy.
Instead soft washing with a garden hose is least likely to chip dent or crack the tiles or panels.
In most cases all you need is pressurized water but sometimes you may need a chemical cleaner for especially tough spots.
Start off with a hot water pressure with a 40 degree tip.
Of laundry strength liquid chlorine bleach and water.
Most important though is to take some safety precautions before attempting to clean to reduce the chance of injury.
We recommend hot water because metal roofs can handle it and hot water is more effective.
Read more about why pressure washing a roof is a very stupid thing to do.
Always stand on a dry area of the roof as wet shingles can be very slippery.
You only need low pressure on metal roofs as it is enough to disturb and clean them.
