Continue spraying until you see runoff then let the chemicals sit for 15 20 minutes to soak in and begin attacking the mold.
How to remove mould from roof tiles.
If it is slimy or any sort of residue comes off on your hand repeat the above steps.
Choose a day when there is no rain forecast.
Spray the entire roof thoroughly.
Allow the solution to soak into the shingles for at least 15 minutes.
Roof mould is.
When mould is growing on top of your roof it is often indicative of problems that started within the home.
You must let the roof dry before a second application of mix.
The product needs to be diluted 1 part with 5 parts water in a garden sprayer.
Inspect the roof for any remaining fungus.
As you did in the previous step walk backwards when you are spraying away from the wet tiles and onto the dry ones.
Lichen on terracotta roof tiles is particularly unappealing to the eye and is best handled before it has a chance to cake in and ruin the tiles.
Next rinse the shingles thoroughly with a garden hose at low pressure.
If they are severely molded you may want to give it a little longer.
While it will not produce the same results as pressure cleaning it offers a quick and convenient option for cleaning the mould off your roof.
Cleaning due to evidence of permanent asphalt shingle damage caused by high pressure powerwashing.
Allow the roof to dry thoroughly.
More than likely it is spreading from your attic into your roof.
Start from the top shingle and rinse downward to prevent water seepage.
This will prevent the solution from draining in your direction.