As you spray keep the distance of the pressure washer nozzle uniform across the roof.
How to pressure wash metal roof.
Use a cloth or sponge to clean.
For every part water combine 0 05 part mild dish or laundry detergent.
Pressure washing is very effective but may be best for metal or concrete roofs.
Start off with a hot water pressure with a 40 degree tip.
Opt for something soft to protect your roof s paint and parts.
However if you hire a seasoned company like fiddler roof cleaning you will have access to environmentally friendly cleaners such as eco roof.
Most of these substances can be removed by a mixture of cup tri sodium phosphate and 1 gallon of water.
There is a chance that the pressurized water could damage your shingles.
Cleaning a metal roof.
Of course some chemicals can harm your roof as well and the runoff could cause problems with your landscape or parts of your home.
We recommend hot water because metal roofs can handle it and hot water is more effective.
Mix water and mild detergent for stubborn areas.
Pine sap decaying leaves and even road dirt that s drifted into the air can settle on your metal roof and stain it.
For years many companies in the roofing industry have advised using a mixture of cup of tri sodium phosphate per one gallon of water.
You can also use a mild detergent solution in place of plain water if your roof is in particular need of a more intense wash.
You only need low pressure on metal roofs as it is enough to disturb and clean them.
This is very effective at getting rid of algae and mildew both of which often grow on metal roofs.
To remove severe rust stains.
5 parts water 1 part diluted hydrochloric acid or citric acid or muriatic acid or oxalic acid or vinegar.
For any areas that don t wash away with pressurized water fill a bucket or other container with water.
However keep the concentration of the detergent at its minimum.
Use a rag to apply to affected spots and use circular wiping motions.