We recommend hot water because metal roofs can handle it and hot water is more effective.
Can you pressure wash a tin roof.
Always stand on a dry area of the roof as wet shingles can be very slippery.
Start with a medium pressure spray pattern and adjust from there accordingly.
You only need low pressure on metal roofs as it is enough to disturb and clean them.
Of course some chemicals can harm your roof as well and the runoff could cause problems with your landscape or parts of your home.
Most important though is to take some safety precautions before attempting to clean to reduce the chance of injury.
Pressure washing is very effective but may be best for metal or concrete roofs.
There is a chance that the pressurized water could damage your shingles.
Start off with a hot water pressure with a 40 degree tip.
Metal roofs are relatively easy to clean with patience.