You have a 16 yr old roof with losts of moss.
Prsuure wash 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.
Never pressure wash your roof if you have asphalt shingles.
Pressure cleaning a roof when done properly using rotary cleaning equipment is safe cost effective and will not force water through or under tiles as the jet angle is controlled and always points away and down the roof rather than into or all over the place which is the case when blasting with a lance or wand is used.
Never aim your pressure washer up the roof as it can push water under the shingles.
Spraying water under your shingles can.
Aim the pressure washer down the roof toward the gutters and keep the tip of the wand at least a foot away from the surface when starting.
Most contractors don t recommend pressure washing or power washing a roof.
This is because the water comes out too forcefully and can damage the material.
See typical tasks and time to pressure wash roof along with per unit costs and material requirements.
Listen to everyone who posted here do not pressure wash your roof.
Always stand on a dry area of the roof as wet shingles can be very slippery.
Our soft wash tile roof cleaning process effectively cleans your roof without excessive pressure preserving your roof s warranty and ensuring longer roof life performance.
Instead soft washing with a garden hose is least likely to chip dent or crack the tiles or panels.
Pressure washing is very effective but may be best for metal or concrete roofs.
Not to mention using a pressure washer from a high place is dangerous.
If you can afford it especially if you have existing 3 tab on your roof almost to the end of its.
Once you squeeze the trigger the powerful recoil on the spray wand can throw you off balance and off of a ladder.
The cost to pressure wash roof starts at 0 33 0 40 per square foot but can vary significantly with site conditions and options.
The water pressure will remove the granules that are important for protecting your roof.
Get fair costs for your specific project requirements.
There is a chance that the pressurized water could damage your shingles.
Like rickengie i do the sweep as well as a flat bare to scrap the tough moss that a broom does not get and then use the moss be gone powder a day before the forecasted rain.
1 attach a 35 degree spray wand to the pressure washer hose and fill the pressure washer.