When you say asbestos shingles i presume you mean asbestos siding shingles.
Pressure washer asbestos siding.
How to clean asbestos siding.
These are easily prepared and easy to repaint.
If you do power wash use as gentle a touch as possible and quit if you find that you re knocking pieces of siding off.
Mix one part bleach and three parts water and spray.
Power washing of asbestos wall tiles can be done but its condition must be considered first.
Avoid direct sunlight and let the detergent sit for 5 10 minutes.
Mix a mild detergent such as tide with water to make a cleaning solution.
For the toughest deep cleaning jobs consider 3100 psi pressure washers.
The use of a pressure washer for maintenance can crack the siding and lead to moisture intrusion if the pressure setting is high enough.
Asbestos cement can be dangerous if pulverized by sawing sanding breaking etc.
The power washer is going to release particles of asbestos regardless of how careful you are with it.
Only use a pressure washer at a distance of 6 feet or more.
This product cannot be refurbished unlike other forms of siding.
Clean up for something like this could cost even more money.
Commercial pressure washers are great for the toughest of stains and paint prep.
Place the detergent in the bucket and.
Although most of those particles will be trapped in the water while you are washing it the water will eventually evaporate and release those particles.
Now change the pressure washer nozzle to the 25 or 40 degree spray tip and wash away all the detergent while keeping the wand at least 1 foot away from your house siding.
Do not use a high pressure hose to clean fiber cement siding.
Apply the soap from the bottom up and rinse it away from the top down.
If there is fraying on the edges of the tiles the answer is no.
If you feel that you need to use a pressure washer especially on harder to reach locations only use it at a low pressure under 1500 psi with a wide tip.
Safety first when pressure washing.
Then as long as your using a lower pressure wand with the fan spray you will be fine.
You can power wash any loose paint or simply scrape and remove any.
This is one of the few ways that you can damage it.
Remove any biological growth such as moss and fungus from the surface of the siding.
It is difficult to find replacement siding for repairs.