Pressure washing slates

[bpowell555]

Hi, got a quote to redo the roof. The roofer suggests we could re-use most of the slates but they're covered in green, so I was wondering can they be cleaned up safely with a pressure washer? All the slates would be coming off so this would be pretty easy.

Not sure they're welsh slates but have been told they're good quality. Building is also listed so have to replace with same.

Cheers!

 

[Alastairreid]

It wont do any harm cleaning the slates with a pressure washer.

 

[Possel]

The roofer suggests we could re-use most of the slates

Be prepared to lose more than expected. I was told we would lose 30% and it was nearer 60%!

 

[seasickstevie]

I just use a scrubbing brush & bleach. Don't know if there's a better method.