Using SDS drill to remove screw heads.

[xdave]

Do you have access to an impact driver? They will usually take out stubborn screws even when most of the head has cammed out. On really badly damaged heads use bits with serrated tips to get more grip. Wear eye protection incase the driver bit explodes/shatters.

 

[joe-90]

I can't see him going out buying a £300 impact driver, can you?

 

[xdave]

That's why I asked if he had access to one - maybe by borrowing from a mate. Most trades use them nowadays and most people know someone who is a either a builder, electrician, plumber, etc.

 

[xr4x4]

You can get a hand impact driver you know.

 

[maltaron]

Maybe teaching you to suck eggs but are you certain that you are using the correct pozi bit? If it does'n't fit properly it may be PZ3. Anything larger than No 10 screws are PZ3.