Whats the best wood treatment to prevent mould

[Tom079555]

There was a hidden leak under my suspended timber floor. The timbers developed wet rot and the surrounding space became mouldy.

The area has now been replaced with fresh timber joists, and the leak has been fixed.

I'm concerned that mould could occur again. What is the best wood treatment to prevent mould growth for timber joists, and underside of floorboards?

Thanks!