Hi
I have been building myself a workshop and for one reason or another one side of it has been clad with treated shiplap longer than the rest. It has been exposed to the elements for about 6 months and now has staining along the bottom edge of each piece which I think is mildew. I want to apply cuprinol (anyone got any better ideas) but am concerned about doing it without treating the mildew first.
Should I treat the mildew first and if so with what, I don't want it to show through the wood treatment of course if possible.
Cheers
Andy Barron