On Mar 16, 10:15 am, wrote:
It's always best to remove all previous finishes before using any type
of waterproofing paint.

I'd also check if the Drylock product is even rated for exterior
application. AFAIK, it's used for interior basement wall
applications. The properties a paint needs for exterior use, exposure
to UV, weathering, etc, is different than those of interior paint.
And as has been pointed out, being thick, it's a bitch to apply. I
fail to see the point in wanting to use it for that application.