sealing slate to prevent flaking
by David Elam
(Chapel Hill, NC)
We want to install an Indian slate. What is the best sealer to use to prevent/minimize flaking or dusting.
I recommend using the enhancing sealer, as it's a penetrating sealer and will not flake like a topical coating.
I never recommend any coating on any natural stone.
The difference between a topical coating and a penetrating sealer is, the penetrating sealer absorbs into the stone and a topical coating stays on top and covers the stone.
If you use a topical coating, you will have problems with flaking with exposure to the sun.
Usually topical coatings will leave a shiny finish, and to me, looks plastic or fake.
The enhancing sealer is a penetrating sealer and will leave the stone a little darker, but not shiny.
With slate we always recommend the enhancing sealer as it darkens and brings out the colors of the slate.
These are my opinions based on my experience.
I hope this helps.