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Sealing Natural Stone


LawnSite Member
Arlington, VA
Has anyone had experience using large boulders or large shale rocks in a water feature? We are looking at a job now where the customer wants to basically turn a natural shale/rock wall into a water feature.

A few items of concern:
Will the constant water cause the shale to flake?
Can an epoxy sealer prevent this?
Is there a commercial cleaner available for cleaning the stone initially?
Can the rock be bored run hoses/wires?

Any help or direction would be greatly appreciated.


LawnSite Fanatic
zone 7 CA
Yes rock can be bored or drilled with an impact drill and a big bit,just don't drill in the cracks and seams in the rock and start with a smaller bit and work up to a larger one.
You won't be able to seal the rock from water.It will leak and you will loose water.But you can put down a pond liner
on sand and stack the rocks on top,I wouldent recommend shale though as it will probably sluff of and clog up the pump.It is a soft rock.You could take a few pic's and post them and that would help show what you have going on.Then mabey help you figure it out.