Sealing flagstone

by John Bohn
(Oceanside, CA)

I have a flagstone patio of abut 350 square feet. After sealing it with a wet-look sealer it did as you predicted, had large grey splotches where the alkaloids were coming up from underneath. I have painstakingly removed all of that sealer and power washed the patio. Two questions: 1. How long should I have to let the patio dry before applying the Porosco sealer (Siloxane PD) you recommend? 2. How many coats of the Porosco sealer should be applied, and how much time between coats? I cannot find any info on the Porosco website about coverage, i.e. square feet per gallon.

Many thanks for your help.


Comments for Sealing flagstone

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wait two weeks
by: David

Dear John,

My dad allows about two weeks for the patio to dry out before he applies Prosoco sealer. For 350 sq. feet, you should be able to get by with a couple of gallons.

You could buy a 5 gallon bucket and save it for later. My dad puts on one coat and it usually lasts a couple of years. Of course, the exposure to the elements has a lot to do with how long it lasts. When the water on the stone doesn't bubble up any more, then a new coat is probably warranted.

You can also call Prosoco at 1-800-255-4255 and they can give you a better description for your situation.

Great luck with your project!


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