I have a stamped concrete patio that needs re-sealing. (for info: concrete poured with an integral color, then a dry-release was used on the surface.) Its just over 2 years old and the original sealer is flaking/looking worn.
The contractor sealed the patio as part of the project, but I don't know what kind of sealant was used, other than to say it has a semi-gloss appearance.
What I need to know is does it matter what sealer I use now, if I don't know what was on before? i.e. Acrylic vs. solvent based?
Do I need to strip what's on there to be safe?
ps. I've tried to contact the contractor but haven't had any luck getting a response.
more than likely it was solvent sealer used on the stamp work. two years is a little short of the life expectancy of these coatings on a light traffic area. this was probably due to sealing the concrete before it was cured or before the moisture level droped. this will happen with a lot of decorative concrete just because of the fact that once the stamp work is complete, the finished product needs to be protected asap. i would try to get a large enough chip of the coating and have it checked at a paint store. if you cant get a good chip off you can tect a small area with xylene. place about 1/2 oz of xylene on the coated surface and lightly rub it over about a 1 inch area. if the coating becomes gummy or starts to peel or blister, your coating is probably water base concrete sealer. if the coating gets a little tacky and polishes/shines up but dries back without any damage, it is probably solvent based. this test will only take a few seconds and read all of the warnings on skin exposure to xylene if you go this route.