Sometimes, but it's not usually the best move. Pavers can be set on top of an existing concrete slab using a thin bedding layer instead of a full compacted base, but a solid slab doesn't drain the way a proper paver base does, so water can get trapped underneath and cause problems the original patio never had, especially through Blue Ridge freeze-thaw winters.
The slab has to be structurally sound and properly sloped for this to work at all, and pavers are typically set on top of it with a thin bedding layer rather than the deeper compacted base a ground-level patio would get. The catch is drainage. Water that gets between the pavers and the slab has nowhere to go except sit there, and if it freezes in place over the winter, it can push up on the pavers from below in the same way freeze-thaw damages any trapped water in masonry.
There are situations where it makes sense: a slab that's sound, well-sloped, and where the joints and edges can be detailed carefully to keep water from getting underneath. There are also situations where it's a bad idea, a slab with cracking, heaving, or low spots that already hold water, or one near the house where trapped moisture could work its way toward the foundation.
We inspect the existing slab before recommending anything, checking its condition, how well it currently sheds water, and how close it sits to the house. Often we'll recommend removing the slab and building a proper base instead, because a base that doesn't drain right up here tends to fail faster than one built from the ground up.
More on this from Chelo's Brick & Stone.
Chelo's Brick & Stone serves Hillsville, Galax, Wytheville, Fancy Gap, and Independence, VA. Call for a straight answer and a free on-site estimate.
