Paving over old patio.

[J_N30]

I know as a general this is frowned upon due to the unknown sub base but would it be okay to lay new 20mm porcelain tiles over an exciting patio that is laid on block and beam.

The foundation is obviously solid.

Thoughts? Thanks!

 

[blup]

Tiles can crack if they not properly bonded but equally can flex if they are stuck down without proper allowance for movement. That applies more so in a damp external location with a retained layer of old slabs. So there must be a greater risk of movement which can be minimised with careful preparation, but not entirely excluded. Use of flexible membranes and adhesives can only help