I had an extensive bluestone patio installed 7 years ago by a very good stone mason. About 2 years ago, on the advice of a good stone quarry, I sealed with Compro MX to reduce the food stains and other associated problems that come from young twins. Last year I began to notice some flaking in a few spots. After this winter, I would say it's impacting most of the stones. Some it's just one layer, some it's multiple. Pictures below.

Any idea what's causing this? He hand picked the stones and they were all quite thick/solid from a good source. Did sealing this cause the problem?

More importantly, any idea how to make it stop? I've been "helping" the delamination process along but it seems to go on and on. I've read a bit about "thermaling" using an oxy-acetlyene torch and water. Think that might help?

Thanks in advance for any thoughts! So much $ invested in hardscaping and it looks horrible!

http://i1151.photobucket.com/albums/o634/ricoval/DSC_0191.jpg

http://i1151.photobucket.com/albums/o634/ricoval/DSC_0192.jpg