Stone Patio On A Supported Concrete Slab.

natural1

We are getting ready to install a cut stone patio in a random pattern on a supported slab. According to the GC on the project we need to water proof the slab before installation. I agree this needs to be done. I also feel we should have some type of anti-fracture membrane much like what is used in tile applications.

Does anyone recommend a product that can water proof, have anti-fracture properties and have at least 1" of mortar on top.

My second question is about expansion joints. The patio is about 350 square feet and probably needs to have expansion joints. The problem is the stone pattern is random using various size cut stone. So having a straight expansion joint running thru the stone will look stupid. I thought about incorporating some type of border to run along the expansion joint but I have not thought that thru yet.

Appreciate any opinions,

Thanks,
Mike

tkle

Use wide enough stones to span the expansion,then sawcut through them.Don't do a mudjoint.That said I rarely use an expansion,I use a membrane over the expansion and cracks in the slab. Cut borders of contrasting stone or brick look nice but do involve extra time.

natural1

Thanks Tkle. We decided to use a "system" designed by schluter systems. Basically it is a roofing membrane with some type of anti fracture membrane on top of that. Or we may use the uncoupling membrane which is often used in shower and tile applications. We also decided not to use expansion joints except where the patio meets the house and where the patio meets the brick ledger.

qualitywork1

xpansion joints dont have to be straight lines,,,,and u can begin ur pattern in accordance to them by starting your stones following the lines and working away from them,,,also there is a gritty mixture that can be applied to the surface of the stress lines as long as u make them 1 inch deep,,,it will make them blend alot better with your uniform look below the stones,,,,i hope that helps give u make a decision,,,,good luck