best way to put flagstone on top of concrete?

Answer 1

Here u go, I just did this summer...don't worry about the concrete base, as long as its solid, not pitted or breaking up....

I did option 1 for a small bbq area in center of yard, and then option 2 for a patio next to house.......first, option 1 - they sell it home depot, called stone dust...Use about a 2-3 inch bed, level, place flagstones down, and then tamp in place....then spread remaining dust in joints and spray with water, forms a decent bond. You can also joint with a 2/3 portland cement 1/3 sand mixture, but either way you'll probably have to re-adjust a few stones every year or two, to get level after a winter or heavy rains.

For something a little more permanent, you can use a 3" mortar bed over the cement, but make sure to extend expansion joints if its larger than an 8ft area. Use an adhesive referred to as milk to prep the original concrete for adhesion. you'll also need to "butter" the flagstones with a 100% portland cement slurry(mix to a consistency of a milkshake) to ensure a good bond between the mortar and then stones. then joint the flagstone with a 2/3 1/3 mix noted above.

Make sure you clean flagstone off quickly as you work so that mortar doesn't dry on top of stones, tougher to get off when its dry.

Answer 2

you would not normally put flagstone on top of concrete there is an extreme likelihood that they would eventually break from any slight unevenness.you could put a few inches of sand over the concrete and then lay the flagstone or do what i did get a sledge hammer and think angry thoughts the concrete wont stand a chance. PS wear eye protection.

Answer 3

with cement, buy ready mixed mortar or use portland II and sand 1bag of cement will need about 17 shovels of sand use the dot method a ball of cement on each corner and 1 in the center mix it wet it will help keep it even and the wetter the cement the easyier it will squish down but not to wet so it looses it's plastic like feel when your done point the joints with cement die it if you don't like the look but this is where most of your streghth is so don't skip this step also back up the edges with cement. MOST IMPORTANT CLEAN WITH A SPONGE AS YOU GO. LATER IF YOU HAVE SOME CEMENT ON THE STONES USE MURIATIC ACID IT WILL TOTAL EAT THE CEMENT BUT NOT THE STONE. I've set with other materials but in the end we told all customers cement is the most reliable Do not use glue! mortar is the best. remeber the stones will vary in thickness. Set in cement we use 1" thick, 2" if set in stonedust

Answer 4

You wouldnt usually put stone on top of concrete, but you could start by ripping up the concrete.


You could get some heavy duty adhesive to glue the stones down, then use something for the joints in between.

Answer 5

Sure, as long as the concrete has structural integrity and the new flagstone is not higher than your home's slab or floor height (if patio is attached to home).

Answer 6

Have the concrete resurfaced, stamped and colored to look like flagstone.

Answer 7

You could put either packed sand or minus rock on top of the concrete. Then place flag stone into that.

Answer 8

concrete won't adhere to concrete!