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I’m wondering if anyone has tried this. I’d like to add slate, flatsone or even cultered stone onto an exterior sidewalk. I think it would give an awesome look. Do you think it can be done with some kind of high-lime mortor (for a good bond) or some other construction adhesive? If I pointed in between, do you think it would even stick to the old concrete? I have over 6 inches verticle to work with. Thanks in advance for any info.
Kirk
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Kirk, do you mean you plan on raising the existing elevation 6"?
While you're at it,can you tell me if you have considered the control joints in the sidewalk?
*No. It can be thinnner, it's just that if over 6" it'll start being higher than the driveway and look wierd. I didn't think of the control joints but the original walk only has these indented grooves, I guess to "entice" it to crack there. maybe my joints can line up with these. Thanks for your reply Rich.Kirk
*Well, for what you plan to do, I'd say set the stone pavers in wet mud. Wet the sidewalk and while there is standing water, liberally sprinkle on pure cement. Swish this into a slurry using an old broom. You have just made a "neat" coat. Back butter each paver with a neat coat--or thinset mortar--and set into wet mud.Don't do any of the above until you have completed your layout and have established your elevations, fall, etc.Have fun!
*1) After being sure the underlying concrete is sound I'd scarify it or acid wash it and then rinse it well. I agree about setting it in mud but I'd use a "dry pack" mud, 3 sand:1 portland: just enough water so that when you squeeze a lump of the mix in your hand it's solid and if you rub it with a trowel water comes to the surface. I also agree about painting the concrete surface with a "neat" mix (and the stone surface too, use a wallpaper brush) but I'd add generous amounts of a "concrete bonder." The thin latex versions work well but are very expensive. I've had good results with Borden's Concrete Bonder which is less expensive and more widely available in lumber yards and builder's centers. (It looks and smells just like Elmer's white glue and I've never been able to find out if it's the same stuff or a different formulation). Maybe 1 water:1 bonder in this neat paint. You can also use a greater dilution of the bonder in the mud. Think in terms of using gallons of the bonder, not pints.It's not the traditional way and it's trickier work, but you can use this dry pack mud in the joints as well and fill them as you set the stones so there's no seam or fracture plane between bed and joint grout. Be sure to slick or finish your joints before you get too far ahead with other work and the mud gets too hard and be sure to wipe the stones clean BEFORE the concrete with bonder sets up! I did this with slate which is slick, if you're going to use a flagstone or other textured or unplosihed surface I'd test the dry pack with bonder on a scrap to see if you can wash it out of the nooks and crannies before going ahead on the actual walk surface.2) I've done flag and slate walks over poured and reinforced bases without control or expansion joints and they've stood up well. I've also seen flagstone jobs that have popped and separated, I think it's base preparation and reinforcement that's key..... Well, now come to think of it there may have been control joints in the base but definitely not in the stone surface. Longest run was about 20Ft.I did a slate walk as described at 1 & 2 10 years ago this coming Fall. Part new base, part over old. I walk on it every day and it's still tight as a drum. No loose grout, no popped slates, no cracks beyond cosmetic hairlines. This is in SE NY with typical seasonal weather extremes and freeze thaw cycles.