View Full Version : Grout/mortar between granite pieces

06-27-2010, 09:15 AM
My new step project at my house is underway, my first. Looking ahead, I'm wondering what the best way to fill the joints between the pieces of granite on the top platform will be. There will be a full width granite tread at the start of the platform and the rest will be granite pieces in 1x1 and 1x2 squares. I thought of using poly sand like I would on a walkway but it would run out the sides where there is no border. Any thoughts?

06-27-2010, 09:45 AM
If you are on a flexible base than you are limited to something that wont crack like pea gravel, gatordust, etc. Actual mortar will only last if you are on a non flexible surface. You can just set up a temp edge to hold everything in or just grade up to the stones to minimize waste first. Regular poly wont work, but there are ones that are better for wide joints like gator dust, or you can do the gravel thing and get a binder for it. If you are solid you can use a grout bag.

06-27-2010, 09:50 AM
It is a flexible base. The outside pieces will sit on the block walls, but the center will be on a sand bed atop a crushed stone core. Is there some type of caulking that would work?

06-27-2010, 11:17 AM
just pour a pad and build the steps correctly. Make sure you flash against the house to avoid sill rot. I wold not use poly sand as it is to thick of a joint. Caulking and stone is just wrong. Mortar will be the best approach if its on a nice heavy compacted proper base as it will not shift. I wold pour a 4" pad pinned to the block walls and build up bt thats just me.