Swimming pool coping slabs - Laying pool coping stone

[Explorer]

In the process of refurbishing an inground concrete pool that has suffered frost damage to the tiling line at the top. Most of the large bullnose coping stones around the edge are loose so need resetting. Only want to do this job once and the right way ! Intend to use 1 part cement / 3 part sand plus plasticiser / waterproofer to make the mortar mix to bed the stones.

Can anyone advise if this is the correct mortar mix to use - the stones will be bedded directly onto the concrete pool shell and must not move once fixed in place.

Many thanks

[lutonlagerlout]

I would use grit sand and prime the surfaces with SBR
also add SBR to the mix
LLL

[Explorer]

Many thanks LLL. I have exchanged my waterproofer / plasticiser for the SBR you suggest. Do you just paint the stone surfaces with SBR prior to laying ?

What is the benefit of using grit sand as opposed to building sand - thought I would get better bonding / adhesion with the softer sand mix ?

Thanks

[TheRockConcreting]

What is the benefit of using grit sand as opposed to building sand - thought I would get better bonding / adhesion with the softer sand mix ?

Building sand has a high clay/silt content and is very weak, sharp sand is what you need like LLL said.

[lutonlagerlout]

mix sbr with water into a slurry then paint both surfaces before then adding your grit sand mortar and bedding
LLL

[Explorer]

Many thanks to you both for your advice - sharp / grit sand it is then. That SBR really is sticky stuff too !

Cheers.