Bonding for capstones - Capping stones on a retaining wall

[marty101]

Hi experts,
I need advice on sticking (bonding) capping stones to a retaining wall. The wall and caps are Anchor Diamond Sandstone - I spent a lot of time this summer building this wall and I don't want to stick the cap stones with some substandard product which will fall off in a years time - so has anyone got advice on what type of substance I should use.

Would you recommend epoxy mortar, admixture, and some type of silicone tube, or something else? Any products you can recommend would be gratefully accepted...

Cheers...

[lutonlagerlout]

it should be the same mortar you built the wall with mate
which should be 3 parts sand and 1 part cement
make sure to use the same sand and cement you built the wall with, or the colour may vary
cheers tony

[simeonronacrete]

If you want to be sure they stay there, add Ronafix to the mortar. Supplied as a liquid, use your 3:1 [sharp] sand:cement mortar, but instead of using just water, use a mix of 1:1 Ronafix : water and add this to the sand and cement to give the workability you want.

Before you place them, clean the surfaces, wire brush, damp with water, prime with 1:1 Ronafix and cement, then while primer is wet/sticky, lay the mortar bed and compact the capping stones into place.

If you want this mortar to match the bricklaying mortar, rake out the Ronafix mortar joints and repoint with your ordinary mortar.

For 1m2 of bonding at 10 mm thick you will need about 1.5 litres of Ronafix - and once stuck, it'll stay stuck. Better bond, waterproof, frostproof, vandal proof.

For stockists, try W T Burden, Adawall, Travis Perkins, Builders Centre, or call us on 01279 638 700.

Note of caution: don't get the mortar onto the exposed surface i.e. the visible face of the stone or the brick - it'll stick where you don't want it to stick.

Happy bonding.

[marty101]

Hi folks,
Thanks for the quick responses. There are a couple of things I should point out about my retaining wall.
1. It is a dry wall solution so no mortar required and for this reason
2. I would like to keep the application of the bond relatively thin - possibly 2-3mm but keep the bond strength to a maximum

Any suggestions...

[marty101]

BTW folks,
I've done some searching on the web and found a Liquid Nails product designed specifically for the job called Liquid Nails Landscape Block Adhesive. The problem is that it's not available outside the US as far as I am aware. Does anyone know of a similar product thats easy to pick up??

[simeonronacrete]

Suggest you go for the Ronafix; strictly speaking 3mm is too thin for such a mortar, but if you go for a fine sharp sand, you shoould be OK.