frost proofing mozaic

[Hazelb]

I'm putting in a pebble/ gravel moziac boarder on my patio. It is an an area that won't get much foot trafic. I used PVA in the mortar mix, but is there any thing I can use to seal the surface to stop water/frost from lossening the pebbles/gravel.
Is a coat of PVA good enough or should I use a silicon based product?

 

[TexMex]

Sealing an area of patio on top will not stop rising damp, (water being drawn up by capilliary action from below). I doubt that PVA in the mortar will prevent this either. Sealing the top could actually exacerbate the problem, as it will slow down the evaporation of this water. This would lead to more dampness in the surface than there would be otherwise. I'd suggest you ensure the area is well drained and leave the top surface well alone.