Using romex rompox to solve a pointing problem - Advice required please

[andyp]

We had a natural limestone patio laid 4 months ago and this was laid on a dolomite base with a full bound mortar bed. The joints were then pointed by hand using traditional mortar with a black dye added to contrast nicely with the grey limestone. Unfortunately, the dye was not added evenly and we ended up with the pointing being very inconsistent in colour. The landscaper tried to resolve this by painting dye on top of the grouting and then adding a sealant over the grouting to seal the dye in. We were not happy when we saw what he had done to rectify this problem as it doesn't look very good and will apparently not last very long.

Now 4 months on we have the added problem that the mortar pointing has begun to break away into large pieces in places. We are unsure why this has happened but it is in areas of the patio where rainwater seems more prone to accumulate.

The landscaper has decided that the best way to solve the above problems is to remove the old mortar pointing and has suggested re-pointing the patio using Romex Rompox Easy. Whilst this looks a very good product, I am concerned that this may not be suitable for the bound mortar base that was laid when the patio was done 4 months ago. Romex state that the product is a "highly water permeable fixing mortar that allows rainwater to seep into the ground" and "that is should only be used on surfaces with a water permeable foundation as if water is allowed to stand in the joints, the Rompox compound will break down". The landscaper has said that they will remove part of the original mortar pointing (a few centimetres) and then fill the joints with the Rompox product but the mortar bed will still be in tact below. Will this be ok? Or will water penetrate through the Rompox product but then sit in the joints on top of the mortar bed and cause the Rompox product to break down.

Obviously, we don't want to create further problems for ourselves and would value second opinions. Whilst our landscaper is trying to help, our trust levels have dropped after the above problems. Please could you advise us?
Thank you

[lutonlagerlout]

why is rainwater "accumulating" on your patio?
romex wont stop that happening if its laid over a solid base,
LLL

[andyp]

Thanks for your reply.
I think the rainwater is accumulating in that area of the patio due to perhaps the fall of the patio being a little out. To be honest though, the rainwater that accumulates is very minimal and does soak away in a few hours. This may not be linked to the crumbling mortar pointing and it may just be coincidence.

My main concerns are whether the Romex Rompox Easy compound will be suitable as replacement pointing for the patio when we have a full mortar bed as it says that a permeable foundation is required.

[Tony McC]

I'd 'upgrade' to one of the full resin-bound products, such as D1, rather than risk it with the Easy, which, as you've said, is primarily intended for free-draining patio applications.

[andyp]

Thanks for your advice Tony...