Black spots on “new� riven york stone - Advice please

[cb35]

I’ve had a patio built from new riven york stone, including both paving and walling. It all looks great except the contractor has had to have the pillar pier caps remade so many times that the original stone supplier has run out of material of the right colour.

So they’ve gone to another stone supplier and had another set of pier caps made. They’re the right shape and size this time, but they all have small (1mm) black spots on the surface to some degree. The paving, walling and copings are clean so the spots on the pier caps are quite noticeable right now. Comparing with the pictures on this very helpful site it looks suspiciously like these "new" pier caps are in the early stages of black lichen spotting.

Would it be reasonable for me to make a fuss (again) and get them to make them (yet again) from new stone? Or should I accept that my lovely fresh new patio probably won’t stay looking this way, so I won’t notice the spotty pier caps in a year or two?

Thanks

[Tony McC]

I'd make a fuss withy the supplier. Why should you accept something that is, technically, "dirty"?

There are plenty of proprietary black spot renovers on the market, but use them with care as some will adversely affect the colouring of some types of stone. Dilute bleach is usually the safer option.