Spot marks on new paving slabs - Indian sandstone paving-polished kandia

[ashley.gendler@gmail.com]

Indian Sandstone Paving-Polished Kandia Grey Slabs

We purchased and had professionally laid the above paving slabs back in November 2016.

All the slabs provided were in good condition.

However last week we noticed small spot marks on four/five slabs in one particular area. It gives the impression that something has been spilt or dripped on them, but this is not the case.

The spot marks appear to be under the slabs themselves. We have tried cleaning with warm soapy water to no avail.

Does anyone know what this might be and can anyone give me some advice as to how we might get rid of the marks?

I can send photos by email if necessary.

Your help would be much appreciated.

[lemoncurd1702]

Sounds like they've been laid on spot beds i.e. a blob of cement in each corner and one in the centre.

[Tom - Westminster Stone]

Any images?

[Tony McC]

Like this - Reflective Staining

[Old Codger]

Indian Sandstone Paving-Polished Kandia Grey Slabs

We purchased and had professionally laid the above paving slabs back in November 2016.

All the slabs provided were in good condition.

However last week we noticed small spot marks on four/five slabs in one particular area. It gives the impression that something has been spilt or dripped on them, but this is not the case.

The spot marks appear to be under the slabs themselves. We have tried cleaning with warm soapy water to no avail.

Does anyone know what this might be and can anyone give me some advice as to how we might get rid of the marks?

I can send photos by email if necessary.

Your help would be much appreciated.

are they brown spots? If so it is probably rust staining from iron oxidising from within the stone.
if it is it can be cleaned.