I purchased Symphony Classic porcelain pavers in buff last year. The telephone service and delivery during a difficult year was excellent. Marshall’s recommend their own joining compound which is a brush-in hose-off grout. Despite following the instructions some grout has stuck to the pavers attracting dirt. Marshall’s were totally unhelpful & directed me to another company that supplies a grout remover. It would appear Marshall’s are aware their jointing compound is not fit for purpose but are reluctant to do anything about it. Such a shame when the pavers themselves are good quality and expensive. Photos show finished patio & resulting dirt from compound residue Incidentally our installers are Marshall’s & Bradstone approved