Are the worktops guaranteed?

Yes.  The materials are guaranteed against manufacturing defects from the supplier and the installation service against incorrect fitting for the lifetime of the product. 

Is any processing carried out on site?

Generally, no.  Our team would come to you to carry out a template prior to processing, and that is then completed at out factory unit.  On-site processing may consist of a minimal amount of cutting of upstands and possibly a small amount of polishing.  In some circumstances where installation is far away from our factory or where requested, on-site processing is possible.