back again, apart from advice given already, and not knowing the 'flag ' area covered, or what they are laid on, or perhaps into ?,,, or what is between each flag ? another way is to ( if possible ) lift one up, without chipping any of it edges, look at its underneath, can the flags be overturned and relaid ? altho' with older types. the best looking side was always ' on top ' still hard work lifting etc etc, but can save you cash, and any smells , if you can do it this way,,,,, hot soapy water, elbow grease.... remembering to ' seal them afterwards '