I wish I'd done mine from the outset! I have 140sqm tegular blocks, front side and rear. I had it done because I was under the misapprehension block paving is 'maintenance free'. As you know, it bloody well isn't in it's untreated form!
Anyway, after 4 years I had it cleaned pristine, re-sanded and finished with Resiblock 22. In over 2 years (3 summers) I haven't seen a single weed, and that includes the marestail!
I can only say this stuff has made me like the paving again, because I was beginning to go mad with it previously. In fact, it has brought it's own problem - now when the dogs go outside for a wee, it stays totally on the surface as it's got nowhere to drain away! I have to constantly follow with the hose and a squeegee to get rid of it!
Anyway, after 4 years I had it cleaned pristine, re-sanded and finished with Resiblock 22. In over 2 years (3 summers) I haven't seen a single weed, and that includes the marestail!
I can only say this stuff has made me like the paving again, because I was beginning to go mad with it previously. In fact, it has brought it's own problem - now when the dogs go outside for a wee, it stays totally on the surface as it's got nowhere to drain away! I have to constantly follow with the hose and a squeegee to get rid of it!