When I screed the sand layer, what should my elevation be with respect to the concrete surface that I want to be level with when finished? In other words, will the pavers "settle" down during compaction or afterward and if so, how much?? I've read numerous 'how to' articles/books/etc and have seen a lot of pics of similar installs, but nowhere is this mentioned. By the way I'm using reclaimed antique clay road pavers that are 4" x 9" x 3-3/4 thick that I aquired from a local construction project right outside my house!!! The gap spacing may be large due to the rustic shape of the pavers. Also, any recommendations on which type of saw to use??? Thanks, Todd H.