joesauers

Hi guys, I know this has been discussed before as I have done a search and read the replies. I still have a couple questions. I'd like to know if a 2'' overlay is sufficient, or if 3-4'' is required. (I have plenty of clearance at the doorway). Also, what prep is required. I read about grinding, is that required? Finally, is it necessary to drill any holes in the existing patio and drop a few 6-12'' long pieces of rebar in before the new pour to help hold everything together? The patio is 12' X 20'. The customer only wants a broom finish, no fancy stains or stamping. Thanks, Joe.

house bldr

While thin overlays can be done, you would have a better job less likely to crack with a 3-1/2" pour.No grinding needed,no pins to tie it together,in fact if the old patio is cracked excessively you may want to put a thin layer of sand over top so they don't bond as the new pour could crack in the same spots with any shifting.The only pins needed would be to tie the slab to the house if any settling has occured.12x20x3-1/2" should take 3 yards of concrete.