Specifications include, but are not limited to: 1717 - INSTALL MISC - Supply/Install per SF Concrete Sidewalk Pad for trikes and around play area (6.25" Thick Concrete over 4" Stone). Should be minimum 3500 psi concrete with fiber. (Reason for the 6.25” of concrete; this pad extends up above the lower pad to allow for a flush tile installation. Doing the thicker concrete around it makes easier job for installer putting concrete in.) 2401 - INSTALL MISC - Supply/Install per SF 4" Concrete over 4" Stone Base for Tile (this is same 3500 psi concrete with fiber) Also, this is the concrete area that is under the tiles in the playground “islands.” Top of this concrete must be very smooth and flat for tiles to adhere. Multiple weep holes in bottom of this area to be drilled after pouring to allow for water to escape (You will have 4” of stone on entire bottom of area and where the tiles are, 4” of concrete as the base. Around the tiles the concrete would be thicker, at 6.25”, to allow for a flush edge with top of tiles and concrete.) Excavation of area…entire area (approx. 4118 sf) to be excavated out at 10.25” deep and all spoils hauled off site for disposal. This is based on 10.25” below the edge of the sidewalk beside the building and total area should not slope more than 1% from there outward to far end of area. We were estimating the amount of material being removed and it may be slightly more or slightly less. The starting point of 10.25” down is the most important, and the slope going out from that point. Drains 75 linear ft. of standard trench drain (felt, 4” perf PVC pipe and gravel) between existing sidewalk and new concrete area (will need a short concrete bridge connecting the sidewalk to the concrete play area). Trench drain to connect to hard plastic 4” PVC and run approx. 80 lf from trench drain to daylight. We had also estimated some internal drains from pit (island) areas out to trench, but thinking weep holes will likely cover that ok.