hey everybody. i am looking to add 2 footings in a crawlspace under my 2bedroom ranch in staten island, new york city. it was built in 1935 and there is a slab in the crawl space but it just looks like they just poured the concrete in there and did not smooth it out, real rough looking. i don't know how thick it is but the home owner before me did post a bunch of 4x4's from the slab to the beams and i dont see any cracking or the post penetrating the slab.... anyway my question is do i have to chop out a hole about 24''x24'', 12'' deep, add an inch or so of gravel, re-bar, form it and pour concrete...or.... can i do the above without chopping into the slab, just building the form on top of the slab..... or... can i drill some re-bar into the slab, put some cement down, put three blocks on the slab so the re-bar is thru the holes of the cinder blocks and fill them cement ??? any how thanx in advance for the advice. i am sure you guys probably have a better idea..