Last fall I had a contractor pour my front steps and a 8ft by 6ft side-walk. He also poured a patio for our walkout basement about 10 by 25 feet . I just noticed a few fine cracks in the patio. I was told he should have cut these with a saw in several places to stop this . Note that the concrete is that exposed brown pebbled look . I would like to rent a saw and saw these myself . How often should I cut the patio and how deep? I was going to run one cut end to end up the middle of long part and say one every 6 feet out from the house to the edge, about 1/2 to 3/4 inch deep . I do not know how wide the blade would be. For the side walk I was going to cut one from the steps up the centre . The steps and sidewalk run along the attached garage . In both cases the rebar is drilled and glued into the foundation .
aci recommends slab size to be 20 X inch thickness expressed as feet - eg, 4" thickness multiplied by 20 = 80 OR 8',,, generally speaking, a 10' x 25' would have 1 sawed ( or formed/grooved ) joint,,, w/o seeing the work done, can't say differently.
1 cannot stop conc from cracking however any cracking can be controlled by sawing/grooving/forming a proper jnt pattern.
IF you're certain ( i'm not ) your random cracks are not now performing as moving joints, we resolve this issue by sawing full depth,,, .125" blade's fine ( 1/8" ),,, again generally speaking, exterior conc is NEVER attached to structures !