Reply to "Ask the Builder" question

I am a concrete contractor in Tampa FL.  I  operate commercially as Velocity Construction. Before having these businesses I worked commercially for 23 years on high-rise and super flat concrete construction. I give these qualifications, to lend weight to my comments. In the article you refer to a rebar mat and 4500 PSI concrete. I feel this is an unecessary expense for the homeowner, and have been pouring 3000PSI concrete with fiber for years on my own with no cracking. I think that this whole cracking issue is in fact a misnomer, as concrete has to crack being a rock like substance, and joints therefore should be referred to by there true name which is control joints. By "controlling" the cracking by joint placement, the ugly joints resultant from uncontrolled cracking is replaced by straight attractive joints. This cracking issue is addressed in Concrete Construction Magazine in the July issue and in fact they have a competition for joint placement. Proper ground preperation and the proper "slump" meaning stiff but workable concrete I feel are a more important discussion than the use of expensive materials. A rebar mat is completely unecessary- are you going to land your helicopter on it? 5 inches of concrete is also unecessary- 4 inches is what all residential plans call for! Again 4500 PSI concrete is an unecessary expense. You have to realize that the average homeowner is looking for an affordable solution- not building the pyramids! What if they decide down the road that they want to change their back yard. Do you realize how incredibly difficult it would be to demo concrete with a rebar mat? That is something typically used in bridge construction


. Of course your recommendations will result in a stronger slab, but the resultant hundreds if not thousands of extra dollars of labor and material will not justify the extra strength. Over-building nearly always results in problems down the road.