replying to HotRdd, MDCraft General Contractor wrote:
So sorry to disagree with you statement concerning the mesh, wire or
fiberglass. It does NOT keep it from cracking. It keeps it from falling
lower, creating a trip hazard between the two pieces where the crack has
occurred. "Concrete is guaranteed to crack", That's on my contracts and I see
on new contracts as well. The closest additive that keeps it together better
and resist cracking would be the fiberglass since it is throughout the
concrete mix before it's poured out into the area desired.
The so called "cuts" during the pour are not "cuts" but trailed in control
joints. Meaning, hopefully when the concrete cracks it will crack at the
weakest place. Since the control joints are basically thinner concrete, it's
allowing the crack to run inside the control joint and not be as noticeable.
A "cut" joint can only be used when the concrete has dried enough for the
blade to saw the concrete and rock inside the concrete and leave a nice clean
edge. It's also used on concrete that is walked often or used with items
moved across the floor. It's a smoother transition rather than a trialed in
control joint, because it's smaller.
Lastly the additional concrete thickness does change the forming expense, why
you ask. A typical 2x4 is only 3.5" wide therefore the contractor has to use
2x6 which is 5.5" wide to handle the additional concrete depth as well as the
pressure applied to the formed walls, as the thicker concrete is heavier or
stronger side load.

--
for full context, visit https://www.homeownershub.com/constr...not-21562-.htm