The key to slabs, foundations block joints and so on cracking or not has to do with the settling that does or doesn't take place. The better compacted and more stable the soil, the less settling and subsequently the less cracking. Moisture control thru proper drainage allows the ground to stay dry which reduces movement. Now of course fibermesh isn't applicable in all circumstances but.....One idea behind fibermesh was to eliminate the need for wire in slabs. Wire degrades, oh maybe not enough to really make a difference, but it does none the less. The amount of fiber needed in any given size slab is far less expensive than wire and more cost effectively introduced into the process. You only need one man to put in the fiber for that slab but many men to lay the wire. From a production construction prospective it makes sense and cents. That was the primary thing to drive fibermesh. As with any concrete element, moisture content and proper curing, can also play a role in whether or not cracking will occur. In the well over 100 houses I've built in my time, The only thing I didn't care for about fibermesh is it finishes fuzzy. The little fibers are like little hairs and if your flatwork crew isn't careful....Fuzzy wuzzy is your floor.
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