Are Synthetic Fibers An Alternative for Welded Wire Mesh Sheets?

The usage of welded wire mesh sheets has decreased in certain areas of the industry such as slabs used in residential installations. Synthetic fibers or fiber mesh has been marketed and sold as a substitute to welded wire mesh sheets to take over as the staple of many construction projects. Many contractors express their distaste for welded wire mesh sheets due to them just being a hassle to work with. Synthetic fibers are branded as a more ready-to-go solution that doesn’t require bundles upon bundles for residential slabs. Is this true and are there any pitfalls to switching?

Welded Wire Mesh Sheets & Synthetic Fibers: A Comparison

If you follow manufacturer recommendations and warnings, synthetic fibers don’t necessarily provide the same solution as welded wire mesh sheets. Welded wire mesh sheets were used extensively due to their ability to hold together slabs even after the soil settles. This duty allows for minimal cracking and high durability for the slabs. Synthetic fibers inherently don’t provide the same benefit. Synthetic fibers help hold together slabs but kind of shut down in terms of benefits after the initial twenty-four hours. 

Synthetic fibers provide most of their benefit before the concrete is hardened into a slab. Synthetic fibers reduce plastic shrinkage as the concrete goes from a liquid to a solid. Plastic shrinkage isn’t always a worry. Plastic shrinkage occurs when weather conditions make concrete prone to drying quicker than it is supposed to. This benefit shows that welded wire mesh sheets are a lot better for the long term whereas synthetic fibers are better for the initial pour and under certain environmental conditions. 

With this being said, why are synthetic fibers being marketed in such a way that they are here to end welded wire mesh sheets? Well, the key here is that they are specifically targeting only residential slabs and nothing above that. Residential structures don’t require much reinforcement. If soil conditions are suitable, synthetic fibers can be utilized and perform the exact same as welded wire mesh sheets. If you want to control plastic shrinkage, you would utilize synthetic fibers. If you want to control cracking after the hardened concrete, you would use welded wire mesh sheets. If a residential slab needs strong reinforcement, then neither is an option. That is where you turn to rebar for your installation.  

What Are Some Synthetic Fiber Options And Their Proper Dosages?     

The most commonly used option for synthetic fiber is polypropylene. Other available options are nylon and polyolefin. Polypropylene comes in two different variations. The first variation is fibrillated which are shredded to form a net that is tighter with cement paste but is prone to protruding from the slab. The other variation is monofilament. Monofilaments are not as good in terms of binding to the concrete but don’t run the risk of protruding. Dosage levels vary depending on who you ask. Contractors recommend over the manufacturer's dosage due to improved properties in terms of plastic shrinkage, impact resistance, and more. Manufacturers' recommendations are more in line with the branding rather than optimal performance. Manufacturers recommend a lower dosage to allow synthetic fibers to be able to compete with welded wire mesh sheets. 

I hope this helps!