That old timer at the supply house swore by fiber mesh in every slab

Harold from the yard told me to dump two pounds of fiber mesh into my residential driveway mix even though I was planning on wire mesh. I figured he knew his stuff so I did it, and now I got cracks spiderwebbing through the whole pour after three months. Did I mess up the mix ratios or is fiber mesh just not the right call for driveways in cold climates like Minnesota?

5 comments

5 Comments

murphy.aaron2mo ago

Did you happen to read that article from Concrete Construction magazine about fiber mesh vs. wire mesh in freeze-thaw zones? I remember seeing a test they did where fiber mesh actually worked fine but only if you kept the water down and used a low slump mix. Sounds like maybe your mix was too wet, which lets the fibers clump up and not do their job against temp changes. That spiderwebbing pattern you're describing is what they showed in the pictures for that exact mistake.

dakota4152mo ago

@murphy.aaron Yeah I remember that article, I think I dogeared the page and then lost the whole magazine in my truck for six months. Classic move on my part. The spiderwebbing is exactly what I'm seeing, so maybe I should've paid more attention to that low slump advice instead of just dumping in extra water to make it easier to work with. Guess I learned the hard way that fibers don't care about your schedule. Next time I'm gonna try actually following directions instead of thinking I know better.

seth_singh201mo ago

Ngl I used to be one of those guys who figured fiber mesh was basically just snake oil for slabs that weren't gonna see real action. Thought you needed wire or rebar to handle anything serious. But honestly reading through this thread and that old article you're talking about is making me rethink a lot of my old opinions. I've definitely been guilty of just dumping extra water in the mix to keep things moving and then wondering why the surface looked like a spiderweb after the first freeze. Gonna have to swallow my pride and try that low slump method next time, even if it means working a little harder on site.

milam482mo ago

You got a wet mix in a Minnesota winter and the fibers couldn't hold up against the frost heave, right? Next time keep it stiff and throw in some air entrainment, that combo handles the cold way better than just fiber alone.

thomas_torres1mo ago

Yeah I was reading up on this somewhere, they did testing up in Canada and the whole thing came down to keeping the water out of the mix. You can have the fanciest fibers money can buy but if your slump is over 4 inches they just float around and don't bond with anything. Sounds like your problem was more about the water than the fiber mesh itself.