First slab with the fiber mix done, here's how it went

I've been running fiber mix on my last three pours, a 10x20 patio and a couple walkways, and the fuzz phase still catches me off guard every time. What helped me was misting the surface lightly with water from a pump sprayer before I started finishing. The fibers lay down way easier when the top is damp instead of dragging a trowel over dry hairy concrete and pulling little tufts out all over the place. One thing I learned the hard way on the first patio: don't wait as long as you would with regular mix to start troweling. The fibers seem to grab the surface a bit sooner and if you get on it too late you fight it the whole afternoon. My wife's uncle who did concrete for thirty years told me the fiber stuff finishes faster, and he was right.

I also kept my joints and I'm glad I did. The walkway I poured in fall of 2022 has cracked exactly on the saw line and nowhere else, which is all you can ask. The one section I got lazy on and spaced the joint a little wide shows a hairline crack between the cuts, nothing serious but it's there.

Freeze thaw hasn't bothered mine up here in Michigan but mine all got air entrained mix, so ask your yard if they're putting air in it for exterior slabs.

I ran a fiber mix last fall on a 10x12 pad for my generator and learned the hard way that it behaves differently in the truck. The stuff stiffens up fast. Mine got really tight and grabby about 20 minutes off the chute, and the temptation is to have the driver add water to loosen it back up. Don't. Every contractor I talked to after the fact said that's the fastest way to trash the strength. If the mix arrives stiff, ask the plant to send it with a water reducer next time instead of doctoring it on site. On the freeze and thaw question, what I was told matters most up here in Wisconsin is whether the mix was air entrained, not whether it has fibers in it. The fibers do their job on the plastic shrinkage cracks while it cures, but the little air bubbles are what give the surface a chance against winter. My redi-mix yard asks if you want air in the mix when you order, so it's worth asking yours before the next pour.

So far the generator pad has come through one winter fine, just the usual hairline check here and there. I still sawed joints in it same as always, no shortcuts there either.

This thread is making me feel better about a pad I have to pour next month. My worry is down the road, like ten years from now when the surface wears down from foot traffic. Does the fuzzy stuff ever start showing up again on old fiber concrete? My neighbor has some old steps that look kind of hairy in spots and I always assumed it was a diffrent material, but now I wonder if it was fibers coming back through the worn spots.

For anything outside I've gone the other way on finishing too. Did a 24x24 garage apron last spring with fiber and skipped the steel trowel entirely, just hit it with a broom. The drag knocks most of the hairs down and tucks the rest under, so no fuzz and no torch pass needed. Steel troweled slabs get slick when wet anyway, and a rougher surface is safer underfoot in the winter. The yard charged me about 9 bucks a yard over their standard mix for the fiber, which was cheaper than what I was spending on wire and the time fighting it flat.