Rebar Installation

Concrete is enormously strong in compression and weak in tension. Steel is the opposite. Reinforcement is what lets the two work together — and it only works if the steel is the right size, in the right place, at the right depth, properly lapped and properly tied. We provide rebar layout, fabrication, placement and tying for slabs, footings, walls, columns, piers and structural concrete throughout Charlotte and Gaston County.

Concrete cover is the distance between the steel and the nearest concrete surface, and it is the single most important variable in how long a reinforced structure lasts. Too little cover and moisture, chlorides and oxygen reach the steel. The steel corrodes. Rust occupies several times the volume of the original metal, and that expansion cracks the concrete outward from the inside — the spalling you see on old bridge decks and parking structures.

Typical requirements are around three inches for concrete cast against earth, two inches for formed surfaces exposed to weather, and less for interior conditions. Those numbers are not suggestions. We hit them using proper chairs and spacers rather than bricks, stones or whatever is lying around the site, which is how cover quietly disappears on a lot of jobs.

There is a widespread shortcut where wire mesh or rebar is laid directly on the sub-grade and then pulled upward with a hook as the concrete is placed. It is fast and it looks like it works.

It does not. The steel ends up at an inconsistent and unverifiable depth, frequently near the bottom of the slab where it contributes almost nothing to controlling surface cracking. Reinforcement in a slab generally needs to sit in the upper third to do its job. We support steel on chairs at the correct height so it stays exactly where the design put it, before, during and after the pour.

Rebar transfers force between bars through lap splices — an overlap long enough for the bond with the surrounding concrete to develop the bar's full strength. Lap length depends on bar size, concrete strength and bar position, and it is commonly in the range of 30 to 40 bar diameters. Short-lapping is invisible once concrete is poured and it creates a hinge point exactly where continuity was needed.

We lap to the specified length, stagger splices so they do not all land in the same plane, and tie intersections properly. Ties are not structural in themselves — their job is to hold the mat in position against the considerable force of concrete being placed against it. A mat that shifts during a pour is a mat that is no longer where the engineer put it.

Welded wire mesh is fine for light residential flatwork where the only goal is holding shrinkage cracks tight. It is thin, it is cheap, and it is easy to install badly.

Rebar is the right choice anywhere there is real structural demand — footings, walls, columns, piers, driveways carrying vehicle loads, commercial flatwork, and any slab where differential settlement is a genuine risk. It is heavier, it costs more to place, and it gives you a slab that behaves predictably when it is loaded. If your plans call for one and a contractor quotes the other, that difference is worth asking about.