Arvada Mudjacking and Slab Lifting

Somebody is going to tell you that sunken walk has to come out. Sometimes that's right. On the older side of Arvada it usually isn't, because the concrete is still thick, still flat, and still strong. It just isn't where it used to be. Pumping a sand and cement slurry underneath puts it back, and the job is done before the afternoon is.

The pumping isn't the interesting part. The sorting is. We run slurry, we run polyurethane, and we run a saw and a skid steer, and picking wrong wastes money in a way you won't notice for two years. So most of this page is about how that choice gets made here, where a slab near Olde Town is a different animal from one out past Leyden Rock.

What the slab has to be able to take before we pump

Why a mud pump still earns its keep on the established blocks

The slurry is sand, portland cement, and water, mixed on site to whatever consistency the cavity underneath is asking for. It goes in through cores about the width of a quarter, a few gallons at a time, and fills the space with something close to the density of the dirt that used to be there. When a void is large and open, slurry is by far the cheapest way to put mass back under a slab.

The older parts of town keep producing that exact kind of void. Thirty years of downspout discharge landing beside a porch, a lawn graded the wrong way, an irrigation line weeping quietly for decades. Water carves a pocket, runoff enlarges it, and one wet April the slab drops into it. The concrete never failed. Something moved the ground out from under it.

We lift in small stages against a laser, checking the joint on both sides between shots. Overshooting a panel is worse than not lifting it, because coming back down is not an option.

Between the first drill bit and the last plug

• The water path gets walked first: downspouts, splash blocks, the low side of the yard, where the sprinklers land
• Laser grade shots to measure the real drop instead of the drop your eye reports
• Core layout chalked out, spaced to reach the whole cavity without weakening the panel
• Cores drilled, void probed for depth, slurry mixed to match what we find
• Slow pumping in stages, string line across the joint, nobody chasing the last eighth of an inch
• Cores packed with dry-pack, troweled flush, joints cleaned and left ready for sealant
• A written note on what caused the void, because a lift does not fix a downspout

Lift it, or pour a new one

Here's the honest comparison. A lift takes a few hours, no demolition, no haul-off, no cure, and you're walking on it that evening. A replacement means a week of hole where your driveway was, seven days before a car, twenty-eight before anything heavy. The price gap is wide enough that people assume a catch.

The catch is that a lift only buys back elevation. It does nothing for a scaling surface, nothing for a panel cracked into pieces, and nothing about whatever moved the soil. If your concrete has fifteen good years left and the only problem is elevation, lifting is the obvious call. If the surface is already sanding off under a broom and the joints have crumbled, you'd be paying to raise something you'll replace anyway.

The two-lift job is where we argue. Dropped once, pumped, dropped again, and we stop selling lifts. The ground is telling you something. Fix the drainage and pour new concrete on a proper base.

The pumping calendar at 5,344 feet

Slurry is cement, so it plays by cement rules. The ground and the slab both need to be above freezing while it sets, which puts the reliable season somewhere between March and late November. October and early November get busy, because people see the drop clearly once the leaves are down and want it handled before snow buries it.

Spring is the most honest month to pump. The soil is at its wettest, any cavity is fully open, and what you lift in April tends to stay lifted. We won't pump into standing water, though. Let a flooded void drain for two dry days first, or the slurry thins out right where support matters most.

Deep winter, we stop pumping mud and switch to polyurethane, which doesn't care what the thermometer says. On a freshly raised slab, treat the plugs like new concrete: shovel, sand, no magnesium chloride.