Centennial Walkway Contractors

Park at the curb and look down the walk before you get out of the car. Low sun helps. What you want is shadow: a hard dark line where one panel rides above the next, a wider band where the run has tipped toward the lawn, a dull patch that stays damp a day longer than the concrete around it. Those three shadows account for most of the walk work we do here.

Centennial's older sections give us plenty of practice. Homestead, Foxridge, and Southglenn are full of paths poured when the houses went up, over whatever dirt was handy, and four decades of winters have had their say. Runs out around Piney Creek fail differently, usually at a joint somebody rushed on build day. Either way the diagnosis starts from the street, not on your knees with a level.

Three shadows and what each one costs you

The first shadow is a hard edge. One panel came up, or its neighbor went down, and now a vertical lip crosses the path. Frost got under it, a root grew beneath it, or the ground below simply left. That does not heal. The second shadow is softer, a whole section leaning, and you notice it because the joint lines quit running parallel to the house. The third barely reads as anything: a patch that dries slower, a green film in October, a rim of silt where water stood and then went away.

Ranked by how fast they turn into a real problem, the lip wins going away. A quarter inch is enough to catch a toe, and people carrying groceries do not look down. The lean is slower and worse in the end, because a walk tipped the wrong way delivers every gallon of melt straight at your foundation wall.

Where a walk meets something else

The lawn side, the house side, and where the water ends up

A walk should shed water sideways, about a quarter inch of fall for every foot of width, and it should shed it away from the house. Get that backward and you have built a shallow trough that funnels roof runoff and irrigation overspray to the base of your foundation, every storm, for thirty years.

Narrow flatwork suffers more than wide flatwork here, and the reason is geometry. A driveway is a big mass that shares load across its width. A forty-inch ribbon has no such luxury, so when moisture collects along one edge and freezes, the ribbon answers for it alone. Add a roof drip line with no gutter above it and you get one panel spalling while the rest look new. Pouring new concrete into the same wet spot just buys you a fresh slab to ruin. Deicer finishes the job: magnesium chloride drives water into the top layer and pops it off in scales. Sand gives traction and does nothing to the concrete.

Picking a week for narrow flatwork

May through October is the easy answer, and late September has a lot going for it inside that window. Dry ground, no afternoon storms stacking up over the foothills, and air that stops pulling water out of the surface faster than we can finish it. Early spring is trickier than people expect, since soil at 5,833 feet holds winter moisture well into April and a soft subgrade compacts poorly no matter how many passes we make.

Cold work is doable. Warm the mix water, dose it with a non-chloride accelerator, keep insulation down for the better part of a week. What we refuse to do is place over frozen ground, because the moment it thaws the slab drops into the space it left. Walks are small and fast, so lead times run shorter than on almost anything else we pour.

Nine times out of ten the customer points at the crack and we end up looking at the downspout twenty feet away. Concrete does what the water under it lets it do.Straight from the crew