Some concrete ideas
From code issues to color choices, there are a lot of things to keep in mind when your sidewalk or driveway needs replacing.
Our poor mothers: Growing up on the sidewalks of New Orleans, kids were always mindful of the danger that a playmate might cry out, “Step on a crack; break ya mama’s back!” This would stop kids in mid-romp and force them to tiptoe gingerly around the curse. The terrible state of the sidewalks often made it a great challenge.
To this day, walking the sidewalks of New Orleans, I occasionally hear that Yatty exhortation in my mind. And when I do, of course, I try not to step on the cracks.
That was the extent of my childhood involvement with concrete. Patrick Gurley’s childhood was much more about sidewalk cracks than mine. He grew up watching his dad and uncles break and pour concrete. Today, he runs the 45-year-old family business, Gurley’s Concrete.
There’s plenty of room for him to apply his experience in contemporary New Orleans. The sinking, crumbling old sidewalks we grew up with have gotten even worse with time. But more than just the ravages of time have affected the city’s concrete. With every big rebuilding job in town, sidewalks and driveways tend to bear the brunt of construction. About 10 years ago, a roofing company had to buy me a new sidewalk after it parked heavy equipment in front of my house to deliver plywood and shingles to my neighbor’s roof. That damage occurred in just one day. Imagine the damage from earthmovers and delivery trucks on a long-term job site.
Then there’s the simple need for upgrades. If you’ve poured $100,000 into rebuilding your house to spanking-new condition, it just makes starker the contrast with a ratty-looking old sidewalk or driveway. On the other hand, with all the colors and patterns you can lay on concrete, they can go from being merely functional amenities to providing aesthetic enrichment. Gurley says there are more than a dozen color options, ranging from terra cotta to buckskin. Stamp patterns include slate, cobblestone, flagstone and old Chicago brick. “Nowadays, you just have so much to choose from,” Gurley says.
Of course, there’s a right way of doing it. First of all, there are code issues. Although a lot of sidewalks in historic neighborhoods are only 3 feet wide, that’s not up to code. You can lay a 3-foot sidewalk only if you’re replacing an existing sidewalk. In Jefferson and Orleans parishes and elsewhere, a 4-foot width is standard for a new residential sidewalk. Legal issues also pertain to driveways –– such as whether you’re allowed to cut the curb for a driveway at all.
Then there’s the matter of drainage from your property to the street. When designing a driveway from a garage, for example, the downward slope should run at least a quarter-inch per foot but perhaps more. Sidewalks shouldn’t have much more than a quarter-inch-per-foot fall (an inch across 4 feet) away from the house. It should give “a very slight fall,” Gurley says,” because you don’t want your sidewalk cocked up on an angle.”
Concrete contains a mixture of cement, aggregates, water and other materials, and its strength depends on the mixture. It gets rated according to how much weight it can support, on a basis of pounds per square inch, or PSI. It can range up to 5,000 PSI for, say, heavy industrial or public works projects. For residential work, concrete workers typically use a lesser grade. Gurley says that 3,500 PSI should do the trick for driveways, sidewalks and patios. Although some recommend 4,000 PSI, Gurley says that may be overkill. The thing to keep in mind is that the stronger the concrete, the greater the cost.
Once you determine the raw materials, there’s prep work to be done. To get the ground ready, the dirt needs packing. Gurley typically packs the dirt down 2 to 3 inches and then brings in more dirt and packs some more. “You pack it until you have a good, tight, strong base,” he says.
After the project area gets framed in, the contractor should insert a bed of heavy wire; this will help to hold the concrete together, even when it cracks. Because concrete shifts and expands, expansion joists should go in every 8 to 10 feet.
The concrete should be poured 4 inches deep for a sidewalk and closer to 5 inches deep for a driveway.
If you’re going with colors, Gurley strongly recommends having the color mixed in with the wet concrete. Some people let the cement dry and put color on top afterward. He says that’s a mistake because when it chips and cracks, the underlying gray starts to show: “Once you drive on that a year’s time, it looks like crap.”
Coloring and stamping can look elegant but cost about twice as much as a plain concrete job. That’s because the color costs more, the stamping requires more hours of work and it all requires extra cleaning and sealing, Gurley says.
Also, when you get a new sidewalk, spray it down every day for several days, particularly during warm months. Keeping the sidewalk wet during the curing process helps the concrete to dry more slowly, meaning fewer cracks and longer life.
Even the best concrete job won’t last forever. Gurley jokes that he can make customers three guarantees about a new sidewalk: “It’s going to get hard, it’s going to crack, and nobody’s going to steal it.”
But at least in the years until it cracks, you won’t have to watch “ya mama’s” back.