Concrete Services in Johnston, Iowa — Engineered for Iowa winters

How do Johnston's wooded hills shape a walk, a patio or a wall?

Under the trees, the ground is Des Moines Lobe glacial till, a clay-heavy soil the last glacier left. Building codes here put frost depth at 42 inches, and this kind of clay heaves as it freezes and drops back in the thaw, so how the ground is prepared decides how long the concrete on top stays flat.

Johnston has grown mostly since the 1980s, with many custom-built homes on large lots. On those lots JLB forms curved and wrap-around walks that follow the grade and the trees, and cuts the control joints to the layout so the walk cracks along those lines instead of across the arc. A standard patio is four inches of concrete over a prepared base, made thicker and tied with steel under an outdoor kitchen, a fire feature or a hot tub. A retaining wall is a structure, so it's poured as one continuous rebar-reinforced piece, with its footing below the 42-inch frost line.

What are your options once Johnston marks your sidewalk?

Johnston's sidewalk program divides the city into eight zones and inspects one each year, using city staff or a contracted firm, and a complaint brings an inspection of its own. If squares in front of your home get marked, the notification letter sets the deadline, and the city gives you three ways to meet it.

• Do the work yourself. You'll need a city construction permit, which has no fee, and the forms and grade have to be inspected, booked at least 24 hours ahead. Once the old sidewalk comes out, the repair must be finished within two weeks.
• Hire a qualified contractor. The same permit, inspections and two-week rule apply, and the price is whatever you agree with the contractor. JLB is one of those options: our own crew pours broom-finished walks on a compacted base, start to finish.
• Use the city's contract. The city bids a sidewalk contract each year and puts its anticipated cost at $400 to $600 per panel. You can pay that directly or have it included in a special assessment on the property.

Whichever way you go, the city says it has no funds to offset the cost.

Which fixes does Johnston accept for each type of marked square?

The inspection sheet gives every marked square a repair type, and the type decides what the city will accept:

• Types B, D and F must be removed and replaced, and the city recommends doweling the new squares (pinning them with steel bars) to the squares beside them.
• Types A and C may be replaced or mud-jacked, which means pumping material under the square to raise it, with mud-jacking not to exceed 5%.
• Type A may instead be beveled with a grinder, if it doesn't exceed ½ inch.
• Type E may be sealed with a rigid sealant once the vegetation and debris are cleared out.