Driveway project handbook

A concrete driveway project pours a slab that carries vehicle load, connects to an existing garage floor or foundation at one end and to a street apron at the other, drains water away from the house, and lasts twenty to forty years. The recorded holder's driveway work covers two builds — a residential 4-inch slab and a commercial or heavy-vehicle 6-inch slab — and includes both new installations and replacements of existing pads.

The build is not one number picked for a whole slab. It is a stack of choices: how thick, on what base, with what reinforcement, what mix, what jointing, what finish, what cure, what sealer. Each choice is recorded on the job sheet and is checked in the pour-day list before the truck is on the way.

The routine residential concrete driveway is a 4-inch thick slab on a 4-inch compacted aggregate base, reinforced with a #3 rebar mat, poured 3500 to 4000 psi mix with 3/4-inch aggregate, jointed on 8-to-12-foot centers cross-direction, broom finished, cured seven days, sealed at 28 days.

4-inch is the minimum for a passenger-car driveway. A drive that a work truck or trailer uses regularly, or that a delivery vehicle turns on, takes the 6-inch build.

The 6-inch build is used where the slab carries loaded work trucks, RVs, delivery vehicles, or where a commercial site has box-truck or bin traffic. The reinforcement steps up, the base steps up, the joint spacing widens and the mix goes to a higher PSI.

The jointing plan is drawn on the job sheet before the pour and cross-referenced to the installer playbook at /joint-planning/. Two joints, two jobs. Control joints handle shrinkage in the first weeks; expansion joints handle long-term thermal and moisture movement.

• Control joints — saw-cut in the 6–18 hour window after placement, to one quarter the slab depth. Spaced 8–12 feet on a 4-inch slab; 12–18 feet on a 6-inch. Cut cross-direction to the drive, in straight lines edge-to-edge.
• Expansion joints — full-depth, filled with a compressible material. Against the garage abutment, against the street apron, around bollards, light poles, drain grates and any support post in the middle of a slab. On a driveway longer than 50 feet, one expansion joint at approximately the midpoint.
• Aspect rule — no panel is more than 1.5 times as long as it is wide. A 12-foot-wide drive that is 30 feet long is cut into three 10×12 panels.

A driveway without drainage is a driveway with cracks. Drainage is set at the subgrade grade and again at the finish grade of the slab.

• Positive fall of 1/8″ per foot minimum away from the house.
• No ponded water on the pad on a wet-check day.
• Perimeter drain — French drain, trench drain or graded swale — where the pad sits below any surrounding hardscape.
• Downspout leaders extended off the pad footprint, not onto it.
• Trench drain across the driveway apron where the street elevation would otherwise drop water back onto the pad.
• Drain grates cast in on the same day as the pour, tied into the reinforcement, expansion-joint-isolated from the surrounding slab.

A driveway replacement is a specialized job. The old slab is demolished, hauled and disposed. The subgrade is re-checked and re-compacted — years under the old slab may have left soft spots or drainage lines that were not there originally. Any settlement at the garage abutment or the street apron is investigated before the new pad is poured.

• Demolition — one to two days depending on slab size; concrete hauled and recycled where the volume warrants.
• Subgrade re-work — replace any soft spots with #57 stone; re-compact.
• Doweled connection at the garage abutment — 12-inch smooth dowels drilled into the retained garage floor at 24-inch centers, greased at one end, cast into the new pad so the two slabs can move relative to each other without opening a step.
• Doweled connection at the street apron — depending on the apron condition; new apron poured against a dowel line where the old apron is retained.

A replacement is typically two to three weeks from demo to walk-through, plus the 28-day cure before heavy traffic.

Walk-through happens 7 to 14 days after pour once the cure window has opened enough for the client to walk the slab. The finished slab is checked against the contract, jointing is checked against the layout, drainage is checked against a hose test on request. The client leaves the walk-through with a maintenance sheet — cure window closed, sealer at 28 days, re-seal every 3–5 years, no de-icing salt in the first winter.

Warranty is one year on workmanship from the walk-through date. Material warranties on sealers and admixtures follow the manufacturer. Sub-surface issues that appear later — a leaking underground utility, a downspout re-routed by the client — are outside the workmanship warranty and are investigated case by case.