Concrete work in Dover
William Penn proposed a court town called Dover for Kent County in 1683, though its streets, squares and lots weren't laid out until 1717. More than three centuries later, the town's driveways, walks, patios, garage floors and shed pads are still made the same basic way: a prepared base, the right mix, reinforcement, joints and a careful cure. A slab that skips any of those steps usually shows it within a few winters.
Local weather, measured in town
Dover has a NOAA engineering weather station at Dover Air Force Base, so the figures here describe local conditions:
- a 100-year rainfall rate of 3.0 inches per hour;
- about 51 freeze-thaw cycles in an average year;
- a 99% winter design temperature of 17°F;
- a 1% summer design temperature of 89°F.
Each of those numbers points at a different part of the job: drainage, freeze-thaw durability, winter pours and summer curing.
Water decides how long a slab lasts
A downpour of 3 inches an hour has to go somewhere. Water that runs toward the house soaks the soil against the foundation, and water that sits under a slab softens the base and lets it settle. Ask each contractor:
- which way the slab will slope, and by how much per foot;
- where the runoff from the slab ends up;
- whether downspouts need extending or piping under or around the new concrete;
- how the edges will meet the lawn and beds so water drains off rather than pooling;
- whether the soil on your lot needs extra base material or drainage to stay firm.
Freeze-thaw and deicers
About 51 freeze-thaw cycles a year means water gets into the surface, freezes, expands and thaws again and again. That's how concrete scales and pops. Ask:
- whether exterior concrete will be air-entrained, and what strength mix they'll use;
- how they'll finish the surface; overworking the top layer weakens it;
- when a sealer should go on, and how often it should be renewed;
- which deicers they'd keep off the slab, especially in its first winter.
Hot days and cold days
On an 89°F summer afternoon, fresh concrete can lose water too fast and crack or dust. In winter, a slab poured before a hard freeze can be damaged before it gains strength. Ask how the contractor cures concrete in heat (curing compound, wet curing or covers) and what they do, or refuse to do, when a freeze is in the forecast.
Base, reinforcement and joints
Ask what will be dug out, what base goes in, how deep it is and how it will be compacted. Ask the slab thickness for each area, since a driveway that carries a truck needs more than a garden path, and whether it will be reinforced with wire mesh, rebar or fibers. Ask where control joints go and how deep they'll be cut. Joints decide where concrete cracks; they don't stop it from cracking.
Checking the company
Delaware law requires construction service businesses to register with the Office of Contractor Registration at the Delaware Department of Labor before beginning work in the state, in addition to registering with the Division of Revenue, and the department publishes a lookup of registered contractors. The Division of Revenue also requires any contractor doing business in Delaware to hold a business license.
Those checks show the company is set up to do business in the state. They don't show how well it pours a slab, so ask for addresses of recent driveways or patios you can look at.
Comparing quotes
Get each price in writing and compare:
- area, thickness and finish for each section;
- demolition and removal of old concrete;
- excavation, base material and compaction;
- reinforcement and joint layout;
- slope, drainage and any downspout work;
- the curing method and any sealer;
- the warranty and what it excludes.