A concrete driveway is one of the largest single surfaces on a property, and it carries more weight than almost anything else you build outside. Most of what makes one last happens before the truck arrives: the ground has to be shaped, compacted and given a stable base so the slab is supported evenly from edge to edge.
What the work involves
A typical driveway job starts with removing the old surface, whether that is cracked concrete, asphalt or gravel. The crew then grades the area so water runs away from the garage and the house, compacts the soil, and adds a layer of crushed stone or road base. Forms are set to the final shape, and reinforcement is placed: steel rebar, welded wire mesh, fibers mixed into the concrete, or a combination.
Residential driveways are usually poured four to five inches thick. Areas that carry heavier vehicles, such as RVs, boats or work trucks, are often poured thicker. After the pour, the surface is finished, most often with a broom texture for grip, and control joints are cut or tooled in so that the cracks concrete naturally forms happen in straight lines where you expect them.
Questions worth asking
- How thick will the slab be, and what reinforcement will be used?
- What base material goes under it, and how deep?
- Where will the control joints be, and how far apart?
- How will water drain off the driveway and away from the house?
- Is removal and haul-off of the old driveway included in the price?
- Will the approach where the driveway meets the street need a permit?
Clear answers to these questions make quotes much easier to compare, because two prices that look far apart are often describing different amounts of work.
How long it takes
Removing an old driveway and preparing the base usually takes a day or two. The pour itself is often done in a single day. You can typically walk on new concrete within a day or two, but you should keep cars off for about a week, and heavier vehicles off for longer. Concrete keeps gaining strength for weeks, so a little patience at the start pays off over the life of the slab.
Signs it may be time to replace
Wide or spreading cracks, sections that have sunk or lifted, crumbling or flaking surfaces, and puddles that sit after every rain are all signs the slab or the base under it is failing. Some problems can be repaired; others mean the base needs to be rebuilt. A contractor who looks at the cause, not just the surface, can tell you which you are dealing with.