Such driveways may lead to the garage or up to the porch of the house. One of the cheapest types to the garage is a double runway for the wheels of the automobile. These runways should be about 4 feet 8 inches on centres and made 18 inches wide. They should be constructed in the same way that walks are built.
Where a full-width concrete driveway is built, it should be made about 6 inches thick at the centre and 5 inches at the edges, sloping from the centre out. At intervals of every 25 feet expansion joints should be built as was specified for walks.
Concrete Runways to Garage.
The only difficult problem in the construction of concrete steps is the making of forms. These should be well braced to prevent bulging when the concrete is tamped into them. The aggregate ought not to be over 3/4 inch diameter, so that as the material is tamped into the forms and the sides spaded, a good surface will be left when the forms are removed. If the aggregate is too large, some pieces may catch along the forms, and when they are removed large holes will be found in the risers of the steps. The treads should be finished with a wood trowel.
Concrete Garden Retaining Wall.