Brick gutters should be laid on a four-inch concrete base and firmed with bar sand or a cement grouting. A concave brick gutter, eighteen inches wide, should slope three inches to the center. If a curb is desired the brick should be laid on end with the gutter finishing against it, and sloping two to three inches to the curb.
The most pleasing gutters are those of turf. Such gutters should be concave, with a slope toward the center of from one to two inches to the foot. A gutter four feet wide should slope two inches to the center. A gutter six feet wide should slope one inch to the foot, giving a three inch depression as the minimum. The carrying capacity is increased by the increased breadth. Where the area to be drained is large the gutter may have a maximum dip of six inches. After sodding the gutter a light coating of soil should be spread over the surface and sown with a good quality of grass seed.
In sod gutters inlets are necessary to carry off the surface water. The number required will be governed by the area to be drained. In rolling ground with large areas it is usually necessary to place them every fifty feet. When building a driveway where sod gutters have been adopted the drive surface should be finished even with the soil so that the water will run off into the gutters.
Turf gutters should be formed of tough sod cut from an old pasture. Before laying the sod, the concave surface should be covered with three or four inches of good soil and made true and even with a template. This can easily be pulled along as the soil is deposited and a uniform surface made for the reception of the sod.
Every Spring the edge of the gutter should be tamped down along the edge of the drive, as the frost will heave it higher than the road metal. It should be rolled when the lawn is gone over in early Spring after the frost is out of the ground.
Catch basins (Fig. 56) may be constructed of concrete or brick, whichever material is more convenient to the operation. The concrete construction is simple and should consist of a mixture of one part Portland cement, three parts of sand, and four parts of crushed stone. Side walls should be six inches thick plumb, and an opening left for the outlet pipe one foot above the bottom of the basin. This will allow a space for the sand and debris to collect.
The side walls for brick catch basins should be at least nine inches thick, built of straight, hard, building bricks that will ring clear when hit together. They should be laid in a Portland cement mortar consisting of one part cement to two parts of sharp sand.
Fig. 63. - A good type of catch basin grating.
Fig. 64. - A catch basin designed to receive a large volume of water.