At the point where the drive intersects the highway it is advisable to pave the surface from the outside edge of the gutter to the property line (Fig. 59). It is necessary, usually, to increase the drive incline at this point to meet the gutter grade, and if macadam is used there is constant erosion. The paved surface prevents this and affords a hard surface for pedestrians. Such an approach should be constructed of cement or brick. If cement is used the surface should be roughened to prevent slipping.
GUTTER CONSTRUCTION Fig. 60. - A pleasing and serviceable drive defined by a gutter constructed of Belgian blocks. - See page 61.
Where the walk or drive grade is not steep gutters will not be required and a few catch basins will take care of the surface water (Fig. 60). If the surface over which the water gathers is great enough the road will be more pleasing and serviceable when defined by a curb or gutter.
Fig. 61. - Section of a concrete gutter and curb. - See page 59.
Fig. 62. - A section showing the construction of a rubblestone gutter and curb.
Where gutters (Fig. 61) are required the most satisfactory, although undoubtedly artificial in appearance, is the cement curb and gutter combined. This forms a good, substantial feature against which to finish the sod on one side and the road metal on the other. The foundation on heavy soils should be extended to a depth of eighteen inches.
Use clean boilerhouse cinders or stone spawls as a foundation to within five inches of the finished grade; on this place the concrete, consisting of a mixture of one part Portland cement to four parts of sand and five parts of crushed stone. The finish coat should consist of one part Portland cement and two parts of sharp sand, troweled even and hard.
The rubble curb and gutter (Fig. 62), built of quarried or field stone laid on edge and swept with chips, is very suitable for suburban and country districts. Such gutters should be not less than eighteen inches wide.
An objectionable feature of the rubble gutter is that the grass and weeds grow up through the interstices. Where the stone is laid on a good foundation of clean cinders, twelve or eighteen inches deep, the joints may be grouted with Portland cement mortar, using three parts sand and one part cement. This grouting will prevent the grass and weed growth.