Like the rooms of a house, landscapes have floors (floorscapes of lawn, ground cover, structural materials), walls (wallscapes of vegetation, screens, masonry), ceilings (skyscapes of overhanging trees, arbors, sky). The man-made or natural enclosures must be integrated with the design pattern created for the area.
The enclosures of outdoor space help to establish the lines of a design pattern. Enclosures may also be used to provide partial or complete vistas, or to conceal objectionable views. Enclosures help to promote privacy, prevent or direct movements either of people or of domestic animals, reduce sounds and winds, and lessen the glare of the sun. The careful selection and arrangement of enclosures is of fundamental importance in landscape design.
Requirements of Floor Enclosures
The living materials that can be used on the floor, or the earth spaces, of a landscape have already been discussed in connection with plants and lawns. There are structural earth-floor surfaces that are available for use. Structural earth-floor surfaces have to meet such a variety of specifications that they can never completely measure up to them. For example, they should have the right texture. In many cases, they must be smooth enough to permit dancing, and yet rugged enough for games. They should combine well with other surfaces, not only in the landscape but also in the house itself. Furthermore, they must be dry and clean, durable, not too costly, and not to hard to construct. No one surface can be expected to fill all of these requirements.
The following observations apply to a few of the structural kinds, as distinguished from the living kinds, that you may use.
Bark, Gravel, and Crushed Rock
Bark, especially the bark of oak, cut into small pieces, makes an attractive and comfortable earth-floor surface. One drawback of bark is that it scatters unless it is confined between headers. It is useful on paths and under apparatus in a playground. The practice is to place this material over a 2 to 3 inches gravel or sand foundation.
Gravel makes a clean and durable surface. It is, however, rather uncomfortable underfoot, and weeds tend to grow through both gravel and crushed stone. Gravel is also apt to get kicked or rolled out of place, onto grass or other pavements.
Soil, Cement, and Asphalt
Cement and garden soil mixed together produce a hard, dry surface, which is not, however, as strong as concrete. Asphalt, if properly installed, produces a surface almost as tough as brick concrete, and is one that can be quickly installed. A disadvantage of asphalt is its heat-retaining qualities and its unattractive appearance. Some varieties are suitable for use on a patio or terrace, but an improper mixture of asphalt can retain prints and tracks and exude tar on hot days.
Brick, Tile, and Flagstone
Brick makes a slid, durable surface, with warm colors and pleasant contrasts. The units are small in scale, which makes them suitable for domestic use. Brick may be laid in sand, but for greater permanence should be set in mortar over concrete. All sorts or paving patterns are possible with brick.
Different kinds of tile may also be used as a surfacing; they are laid in sand or mortar, or over concrete.
Flagstones provide an excellent surface. Flagstones come in subdued colors, and in irregular shapes and thicknesses. You should select them with discrimination. If the soil is well drained, you need no other foundation than the earth itself. Otherwise, there must be a 2 inches foundation of sand or a concrete-slab foundation.
Concrete and Pebble Mosaic
Concrete gives a hard finish in a variety of surface treatments. The surface may be smooth, it may be brushed with a push broom finish, or it may have the aggregates exposed. Moreover, concrete can be treated for different color effects. Simple or elaborate mosaic surfaces may be produced with pebbles placed in mortar.