Precast Cement Posts at www.japanese-home-gardens.com

FENCES MUST have stout posts, and if these are of wood they should be at least 3in square for low fences and 4in square for tall ones. Precast cement posts are also available, some with slots to accept ready-made Fence panels, and both these types should be set into the ground by at least 2ft. Otherwise, use Fence spikes. These come in various sizes and support the posts.

Reinforced-concrete conduits may be monolithic, precast, or prestressed. Precast pipe is made in sizes up to 180 inches. Steel cylinder pipe is recommended where the head exceeds 100 feet. Prestressed concrete steel cylinder pipe is available in sizes 24 to 144 inches; it requires a better grade of steel, but only 70 to 80 percent of the amount needed in non-prestressed pipe; concrete is of better quality, and Wall thickness can be reduced. The hydraulic carrying capacity of concrete, asbestos cement, or cement-lined metal pipes does not deteriorate as rapidly as in tar-coated metal pipe; however, slimes will build up in such pipes and reduce the carrying capacity.

PIERCED CEMENT blocks come in a range of geometric patterns (right). They are particularly suitable for screening patios to allow cooling breezes and light to Filter through, but they can also be built as a low wall, either on their own or on top of a low brick wall, around a patio, or to divide the garden. Because the cast-in patterns of the blocks are designed to make larger patterns, they cannot be laid in an interlocking bond. Instead, use a "stack" bond, that is to say, one laid on top of the other. To ensure a strong structure, insert a vertical pier every 1 Oft. These are constructed from hollow precast cement blocks which have slots in their sides to accept the ends of the blocks. The blocks must also be carefully aligned, otherwise the overall pattern will be affected.