ABSTRACT
Drainage is the above and below ground services to remove effluent from a building. To provide a drainage system which is simple, efficient and economical by laying the drains to a gradient that will render them self-cleansing by gravity and will convey the effluent to a sewer without danger to health or giving nuisance. Provision is required for maintenance and inspection of drainage systems. Constructed from brick, precast concrete or plastic, these provide a means of access to drainage systems where the depth to invert level does not exceed 1m. A roof must be designed with a suitable gradient/fall towards the surface water collection channel or gutter, which, in turn, is connected to vertical rainwater pipes that convey the collected discharge to the drainage system. Road drainage consists of laying the paved area or road to a suitable cross fall or gradient to direct the run-off of surface water towards the drainage channel or gutter.
