1. DOMESTIC DRAINAGE SYSTEM 2012BC25444

2. INTRODUCTION Drainage is a system of pipe work underground to convey the discharge from sanitary fitting and drain pipe to a suitable disposal installation.

3. TYPE OF DRAINAGE There are two types of drainage These are [a] Surface water drainage [b] Foul water drainage

4. SURFACE WATER DRAINAGE Surface water within the building are open paved yard may be discharged with gullies dug in permeable ground and may also convey to sewer through surface water drain.

5. FOUL WATER DRAINAGE Foul water is classified into:- [i] Waste water- this the discharge from the kitchen, sink, bath and wash hand basin [ii] Soil waste-discharge from waste water from closet and urinals. Foul water can be conveyed out of the building by use of :- [i] one pipe system [ii] two pipe system [iii] single stack system.

6. REQUIREMENT FOR SINGLE STACK SYSTEM Sanitary fittings must be grouped closely to the main pipe so that the branch is short as possible. Bath, basin and sink must be connected separately to the main stack. Waste pipe must have a fall gradient of between 1/48 and 1/12. This reduce the possibility of self siphonage of the seal trap.