Key Points in Restaurant Kitchen Drainage Design

Restaurant kitchens use the most water. If drainage clogs, odor and hygiene suffer. What should drainage design watch for? CHINENG explains below.

Restaurant kitchen drainage design notes

1. Odor, rodent, and insect control: cover open channels; use water seals; fit screened outlets and metal rodent guards with bars fine enough to block rodents.

2. Provide floor drains in pantries and cold rooms with brass or stainless covers; set a drain trough at the ice-machine front.

3. Channel depth is often limited by structure (about 300 mm in drop-slab zones); width follows flow. Prefer slope over 0.5% and length under about 10 m.

4. Drop the kitchen slab at least 30 cm for channels; add a catch basket before the main drain to filter solids.

5. Line channel sides with white tile or use stainless channels, with proper waterproofing.

6. Place stacks beside the largest drainage load without blocking work.

7. Provide grease separation: kitchen wastewater is oily and needs interceptors—preferably stainless—with baskets to catch large debris.

8. Use secondary centralized grease treatment before municipal discharge; appliance interceptors may sit on the floor or in the drop-slab space.

9. Keep branch drains short to the stack, or provide branch venting.

10. Heat-resistant plastic may be used in the drop-slab space; elsewhere prefer cast iron.

11. Open channels drain and clean easily but can smell; covered channels look neater and reduce odor but are harder to clean.

Kitchen waste piping

1. Avoid undersized equipment wastes; DN50 is common, DN75 is better. Direct floor discharge clears faster and clogs less.

2. Use corrosion-resistant, slip-resistant floors sloping about 1% toward open channels with a rounded channel profile.

3. Leave spare capacity beyond calculated loads for future expansion and competing water uses—pipe changes after construction are hard.

Sound drainage design keeps inflow and outflow clear so staff can work. Follow CHINENG for free commercial kitchen design support.