What Is a Belfast Sink and How Is It Fitted?

What Makes Belfast Sink Fitting Different

A Belfast sink is significantly heavier than a standard undermount or inset sink — typically 25–60kg depending on size. It must be supported on a dedicated base unit or custom-built support rather than simply resting on the worktop as a drop-in sink would. The worktop or unit front must be cut precisely to accept the sink apron.

Installation Steps

• The base unit must be built or modified to provide solid support for the full weight of the sink
• The worktop is cut to the correct depth to allow the sink to sit at the right height
• The waste fitting and overflow (where applicable) are connected before the sink is positioned
• Supply connections are made by a plumber after the sink is in place

Planning Considerations

Belfast sinks project further from the wall than standard sinks, which affects the worktop depth required. The waste position must also be planned carefully as the deep bowl creates a low outlet point. Discuss these requirements with your kitchen fitter and plumber at survey stage.

Belfast Sink vs Standard Inset Sink

Retrofitting a Belfast Sink Into an Existing Kitchen

Adding a Belfast sink to a kitchen that wasn't designed for one usually means replacing the base unit beneath it entirely, since standard cabinets rarely have the strength or the correct front cut-out — this is worth costing separately from a simple sink swap.

Do Belfast Sinks Need a Special Waste Kit?

Often yes — because the bowl sits lower and the front apron is exposed, standard waste kits designed for inset sinks may not give enough clearance underneath. Check the waste kit is specified for Belfast or butler sink installations.