Finding out your outside drain is blocked with fat (often called a "fatberg") is a messy surprise. It usually starts with a slow sink or a nasty smell and ends with water overflowing into your yard.
If your outside drain is overflowing or emitting a foul odor, you likely have a "fatberg" situation. Fat, oil, and grease (FOG) may go down the sink as liquids, but they quickly solidify into a waxy, stubborn mass once they hit the cold environment of an external gully. Common Signs of a Fat Blockage outside drain blocked with fat
For hard, waxy fat several feet down:
A blocked outside drain is a messy and stressful occurrence for any homeowner, but when the blockage is caused by fat, oil, or grease (often referred to in the industry as "FOG"), the situation becomes particularly challenging. Unlike blockages caused by leaves or debris, which sit on the surface, fat-based blockages often bind to the inner walls of the pipes, creating a stubborn, concrete-like obstruction that builds up silently over time. Finding out your outside drain is blocked with
While a simple blockage of leaves can be cleared by hand, a fat blockage requires a different approach. Fat, oil, and grease (FOG) may go down
For a proper resolution, professional intervention is usually recommended. A drainage engineer will typically employ one of two methods:
Early detection can save you from a major sewage backup. Look for these warning signs: