A fat blockage forms when warm cooking oils, animal fats and dairy residues poured down kitchen sinks cool and solidify against the pipe wall, gradually narrowing the bore. When fats combine with wet wipes, sanitary products and other non-flushable items, the resulting mass can grow into a fatberg, a term widely used in London since the well publicised Whitechapel and Kingston cases on Thames Water mains. Fat blockages are most common downstream of kitchens, restaurants and food preparation areas. Engineers usually address common causes by high pressure water jetting in accordance with industry practice, followed by a CCTV inspection. Building Regulations Part H and BS EN 1825 require grease separators in commercial kitchens. For domestic prevention, scraping plates and avoiding pouring fats into the sink remain the most effective steps.
Fat blockage (fatberg)
Solidified mass of cooled cooking fats and oils blocking a drain, sometimes combined with wipes.
