Before you call us
Have a think about when it started and whether it has been getting worse. A drain that has been slow for months and has now stopped is a different job from one that blocked overnight, and the answer changes whether we expect roots, grease or an object. Stop using the affected fixtures until we arrive. A quick look outside helps. Find the inspection opening - usually a capped pipe at ground level near the boundary - and tell us whether you can see it and whether it is clear. If we can access it, the job is quicker and we are less likely to need to work inside.
