What does a water leak have to do with a bird? Well, sometimes we get call outs to a water leak where the ceiling is full of water and it’s right below the air conditioner. All air conditioners have what’s called a ‘P’ trap and this is there to let the water drain away from the unit. It has a trapped bit of water so that air can’t come in or out of the unit (similar to the ‘U’ pipe under your sink).

Roof top air conditioning units tend to have the ‘P’ trap on the side so that it can just drain onto the roof and then use the existing drainage system. BUT, on a hot summers day, when water is in short supply, birds know that there is water in the trap. Being highly intelligent, they go collect rocks and drop them into the trap, raising the water level so they can take a drink! Over time your drain trap becomes clogged with these rocks to the point that the water can no longer drain, causing the air conditioner to fill with water and leak into your building.

A good maintenance program is essential for roof top units, and another easy fix is to put a 90 degree fitting on the end of the trap so the birds can no longer reach the water.