The client contacted us with an overflow that was constantly leaking.
Builder had tried to fix the problem with copious amounts of silicone.
Unfortunately, silicon does not bond well with polyethylene.
Once on site, we found that the reason the overflow kept leaking and more silicon was constantly needed was because the overflow pipework was too high for the overflow outlet in the tank and was causing pressure on the fitting.
We removed the fitting and the pipework and installed a flanged overflow with rubber gasket.
We then lowered the overflow pipework that connects to the tank.