Aarsleff applies hat profiles for both rainwater and waste water pipes. The hat profile provides a tight transition between main pipe and lateral. In addition it strengthens the pipe where cuts for laterals have been made.

The Aarsleff Hat Profile is made of acid-proof polyester fibre impregnated with resin. It consists of a brim and an endless crown and is tailor-made on site to fit the job in question.

The hat profile is mounted on a tool that monitored by a TV camera is pulled to the lateral in question. When the tool is in position the brim is pressed into place whereupon the crown is pushed into the lateral. After this the hat profile cures and the tool is retracted.