Do I have to dig out for a channel (perimeter drain) when installing a cavity drainage membrane system in a cellar?

No, you do not, but in this case provision should be made for a high-profile drainage membrane to be installed to the floor. Also, the height of the floor within the boundaries of the channel will have to be made up in order to get to the same height as the top of the perimeter drainage channel. We have a CAD drawing illustrating this (XV-019-3) (http://www.safeguardeurope.com/cad/XV-019-3.pdf). For further information on Aquadrain perimeter drainage channel, please click the following link: http://www.safeguardeurope.com/products/aquadrain.php