If the existing drain has a clamping ring assembly, remove the strainer, clamping ring bolts and clamping ring. Clean the drain bowl, clamping ring flange and clamping ring. Do not allow debris to clog drain pipe.

Install the field membrane over the drain. To determine where to cut the hole, place the drain clamping ring over the membrane onto the clamping ring flange. Allow the membrane to extend 2.54cms past the clamping ring.

After the membrane has been cut, lift the membrane and apply several heavy beads of Water Cut-Off Mastic to the clamping ring flange. It is recommended to use a minimum of ½ tube per drain.

Align the clamping ring over the membrane and punch holes where necessary to install the clamping ring bolts. Do not cut the membrane back to the bolts. Finally, secure the clamping ring and install the strainer.