Belt and braces for Wedi board

[Mr potato]

I am looking to fit a wedi tray with wedi backer board and am concerned with the jointing method. Wedi website advises butt sealing the boards and using their tape, bonded with a cement based flexible adhesive. The tape provided does not look waterproof and a cement based adhesive certainly wont be. The tray and board will only be as good as the joint, therefore should I use a flexible epoxy adhesive such as Mapei Keralastic to bond the joints and tape to give a fully waterproof joint.

 

[DHTiling]

As long as you have 50mm overlap either side then it is fine to use what is recommended.. works ok for me..

 

[Mr potato]

Thanks for the advice. I have now seen the tape first hand and it has a rubberised centre which now makes sense.
Thanks again.