I have just started the renovation of our old family home. First job is a utility room with a shower. Its some years since I have had a building project and I see XBS backer boards are a popular choice for shower surrounds so that's what I have used (Jackoboard). I have got a Mira Flight tray. I want to be belt and braces on waterproofing so got a shower sealing kit which comprises of a primer, sealing tape and a liquid waterproofer. Jackoboard is supposedly none porous so I haven't used the primer and this was confirmed as the correct option from the technical helpline for the waterproofing. Where the tape seals between the shower tray and the wall the instructional video shows cutting the perforated edge off the tape and then pressing it into a layer of the waterproofing paint. This is where it's gone wrong as it has not bonded to the tray at all and not especially well to the Jackoboard. I really dont want to strip everything off if I dont have to but can you see a way to reseal this edge and what I did wrong?
Thanks
Beau