Repairing a DPM

[jayc89]

Our new floor slab was laid on a DPM, which lapped up the walls. The detail is MOT, DPM, Conc, PIR, Screed.

 

We had another section of the floor which was to be block & beamed (over an old cellar). The detail should be B&B, DPM, PIR, Screed.

 

I've come to lay the new DPM over the block & beam, joining it to the existing slab's DPM to find it's been cut, where I need to join it, at the slab level, so I have nothing to join it to. 

 

What's my best option here? A liquid DPM between the two?

[Simplysimon]

if there's enough to lap it over then a double sided dpm joining tape others available