dpc over 4in cross floor ventilation pipes

[dada]

am building a conservatory. have put in harcore/sand binding. in order to maintain airflow to underfloor of existing house, have had to put 4 x 4in drainage pipes to feed the air under the existing house, and these are fed into telescopic ventilators.
trouble is, i cannot lap the dp membrane up 2 sides of the conservatory because of these pipes. is there a solution?
i thought about puttting a dpm on the base, then insulating it, then another dpm over the inslulation / pipes so that i could then lap it over the dwarf wall and up the existing house wall.
would this be ok or could i end up trapping moisture between the dpm?
help!! PLEASE

 

[alittlerespect]

Suggestion: Take a step back - Take out the vertical sections of the vents where they come up the boundary wall (except for a small stub section) where the vent pipework starts to rise through the dpc - cut a cross (not a hole) in the dpc such that it is a tight fit and can be pulled over the vent pipe - push the dpc down so that it sits flat on the oversite and then use copious amounts of 'duck tape' to seal the dpc around the stub section of the vent pipe, then install your vertical vents, lay the concrete and job done!