I have just built a single storey kitchen extension with a 150mm reinforced concrete oversite base. The building regs required me to install a DPM under the slab and another (more substantial) dpm layer on top of the slab prior to laying 60mm of insulation and an 60mm screed.

The central heating pipework will be laid in the screed. When testing the pipework, I had a dry joint in one of the pipes and had a flood!!
The water got under the DPM and wet the slab and blinding layer.

Can anyone advise me if this needs to be completely dried out before i put the screed down? I have exposed part of the slab by removing the insulation and peeling back the upper dpm and this has slowly dried over the week but the dpm is keeping the wet in where its still covering.

If i lay the screed next week, this moisture will be sealed in by a dpm layer above and below the 6" slab, will it cause damage to the concrete or reiforcement?

Thanks.