Kitchen laminate when stepping on water coming through

Possible leaking pipe under floor or no membraine installed

I would personally remove the laminate flooring… as the water has probably damaged the flooring already with it been wood. Then you try find your problem or at least where the source of water is coming from. You would then address this issue. And then chose some lovely new flooring your non leaking kitchen. That’s my judgement with out seen the actual problem it’s self Have a lovely day

Possibly no membrane under concrete floor

You should do what Luxury carpets have advised.

Membrane damage or membrane missing can be for sure

You won't be sure until you find the source of the damp.weather it is coming from a pipe or under the laminate itself will depend on how you proceed. I would look for the source by looking around the affected area also by lifting the laminate.

You will need to lift the floor an investigate cause. If it's rising damp then you can lay a floor tanking membrane and new laminate over. If it's high water table then floor membrane with perimeter drain, maybe even sump & pump. If there's a pipe leaking under the floor then you'll need to break out the floor around the leak & repair. But let the floor dry out before laying anything over. Hope that helps!

Best to remove the laminate to investigate further and dry out. I completed a similar job and found a slow leak (slight dripping over approx 3years), which sat between 2layers of concrete and under the lino.

either no membraine installed or possible leak.

I would first of all suggest removing the existing flooring. Even by if it was to be dried out, it would never go back to its original state. One the floor has been uplifted the cause will more than likely be very visible with one or more parts of the sub floor looking more saturated. If visible that it is pipework you will need to call a plumber out to repair the works, same for appliance issues. Once this has been dealt with I would recommends leaving the sub floor to dry for some time. Even though it may look dry, the sub floor can still hold moisture. You do not want to cover with new materials if moisture can then possibly travel into the new. A damp proof membrane can be installed before any new floor coverings are installed to reduce further risk.