A dishwasher leaks sideways and underneath, which is why you find it late.

The kickboard is the panel along the floor at the front of the units. It comes off with a firm pull or two screws, and behind it is the only honest view of how far the water went. Do this before deciding whether the problem is small, because from the room side it always looks small.

A torch along that gap tells you more in ten seconds than an hour of mopping. You are looking for standing water, dark swelling at the bottom of the cabinet sides, and whether it has reached the units either side.

Most fitted kitchens are built from melamine-faced chipboard. It absorbs water at the cut edges, swells to perhaps twice its thickness and never returns. A swollen cabinet base cannot be dried back into shape, so the question a crew answers is not whether to dry it but which units have to come out.

Solid timber and plywood carcasses behave differently and can often be dried in place. Knowing which you have changes the scope of the job significantly, and the cut edge under the kickboard is where you can tell.

The floor under a fitted kitchen is usually continuous beneath the units. Water there is out of reach without lifting the kickboard or drilling access, which is why kitchens are the most frequently under-dried room in the trade.

A door seal that split, a pump housing that cracked or a supply fitting that let go are sudden failures, and standard homeowners wording answers for the damage. A machine that has left a small puddle after every wash for a year is maintenance, and that damage falls into the gradual-loss exclusion along with any mold.

Insurers ask how long, and an honest answer is better than a guess: the physical evidence usually tells them anyway. Swelling that has dried and re-swollen looks different from a single wetting.