We are having a new kitchen fitted, during the strip out earlier today, our kitchen fitter found some unexpected results.

Underneath the current floor tiles were the chipboard floor tiles.
The chipboard floor tiles were discoloured and very soft and damp.

This was in the middle of the kitchen floor, the damp is not coming from any adjoining wall.

The polystyrene insulation was still in place but damp.

Underneath the insulation, the membrane protecting the concrete floor was intact, the concrete underneath the membrane is dry.

We are a little bewildered, the water pipes are running beneath the concrete floor and are not leaking.

Any ideas or suggestions appreciated.

Don’t wee in the kitchen?

Just a crack in old tiles/grout letting water down when you wash floor?  It takes an amazing amount of time for stuff to dry out after if there isn’t an open surface

And don’t wee in the kitchen of course

I would go with leffeboy – just water that find it’s way in from mopping that can’t find it’s way out.

Poltergeist

Why would you have a membrane under the insulation and cork tiles would be my first question if the original concrete floor is dry? Strip back fully and wait for fridays rain then inspect the original concrete floor would be my best advice. If that stays dry then crack on.

The house was a new build about 18 years ago.

This is the first time we have had the floor up.

The concrete is fine, no signs of damp anywhere.

Your washing machine is, or has been, leaking?

No, washing machine hasn’t leaked.

The washing machine and dishwasher are located against the kitchen walls.

The worst patch was in the middle of the kitchen, away from any potential water or walls.

No, washing machine hasn’t leaked.

The washing machine and dishwasher are located against the kitchen walls.

The worst patch was in the middle of the kitchen, away from any potential water or walls.

In twenty odd years of working in social housing refurbishment, I’ve lost count of the number of rotten kitchen floors that i’ve seen just as you describe.

It’s almost always the washing machine.

It’s almost always in the middle of the kitchen floor.

The machine leaks a little, not enough for you to notice a puddle, the water runs through the small gaps in the flooring to the lowest point in the kitchen floor, usually the middle as that ‘s the bit that flexes a little under the dynamic load of people and isn’t supported at the edges.

Thanks perchpanther

Will keep a very close eye on it, when re fitting.

I’m still at a loss to know why a new build would have chipboard floor tiles over a concrete floor with insulation under it????

Don’t wee in the kitchen?

When I saw the thread title, I was sure this advice would appear in the first five replies.

I’m still at a loss to know why a new build would have chipboard floor tiles over a concrete floor with insulation under it????

Our house has this; it’s a typical naff construction from 20-30 years ago. Concrete floor. Polystyrene slab. Polythene sheet. Chipboard. Floor finish. A horrible solution especially when the chipboard slabs weren’t glued together and they begin to move and creak and then you get a leak and the chipboard turns to something resembling Weetabix and stinks like a Blackpool dosser.

I’ve worked in construction for 25 years or so now and I’ve never come across it. What a shit design!

Which company built your house Denis99 ?

Persimmon

Floating floor
It’s very common in new build houses.
Nothing wrong with it if installed correctly.

It’s very common in new build houses.
Nothing wrong with it if installed correctly.

And there lies the problem…

Tiles aren’t actually waterproof. If you’re replacing the floor it’s probably worth adding a waterproof decoupling membrane below the tiles to protect the boards. Wedi subliner or Schluter Kerdi or similar.

Floating floor
It’s very common in new build houses.
Nothing wrong with it if installed correctly.

What are the benefits? I see none other than letting groundworkers launch the sub floor down erractically and quickly. I’d never use anything timber based on the ground floor.

What are the benefits?

Time is money and Persimmon are not known for outstanding quality. Big house-bashing jobs were never my favourite gig. Too much concentration on paper in files and no practical application of the paper’s contents. Plus bonuses dependent on your part of the job finishing early.

What are the benefits?

People don’t like walking on concrete floors in their houses. They’re cold and hard and unforgiving.

Punters prefer the feel and sound of timber.

Selling new build houses is all about the feels.

It’s not a new concept. The kitchen in my 1896 house has a timber floating floor over a concrete slab, although that’s because it was converted from an original wash-house.

I’ve built a few perchy, always used an insulated slab.

Yeah, but you don’t strike me as being “all about the feels”  though. 😉

Building them isn’t the same thing as selling them. People are  largely irrational when they buy houses. It’s the weird, emotion inducing, touches that sell houses, not the construction details.

You and I would  look at them with a measuring tape rather then be  be wowed by some fabulous curtains and unnaturally small furniture in the show house.

We’re not typical though.

unnaturally small furniture in the show house.

Ahh…. that’s why my legs look longer than they really are 🙁