Concrete Floor risen after leak - how to fix

[RJRock]

Some advice please.
I expereinced a leak from our dishwasher - not major - about a year ago. Water got under the laminate floor from the end under the kick board. The floor only goes a few inches under the kick board. Leak was fixed quickly and it dried out around the area but a warped risen floor in one area was the result - although not immediate and not too bad. I thought blown boards would need replacing so have now got around to doing the job. I lifted a section of boards as per photos. It was slightly damp but only between the membrane and concrete/tiled original floor.
I then noticed that where the old tiled floor met the new extension concrete floor, the new slab seems to have risen. See photos.
The difference in height being the cause of the 'warp' as the boards I lifted don't seem to be blown at all.

There is no evidence of subsidence around the extension which has been in place 6 years or so, so is the rise in floor due to water going in between the join of old and new floor, causing expansion of the ground below?
What can/should I do to remedy?

There are no damp issues in the the house at all. I've had the floor and membrane up a week now.
When I laid it 6yrs previously there was only a few mill between heights of floor, not spongy or noticeable when floor laid/walked on.

Any help/advice most welcome.

Untitled

• RJRock
• 7 Jan 2011
• 1

Untitled

• RJRock
• 7 Jan 2011
• 1

Untitled

• RJRock
• 7 Jan 2011
• 1

 

[tim00]

1. there seems to be a bit of a "blue" membrane showing at the slab join - am i correct? Is the membrane under the new slab? am i looking at the new concrete or the new screed topping?

2. given the ragged join did BCO pass the extension? How was the slab constructed: materials and dimensions please? who did the work?

3. ground heave would typically cause the extn slab to crack.

4. are there any other structural signs of movement eg. exterior or interior wall cracks, esp. where new joins old, any door or window head slumps or difficulty opening? where does your main drainage run?