Hole under kitchen floor??

gramlab

Getting a new kitchen and the old one was taken out this morning. I was taking up the old tiles when I noticed a section of the floor was loose. This is in the corner of the room under a radiator.

The was a small hole and I was able to put a file into it about 6 inches. It feels like I'm touching sand or something (not wet though). I can basically prise a the section of the floor (about 6 inches square) up and down.

This has me really bloody worried as all sorts of nthings are going through my head. I had an extension built onto the kitchen about 3 years ago (onto the outside of the wall the hole is next too. I had an engineer who oversaw the whole thing.

What could cause a void like this under a floor and who would be the best type of engineer / builder to have a look at it.

New kitchen was due to go in monday. I currently have an empty room with a half pulled up tile floor. Merry chrismas in store for me.

Have some pics but dont know how to add them.

Any ideas??

mickdw

If you have a floor screed, this is a non issue. The screed is placed over the structural subfloor and may have pipework running through it. It is not uncommon for a section to come loose. Cracks can form over the run of a radiator supply pipe for example. If there was then a small area of floor between the crack and a wall etc, that section could come away. Depending on construction of the floor, this screed may be completely seperated from structural floor underneath by insulation and very susceptible to movement and cracking particularily if there is not at least 75mm of screed . I wouldnt be overly worried at this stage. I would continue with the removal of tiles.
If there is was not a screed used and this happened to be a crack in the main structure, I highly doubt you would be able to prise any of the floor in anyway.
You may have to replace some of the floor screed but it shouldnt be a major cost.
Get an Engineer to have a look to be sure.

muffler

mickdw wrote: »

If you have a floor screed, this is a non issue. The screed is placed over the structural subfloor and may have pipework running through it. It is not uncommon for a section to come loose. Cracks can form over the run of a radiator supply pipe for example. If there was then a small area of floor between the crack and a wall etc, that section could come away. Depending on construction of the floor, this screed may be completely seperated from structural floor underneath by insulation and very susceptible to movement and cracking particularily if there is not at least 75mm of screed . I wouldnt be overly worried at this stage. I would continue with the removal of tiles.
If there is was not a screed used and this happened to be a crack in the main structure, I highly doubt you would be able to prise any of the floor in anyway.
You may have to replace some of the floor screed but it shouldnt be a major cost.
Get an Engineer to have a look to be sure.

Good advice mick.

Just to add that if in doubt and as suggested by mickdw get an engineer to gave a look. If you're happy enough and have confidence in your local builder get him in to rip out that section of the floor. Its better to see whats there before you go fitting a new kitchen. From what you have described it doesn't appear to be serious at all but get it checked in any event.

There's a handy and simple little site here for uploading pics and if you want to practice at any time you can mess about in the test forum

Sonnenblumen

mickdw wrote: »

If you have a floor screed, this is a non issue. The screed is placed over the structural subfloor and may have pipework running through it. It is not uncommon for a section to come loose. Cracks can form over the run of a radiator supply pipe for example. If there was then a small area of floor between the crack and a wall etc, that section could come away. Depending on construction of the floor, this screed may be completely seperated from structural floor underneath by insulation and very susceptible to movement and cracking particularily if there is not at least 75mm of screed . I wouldnt be overly worried at this stage. I would continue with the removal of tiles.
If there is was not a screed used and this happened to be a crack in the main structure, I highly doubt you would be able to prise any of the floor in anyway.
You may have to replace some of the floor screed but it shouldnt be a major cost.
Get an Engineer to have a look to be sure.

Sounds like a gerry building finish, which any competent plasterer could do easily. The fault would clearly indicate the original screed was inadequate including poor mix (why break), ininsufficent depth ( 75mm would be a optimum minimum but if you can reach down 6" and touch sand, whats under screed?), i wonder what sub-base (should be concrete) is present. Best practice would advise that screed be protected and/or re-inforced against potential damage from nearby pipework.

Do you really need an engineer to identify the faults here? A competent plasterer/tradesperson would or should suffice, saving you fees for the obvious required remedial works.

A diabolical but not untypical example of careless workmanship when completing a straightforward piece of work.

Best of luck OP.

gramlab

Thanks for the advice folks.

Got a site engineer (husband of wifes friend) to have a look. Took out the loose section and found a void underneath. He said it was probably due to a leak in the rad pipe that must have sealed itself up (sand was dry)

Packed sand in there and 2 inches of non shrinking grout on top. Sorted I hope.

I was worrying and picturing a major job - fingers crossed.