Concrete floor lifting Laminate - No Damp that I can see

[Steve West]

Hi guys

Need some advice please.

We had a new Kitchen built about 4 years ago. We had Laminate flooring laid throughout but in the last few months when it was warmer, we noticed a bit of a hard lump in a section of the flooring. Over the months this has seemingly pushed up the laminate flooring to a point where I do not want to walk on or very near to the area for fear of splitting the laminate.

The floor underneath is as far as I know concrete and I believe the builder who lade the floor put all the correct membranes down and a heat reflective foam material. There is no dampness, it smells fine, just has a couple of hard lumps which seem to be pushing up the floor.

I asked my builder to have a look without removing the floor initially and he said that an expansion gap was put around the edge of the floor so its not swelling but he would need to lift the laminate and investigate fully. This is a cost I do not really want to pay out just at the moment. So I rang my Buildings insurance company who were as useful as a chocolate fire guard and they said you need to get it fully investigated before we can agree if it is a claim.

Can anyone suggest what it could be? To look at the floor you can barely notice it has lifted but you can definitely feel it under foot.

There are no cracks in any of the walls, all my windows and doors seem fine. To me it seems like a small part of substrate has moved but I have not idea.

Thanks

 

[JohnD]

The age of your house, and the town your are in, would help.

There may well be a water leak in or under your concrete floor. This is particulaly common in kitchens. Or there may be a leaking appliance, radiator or drain where water is getting under the laminate. This is also particularly common in kitchens. You say your problem is in a kitchen.

Some materials used for hardcore can attack concrete and make it swell and crack. Badly sorted builders rubble containg gypsum plaster can do it, so can slag or furnace waste containing sulphur. I'm told this is common in steelmaking or coal districts, and can be found in whole streets or estates where the builders used such material. If you are in a street of similar houses some of your neighbours may already have had it.

Have you got a water meter? This can confirm the existence of a leak.

I don't see how you can diagnose or rectify the problem without lifting the laminate and looking underneath.

 

[Steve West]

Hi
Thanks for the reply, house is a typical ex council 3 bed semi, built approx 1960 and we live in Epsom, Surrey. Not sure on the soil type could be clay. I have an open plan Kitchen diner, its the laminate near the french doors approx 2 to 3 ft away in the dining area mostly. Nothing appears to be leaking, no radiators near the area and the one rad in the kitchen the pipes go up the wall to the next floor. Dishwasher seems fine, no leaks under the cupboards anywhere. If water was coming through I would expect to see some discoloration to the laminate. It seems totally dry.

The dining room itself is part extended but this was done 30 years ago. There is a small drainpipe which goes in to the ground at the back of the small extension. However I am not convinced this is the problem as the issue started in the summer but has gradually got worse. that pipe has always been there. If this problem suddenly arose due to all this wet weather I could understand it.

No trees close (30 foot at least) have been removed which I hear can cause problems.

I am thinking its the sub floor which possible has got damp and has pushed up but I really have no idea.

I do not have a water meter. The mains supply is to the front of the house.

Looks like the floor and skirting boards have to come up. I was really just looking for ideas before I ventured down this route.

Appreciate the reply.

 

[Alec_t]

its the laminate near the french doors approx 2 to 3 ft away

Perhaps moisture wicking in under/around the door frame, causing the laminate to swell?

 

[Steve West]

The laminate is not swelling. you can feel a solid lump under a small part of the floor. Its like hes laid the floor on a medium sized pebble, but it was fine for nearly 3 years until last Summer and gradually seems to be getting worse.

 

[bobasd]

its typical for a finished floor covering with damp penetration or a floor that lacks expansion gaps to tent up at a more or less central pressure area.

the fact that its getting worse suggests a damp problem?

 

[Steve West]

I have checked back on the build pictures and can see the builder laid a self levelling floor compound, then added an insulation membrane before laying the laminate, I can also see he added spacers around the edge for expansion. So the floor is not pushing up on itself, its a hard lump that is in one part of the floor under the laminate that is pushing up. About the size of a tennis ball in diameter but not as deep if that makes sense.

 

[foxhole]

The floor could have been laid over a poorly finished sub floor, walking on the laminate eventually caused the bumps to wear thru the laminate as it breaks up .
IMO folly to use laminate in kitchens .

 

[Steve West]

Thanks Foxhole, I am going to pull the flooring up and the skirting have a look and see whats there. Then I guess will have to try and fix it. Not even sure what materials I will need but thats something I will investigate once its up. The laminate itself is fine from the top, its not split or cracked yet, so i'm hoping it is still ok underneath, I do have a few spare planks though in case.

My only other issue is should my build be held accountable for it, if it is the floor levelling stuff he put down? I dont want to start pointing fingers just yet though.

 

[foxhole]

Thanks Foxhole, I am going to pull the flooring up and the skirting have a look and see whats there. Then I guess will have to try and fix it. Not even sure what materials I will need but thats something I will investigate once its up. The laminate itself is fine from the top, its not split or cracked yet, so i'm hoping it is still ok underneath, I do have a few spare planks though in case.

My only other issue is should my build be held accountable for it, if it is the floor levelling stuff he put down? I dont want to start pointing fingers just yet though.

Will depend on what you find underneath.