Sinking Concrete Floor (Subsidence?), How To Repair?

bagels

I'd be very grateful for advice on how to solve a problem i have with my Hallway Floor.

My house is 30 years old and the front is on a slope.
At the point where my driveway meets the public footpath, it appears that the driveway has risen, leading me to suspect that the driveway is sliding down the slope.
This is what leads me to suspect that the fill underneath my Hallway floor is settling or sliding away.

I want to tile my hallway floor but am worried that the floor is unstable.

Frequently when i enter or leave through the front door and step on a certain part of the floor, i hear a distinct 'clunk' sound and get the feeling that the floor is giving way underneath me.
There is a crack on the floor near the front door, extending about a metre into the hallway.

I'm afraid theres a hollow area underneath the hallway floor that allows the floor to drop when stepped upon.
If the floor has movement in it, then i can't risk tiling it as the tiles would probably break due to the movement.

What can i do to accurately diagnose the problem & fix it?
Will i have to dig up the floor & replace it?
Is there any other solution, eg drill through the floor in several locations and inject something down into the hollow area (if it exists)?

I don't have any construction experience, just a bit of diy, so please excuse me if i've made a poor job of describing the problem.

Thanks in advance for any advice.

RKQ

bagels wrote: »

What can i do to accurately diagnose the problem & fix it?

Retain professional advice - a Structural Engineer can determine if it is subsidence. I do not see any connect to you driveway sinking and your hallway floor. (You do mention any cracks in your walls or any other symtoms of subsidence).

Subsidence wouldn't neccessarily show itself as a "distinct 'clunk' sound and get the feeling that the floor is giving way underneath me". Its possible that its a small void in the slab or filling which can be repaired.

bagels wrote: »

Is there any other solution, eg drill through the floor in several locations and inject something down into the hollow area (if it exists)?

This system exists for floor & foundation subsidence.

bagels

RKQ wrote: »

Retain professional advice - a Structural Engineer can determine if it is subsidence. I do not see any connect to you driveway sinking and your hallway floor. (You do mention any cracks in your walls or any other symtoms of subsidence).

Subsidence wouldn't neccessarily show itself as a "distinct 'clunk' sound and get the feeling that the floor is giving way underneath me". Its possible that its a small void in the slab or filling which can be repaired.


This system exists for floor & foundation subsidence.

Thanks for replying.
Unfortunately, I can't afford the services of a structural engineer.
I don't have any other cracks on floors or walls.
Is there any diy way I can find out if the floor actually moves?
If it doesn't, then perhaps i can just try to fill the void, assuming it exists.
Thanks again for posting.

bagels

Sorry, double post.

RKQ

You are welcome, glad to help.
Unfortunately without seeing your floor I can't comment any further. Moderators don't like posts on structural matters, so I don't want to get either of us banned.

bagels wrote: »

Is there any diy way I can find out if the floor actually moves?

You could tap the floor to hear differencies in sound. A hollow sound would indicate a void. A small void in the slab or underneath the slab could be repaired before laying new tiles.

"Help my house is falling down" is quite a good tv programme on Channel 4. It shows people with really bad subsidence, sinking floors, dry rot etc. Sarah offers comprehensive advice & solutions. Sometimes the strapped for cash owners are offered DIY solutions to their problems. Worth a look.:)

Martron

post a picture if possible of your driveway and around the hall door. ic ould be something else.

bagels

Thanks for the advice everybody