How to fix patio pavers sinking or rising and a gap growing at the joints?

[MikeDP]

Hi

I'm looking for some advice on what you think is happening and what I can do about an issue we have with our patio pavers which are set on concrete slabs.  There are 3 areas , a)1 under cover, b) 1 in front of the front room and c) 1 between Patio A and the garden and they are all now at different levels.

Between A and C as well as the drop in height  (maybe half an inch) there is a gap I can now fit a pencil into.

Between B and A there is also a drop of about this size.

The pavers are set on concrete so not easy to pull up and the situation is getting worse. Any advice welcome or suggestions as to who to call in Western Suburbs Melbourne

Thanks

[Dave-1]

Morning @MikeDP 

😕 It seams the ground has settled and potentially still settling. I am not sure how you can raise it back up without profesional help. I have seen various videos of companies that inject an expanding compound to raise slabs that seem to work.

If you have areas that are constantly wet around the slabs that coulkd indicate why the slabs have shifted. If its a recent job (within 2 years) id probarlly be contacting the people that did the job and asking them to rectify it.

Id also like to say howdy and a warm welcom to the Bunnings community workshop Not the greatest answer to your starting within the community but hoping someone else may have some ideas

Dave

[EricL]

Hello @MikeDP 

Allow me to welcome you as well to the Bunnings Workshop community. It's marvellous to have you join us, and thanks for sharing your question about your sinking pavers.

It's fantastic that you've received excellent advice from @Dave-1. I definitely agree with his assessment regarding the soil settling down. I'm afraid this is a sign that water might be passing through this section of your patio area.

Did this happen gradually, or did it occur in a short amount of time? If it was just recently happening, it's possible that a large amount of water has made the soil soft causing your concrete base to settle. I can only suggest doing more investigation on possible causes before you implement a solution. 

Failure to address the cause of the soil settling will mean that any repair applied will not be effective and settling will still occur. 

Let me call on our experienced members @Nailbag and @Adam_W for their recommendations.

If you have any other questions we can help with, please let us know.

Eric

[MikeDP]

Thanks Both for the advice so far. The drop in the first 3 photos has opened up pretty quickly - over the last few months.

The last photo where one patio is higher was like that when we moved in a couple of years ago.  It may have grown but not as quickly.

I assume now the gap is there water continues to get through and make the problem worse. I'll see if anyone else has any ideas but sounds like this may be one for the experts.

[Dave-1]

Morning @MikeDP 

If your house and landscaping is fairly new it could just be the "fill" they have used in your yard has settled. Still a pain but I have learnt that builders dont always do a decent job in leveling a block. (A good quarter of my rocks in my yard I have pulled out from "builders backfill" )

Dave

[JacobZ]

Hi @MikeDP,

I'd also like to extend a warm welcome to the Bunnings Workshop community, it's fantastic to have you join us.

My thinking is along the same lines as @EricL and @Dave-1, that the substrate is either settling, or eroding due to water entry.

I note in your photos that there is a stormwater pipe running through the pavers. It is possible that this is connected to a pipe running beneath the pavers. If a leak has happened in this stormwater pipe, it could be the culprit.

I'd suggest having a plumber do some leak detection on this pipe before any rectification work is carried out.

Let me know if there's anything else I can assist with.

Jacob