How do I repair sunken block paving?

Posted by Trish Altieri, on Wed 04 Dec 2013 08:34am

An area of block paving at the front of our garden has started to 'sink'. And come away it's more the edging bricks. It's starting to look unsightly but it's also hazard. The other day my mum fell over so I would like to fix it. Could you please advise how I should approach this job? Once I remove the block paving that's sunk do I build up the area with sand and cement? I'd appreciate some guidance. Thanks.

Radoslaw Tober

Wed 04 Dec 2013 12:28pm

Hello Trish The must be a reason that the paving has sank., most common one is poor base preparation it the original job, this is the most important part of the job a good foundation will make the paving last and and be problem free. To understand how the base should be prepared you can go to youtube and enter ,,Prepare a Paver Base - How To - Menards" Depending on the material used for the paving and the its size there is a number of ways to finish the last screed most used are - dry sand or a dry sand and cement mix. The second important thing to remember is to make sure the paving has a slope to allow for the water to drain away from any building/s and of the patio. Any water ways or pools can resort in the base to be washed out and in the end for the paving to brake and sink or both. Keeping the above in mind to ,,Fixing a low spot - bed preparation" visit youtube for a short instruction video. Please keep in mind that fixing a section in the wrong way or on the poor base may finish with the problem repapering with time or even worse if the good base is disturbed when fixing the effected section it may spread and more work may be needed. Hope this helps Radek

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David Halliday

Wed 04 Dec 2013 10:23pm

Hi Trish, Lift up the sunken area, remove the layer of sand, remove the layer of stone chips if there is any but I'm guessing there won't be or it will be insufficient. The layer of chips is very important this acts as your sub base and is basically the foundations of your driveway. No cement should be used under block paviors. The stone chips should be no less than 2 inches/ 50 mm and should be compressed using a " whacker plate" to form a good solid base. Then a layer of concrete sand is layer and levelled off " screeded" using a wooden Batton. Then you relay your paviors. Pour kiln dried sand on top and whack back down into position. Jobs a good un! Regards, Dave Edinburgh Stonecraft.

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Michael Tucker

Wed 04 Dec 2013 03:33pm

Hi Trish, I would suggest that when you have taken up the blocks that have sunk you put stone down and compact the area. Simple job to rectify, just give some thought to why it's sunk. Advertise the works on rated people with a budget of £200 Regards Michael.

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