Why has my block paving sank?

Why has my Block Paving Sank?

It’s irritating and gradually happens over years. If block paving is left to sink it can become a trip hazard and for late night stragglers potentially dangerous.

Exceptional cause

In exceptional circumstances sinkage is caused by water table levels rising and in turn sub soils becoming soggy. Any type of sub base, no matter how good, which is on top of a soggy sub soil will sink. But this scenario is exceptional.

Why has my Block Paving sank? The most common cause

Most block paving sinkage is due to insufficient support from a sub base. For many years (prior to the wide use of Type 1 MOT stone) driveway areas were filled with left overs from building sites commonly known as ‘hardcore’. For many block paving installers ‘hardcore’ was used in sub base preparation and covered with sand. The problem with this is that huge gaps form and after time these holes fill with sand and in turn the top layer of block paving sinks.

Why has my Block Paving sank? Less common cause

Driveway extensions are another cause of sinking block paving. If you you want to extend you driveway area even more support and a deeper sub base preparation is required.  This will avoid block paving collapsing around the edges.

Why has my Block Paving sank? Common Myths

MYTH 1 Vehicle weight has made my block paving sink….No, this isn’t possible. A driveway area that is already sinking will sink further and faster with the weight of vehicles but this is not the cause.

MYTH 2 Poor quality blocks….again this will not be the cause of sinking but cheaper manufactured blocks will probably also probably been laid on on a cheaply installed and poor quality sub base.

Why has my Block Paving Sank?

If large areas of your driveway have sunk, you might need a professional to restore your driveway.

How do I fix my sinking pavers (DIY style)?

In order to raise the sunken blocks in your driveway and to make your driveway even again, you will need to fix the subbase.

In other words, you will need to remove the sunken blocks and fix the subbase.

Here’s how to go about it:

1. Remove the sunken blocks and some extra blocks around these.

You can do this by using a screwdriver to aggitate the sand around the blocks. Keep moving the sand until the blocks are lose enough to remove.

2. Add all purpose sand to the subbase and level it with a creeder or plank.

You need to make sure that the sand is level with the bottom of the surrounding blocks.

3. Compress the sand as much as you can.

You can do this by walking on it or by pushing down a heavy object.

4. Replace your blocks

Remove any sand and dirt from the blocks and place them back on the subbase.

5. Fill the cracks

Fill the cracks with sand and brush away any excess sand.

6. Re-seal your driveway

In order to make your driveway look like new again, wash of your driveway and give it a reseal while you’re at it. An easy DIY job and a cost effective way to make your driveway last for years again.

Read how to reseal your driveway in easy steps here.

Why has my Block Paving sank? What to do about it?

Depending on the extent of the sinking a block paving repair may be possible but if the driveway area has been sinking for some time a new block paving installation may be necessary. Of course if you are in the market for a new driveway there are other choices available:

Modern driveway options

Driveway surfaces  that do not sink

When your block paving has sank in small areas, you can fix it by the steps above, where you remove the blocks and fill up the sand underneath. 

It’s annoying when your driveway starts to look old and the surface becomes uneven. It’s dangerous to walk on and can cause accidents, especially in the dark. It’s therefore recommended to restore blocks which have sank as soon as you can. 

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