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? 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

Driveways that do not sink

We hope this has been of some use and contact us before sinking gets out of control!