There are three main causes of block paving drainage problems:

Block paving drainage problems – Laying on a concrete base

If there’s a fall (slope that drains either naturally or to installed drainage) blocks can be laid and there shouldn’t be a problem. However, if there’s not a fall then water will simply sit underneath the blocks and this will cause organic growth (weed and grass) and this will make the blocks lift. The only remedy to this problem is to resinstall the driveway. Nobody wants this problem (see below).

Read block paving insallation

Block paving drainage problems – minimal or no aggregate (stone) sub base

As unbelievable as it seems it has been known for some block paving driveway installers to lay block paving on a bed of sand without first installing a suitable sub base. This type of shoddiness is less common now but for many years a lot of block paving driveways were laid like this. These types of installation are easy to spot. They’re the ones with large ‘ruts’ where a vehicle has been rolling over the same spot. Over time the ruts get deeper and the blocks start to break away from eachother.

concrete blocks

What has made this block paving sink?

Block paving drainage problems – Channel drainage not fitted properly

Linear drainage (channel drainage) systems are used extensively on many driveway installations. Further to SUDs legislation permission is needed if water drains to the public highway. Therefore many block paving installations now have channel drainage fitted as standard. The types of channel drainage range from block that blend in nicely, like below:

channel drainage

Large block paving channel drainage

To Aco or Clark channel drainage systems (with either metal or plastic grills/lids)


Block paving with Metal Channel Drainage


plastic channel drainage

Block paving with Plastic Channel Drainage

Unfortunately, there are some very cheap types of channel drainage systems mainly sold by the leading DIY chains and online. These types of channel drainage twist and do not have large weight bearing capacities.


Cheap channel drainage lifts easier (with or without weeds!)

But the worst (not the best) of problems has been saved for last.

Look at the picture below. Not only has this block paving been laid on a concrete base with no soakaway installation but cheap and nasty drainage channels have been used. So where is the water going to drain to?

block paving channel drainage

Block paving laid on concrete with pointless channel drainage installation

Read more on soakaways

At drivewaywise we often hear stories of shoddy work. The culprits are often those looking to make a quick buck with property renovations. If you are aware of these types of jobs just let us know below, so we can assess and provide assistance. This type of poor practice reflects badly on the majority of driveway installers that create marvelous driveways. It must be stamped out.

Drivewaywise explain the pros and cons of driveway surfacing products, enhance the reputation of the driveway industry and bring to light instances of poor practice. 

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