Block paving
Sunken or rocking block paving: what causes it and how it's fixed
Two dips where the car sits, a patch by the gate that holds water, or a few blocks that clunk when you walk on them. These are some of the most common things we get asked to look at on block-paved drives.
The good news is that block paving can usually be lifted and relaid. The question is how far the problem goes.
Why block paving sinks
Block paving sits on a thin layer of sand, which sits on a compacted stone sub-base. If that sub-base is too thin, wasn't compacted properly, or has got wet and soft, it gives way under the weight of a car. The blocks follow it down.
Other common causes are a collapsed drain or old pipe under the drive, tree roots, and trench work from utility companies that wasn't backfilled properly.
Why blocks rock or move
Rocking blocks usually mean the joints have lost their sand, or the edges have started to spread. Once the blocks aren't held tight, each one moves on its own. It starts small and gets worse every time a car goes over it.
The fix for a local dip
For a patch, we lift the blocks, take out the old sand, find out why it sank, and build the base back up and compact it. Then we relay the same blocks on fresh sand, compact them back in and brush in new jointing sand. Because it's the same blocks, it usually blends back in well once it's had a clean.
When it's more than a patch
If the whole drive is undulating, the edges have pushed out all the way round, or there are dips everywhere, the base under the whole lot probably isn't up to it. Patching bits at a time just moves the problem. At that point a full relay with a proper base is better value. Our guide on signs your driveway needs replacing helps you tell the difference.
Don't leave it
A dip collects water. Water softens the base. In winter it freezes. So a small dip tends to get bigger, and puddles are a slip risk too. The sooner it's sorted, the smaller the job.
Get it looked at
Send us a photo of the dip on WhatsApp on 07519 945 497 or call 0161 825 8053. We cover Stockport and across Greater Manchester. If it's a simple relay, we'll say so. If it needs more, we'll explain why and give you a free, no-obligation quote.
