How to lay block paving
A big part of laying block paving is in how you install it. Planning ahead and making sure you have the right tools for the job is a must. Discovering how to lay a driveway or block pavers in general can take you a huge step closer to creating your dream home and garden – so here we’ll show you how it’s done.
How do I lay block paving?
- Dig to at least 150mm below a damp proof course – with a gradual slope.
- Set out a sub-base in more than one layer and compact to 100mm.
- Layer on sand until the space for blocks reaches the desired height when levelled off at falls.
- Lay the blocks – they should reach 15mm above the level before compacting.
- Sweep sand into the block joints and compact the surface. Repeat until every joint has been filled.
What tools do I need?
- String line and pegs
- Screed rails
- Shovel / spade
- Spirit level
- Tape measure
For hire: Don’t forget the cement mixer, compacting tool and block splitter.
Always check your lines at every step – ensure layering is levelled off and correctly sized up to avoid mistakes.
Step by step guide to laying block paving
Once you’ve got an idea of the size of the block paving area, dig out the area to a depth at least 150mm below the damp proof course of your house, or whatever the paving will sit next to. Depending on the rise and fall of the land, the depth you’re digging may change as you progress further into the area.
You’ll need to dig in a gradual slope so that surface water can run away from the area or into your drainage system if one is being installed. We recommend a 1cm drop for every 60cm of length that’s being paved.
Edge restraints frame your driveway. A concrete foundation holds the blocks in place, and gives the paving the strength to support cars or other vehicles.
Use a concrete mix of one part cement and six parts ballast to create the foundation. Then, when the concrete dries, lay the blocks as an edge course on a bed of mortar. A taut string line should act as your guide, and should be set at the finished height of the paving level
Mix the concrete 25mm below the line and place the edge course on top. Hammer in gently using a mallet and check the line for its level. Haunch in the edging by applying concrete to the outside, which should reach about halfway up.
As the main supporting layer of stone, you’ll need to apply a layer of at least 100mm of sub-base. This will make sure the paving can support the weight of people and vehicles.
Spread the sub-base material evenly inside the edge restraints and rake evenly. Do this around 50mm at a time, before firming down the layer using a compacting plate. Take six or seven passes using the compactor to ensure it’s thoroughly packed down – it’s important to do this so your paving blocks stay level and in good shape for years to come.
Add sand to make up the distance between the sub-base and the line of the final paving, carefully moulded to incorporate the slope and any other angles. Choose a good sharp sand – moist enough that you can pack it in a ball with your hand – and spread over the sub-base. Lay out a layer of sand and pack it down with a single pass of the compactor.
Before you get to laying the blocks, it’s time to level off the sand by screeding it. Insert your screed rails – timber will do – into the sand and make the tops level with the bottom of the final layer of block paving. Then scrape a third piece of timber along these rails to rid the bed of excess sand, and adjust for falls.
Laying paving blocks
Start laying blocks from one corner at the bottom of the slope – in a corner where possible, or at least up against a straight edge or border. Blocks should be placed straight to the face and slid down. Don’t bunch them up along the surface of the sand or they won’t line up – put each one down flush where it should go. Use the block splitter or a diamond disc saw to cut blocks down to size at the edges.
Blocks should be hitting 10-15mm above the line you’ve planned – ready for compacting down once the course has been completed.
What sand should I use for block paving joints?
Sweep kiln dried sand across the paving, getting plenty of it into the joints. Compact down the paving before adding more sand. Repeat this process until every joint has been filled with sand.
For more information on laying block paving, watch our video guide to block paving a driveway below.
Prefer your block paving to be installed by an expert? Click here to find your nearest Marshalls-accredited installer.
Monday, 1st February 2016