Let Me Build It!

Compacting the hardcore
Once you have removed the existing drive patio or path and excavated to a minimum depth of 200mm (100mm hardcore, 50mm sand, 50 mm block) your hardcore needs to be compacted to give a stable sub base for your new block paving

Fixing a firm edge restraint
Any area of block paving must be surrounded by a firm edge restraint to prevent the blocks and the sand on which they are laid from creeping, either the house walls, fence base panel or new edgings along any side which require the paving to be held in place.

Using a tight string line to keep the front edge of the edging block in a straight line, the blocks are laid on a semi dry mix of 3 parts sand to 1 part cement and hauched front and back to hold in place

Zone 2 grit sand
Zone 2 grit sand is layed to the entire area approx 30mm higher than the finished height to allow for compaction. Different parts of the country have different grades of sand and as a rule of thumb get the coarse grit sand rather than a fine grain sand

Using a spade level the sand roughly to the correct height

Continue over the toal area untill you have covered all the hardcore

As a rough guide 1 ton of sand will cover approx 10 square metres at 50mm deep

Compact the grit sand
Once you have filled the entire area with sand this needs to be compacted with your vibrating plate, you will see the lines and your footprints going less and less after going over your sand 2 - 3 times. It’s advisable to have your sand harder and higher than to leave any low soft spots

Getting the correct finished height
Using a block as a guide push back and forwards and down into the sand until it is 5mm higher than the finished height to allow for the final compaction

Steel poles for a perfectly flat finish
Use a tight string line as a guide cut a channel in your sand to allow the 18mm steel poles to sit, they can be bedded up or down to the required height. The top of the screeding pole is the underneath face of your block so allow 55mm to the finished height

Using a tight string line to get the pole to the correct finished height prior to screeding, check the poles for being level or falling towards any drains, 1:60 fall is required, that’s 1″ in height to 60″ in length

The string line can be held in place either by using 2 - 3 blocks or alternatively you can use steel road pins

Screeding the sand
Once your steel poles are in place you can begin to screed the sand to the correct height prior to laying your blocks. When finished remove the poles and fill with sand using a steel trowel to give a smooth flat finish

Laying the block paving
The block can be laid either square to the house or on a 45 degree angle. On this drive the full blocks started at the front corner of the house working towards to boundary edge restraint. It was done this way so full blocks showed all round the house and any cuts were only visible at the garden side of the drive

The main area of the blockwork completed showing the border, the next step is the cut blocks

Cut in the edges
When you have completed the laying of your full blocks you need to cut in the edges, this can be completed either using a 2 stroke brick saw or a block splitter. These can be hired from your local hire shop. Using a straight edge or string line mark the width of the border using a block as a guide and mark a line onto the full block

Remove the marked block and place on the block splitter lining up the marks with the blade of the splitter

With a sharp pull down the block splitter will cut the block

Alternatively you can use a 2 stroke brick cutter with a diamond blade, this can be very noisy and dusty so make sure you wear a dust mask and ear protectors

Finishing off
Kiln dried sand is brushed over the entire area making sure all the joints are full to the top.

The vibrating plate is run over the total area 2 to 3 times to ensure the blocks are fully bedded into place

Your new drive or patio is finished and ready for use

Close up detail of the straight border to the edge of the block paving

Curved border with edging detail

This entry was posted on Sunday, November 13th, 2005 at 5:13 pm and is filed under Laying your own block paving. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.