Basically this article will act as a guide for you to outline the steps to take to successfully lay your own block paved driveway.
So lets look at the process:
Firstly You will need to remove your existing driveway, this could be either concrete, tarmac or concrete flags. To make life easy hire a mini digger from a local tool hire company and you will clear this stage in a day. If you want to however this can be done by hand but will take much longer to do!
The minimum amount you need to remove from the top of your existing driveway is 250mm (10″) to allow for 150mm (6″) of hardcore, 50mm (2″) of sand/gravel and 50mm (2″) for your block paving.
If the ground underneath your driveway is particularly soft you will need to remove more earth or clay and replace with additional hardcore which will need to be compacted in layers of no more than 75mm – 100mm at a time.
Remember that if the driveway butts up to your house or garage building, the finished level of your drive must remain 150mm (6″) below damp-proof course.
Step Two Set up your level line. You will need to knock 2 timber or steel pins into the ground, one at the house end of the driveway and the other at the pavement side. Next, attach a tight builder’s nylon line at what will be the finished height of your block paving, this line should be approx 10mm higher than the pavement and 150mm lower than the damp proof course to allow for final compaction of the block paving.
Hold your level on this line at the house end and either raise or lower it until it is level, if you have a gap under the level and the line on the end facing the pavement, then you have the correct direction of fall in the driveway. When you are satisfied with the height and fall of the line, wrap some tape around the pegs to the underside of your line, this will save having to go through the same process again if the line is moved for any reason.
Make sure the line is tight as you don’t want any sag in your line, this will give a false reading with your levels which could result in your finished driveway holding water.
If your driveway is falling towards the house, then simply reverse the fall and levels from the pavement towards an existing rain water gully. If this isn’t possible, you will have to install drainage channels along the front of the property. Water should then be directed into a soak-a-way within your garden area.
Step Three Place a geotextile layer (weed control fabric) on top of the subsoil to the total area of your driveway. This eliminates mixing of the sub soil or clay and the hardcore yet still allows water to flow away freely.
Hold this in place using a few bricks or blocks and keep it tight whilst adding the hardcore.
Step Four Spread your hardcore to the total area of your driveway and ensure it is to a depth of 150mm (6″). It now needs to be compacted to form a solid base for your blocks to be laid upon. This is achieved using a vibrating plate compactor or vibrating roller.
Step Five All areas of your block paving must be surrounded by a solid edge to prevent the blocks and the sand on which they are laid from creeping.
Use 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 grit sand to 1 part cement and hauched front and back to hold in place.
Step Six Spread 50mm (2″) of course grit sand to the entire area approx. 20mm higher than the finished height to allow for compacting. Level the sand with a shovel roughly to the correct height continue this over the total area until you have covered all the hardcore.
This now needs to be compacted, go over it 2 – 3 times. Continue until you don’t leave any marks on the sand when you walk over it.
There are 2 methods you can employ as the bed for block paving, one, you have fully compacted sand making the sub base and the laying coarse much firmer, achieving a much flatter surface. To achieve this you need your sand approx 10 – 15mm higher than the finished screeding height, this surplus sand is screeded off to the correct height and then you lay your block paving.
The other way is to have 2/3 compacted sand and a third loose sand which you screed to the desired height, this is easier to screed but can result in soft spots.
Step Seven To establish the finished height of your block paving use a block as a guide and push it down into the sand until it is 5mm higher than the finished height to allow for the final compacting once all the block paving is laid.
The finished level of block paving should be 150mm below the house D.P.C. Level
Step Eight You need a flat bed for your pavers to lay on, to do this you can use 18mm galvanised steel electrical conduit, they are not expensive but are better than using timber because the piece of timber or aluminum used to screed the sand will slide along them much easier.
Using a tight string line to get the screeding rails to the correct finished height prior to screeding the sand, check for level or falling towards any drains, a 1:60 fall is required, that’s 1″ in height to 60″ in length minimum fall to ensure any surface water drains into your drainage system or soak-a-way.
Once the screeding rails are in place begin to screed the sand to the correct height. When the screeding is finished remove the steel screeding rails and fill the gap with grit sand sand using a steel trowel to give a flat finish.
Step Nine The next step is to start laying the block paving, the full blocks are laid first to a straight line using a string line and then keep laying the blocks until the total area of your drive is completed. The block can be laid either square to the house or on a 45 degree angle.
When you complete the laying of your full blocks you then need to cut in the borders, you can cut bricks using a block splitter. Holding the brick in place over the border, looking from above mark a line onto the full block on each side where it meets the border, draw a line between these 2 points and cut off the surplus using the block splitter, then simply put the cut block in place.
Step Ten When all blocks are in place, brush down the driveway to remove any broken pieces of block or debris to ensure they don’t get down the joints between the block paving.
Brush kiln dried sand over the entire area making sure all the joints are full to the top. Then give them a compacting with the plate compactor, leave surplus sand on top of the the driveway so when the vibrating plate passes over it, it will spread about filling any joints which may require more sand.
Run over the total area 2 to 3 times to ensure the blocks are fully bedded into place, any surplus kiln dried sand should then be swept away.
Your Block Paving Driveway is now completed and ready for you to use. Give yourself a pat on the back and treat yourself to nice cup of tea!