This lengthy post details our view on how to lay block paving for patios, paths and drives primarily in terms of construction for an English country garden.
As described before, construct the sub-base with the ground conditions in mind. Lay a fabric membrane underneath in clay or waterlogged conditions and then compact this with suitable machinery passing over the whole area 5 or 6 times.
Next, construct a frame of linear paving blocks around the area to be paved; which should be either laid long-ways or end-on (stretcher or header). This can be seen in the image (to the right) between the wall and the main block paving pattern.
The idea is to make a visual impact with the edging effect and to also cement these edge paving blocks down to retain the rest of the paving blocks that will be simply laid on a sand bed.
So, mix your cement mix ratio to 4(or 5)-to-1 course sharp sand/cement – so as it is not too wet in the mixer and slightly crumbling as it turns. Please make sure that you get this right because it makes all the difference when laying the paving blocks!
Set the brick line up for the first stretch of edgings – checking that everything is correct. Ideally a 50 mm bed is best under the paving blocks, thus a barrow of mix will lay 2 or 3 M of edgings.
Spread the cement mix along the line, making sure that you are getting the depth roughly right and by using the flat end of a small cold chisel tap down the paving block to the line; a small level will help as well.
Lay the next paving block and so on… this is where the correct mix is important – if too wet then laying the next paving block will disturb the previous paving block.
Lay the whole perimeter like this, cutting-in on the corners and around features, then using a small pointing trowel, smooth a fillet of cement all around the outside of your edgings halfway up the paving blocks. This is known as haunching and will lock the whole area in place.
Usually the next day the main area can be laid.
Now screed inside your area with course sharp sand making sure that you get the depth right by eye. You can use the back of a metal rake or a loop (tarmacing tool). Then compact down with a vibrating compactor plate (See ‘Tools Needed‘ section).
Now we come to the tricky part and it needs a degree of skill and concentration. The final screed level needs to be very good otherwise discrepancies will reflect through to the finished block paving.
Long lengths of straight metal or wood are perfect for making a screeding bar – the idea is to efficiently prepare a large area by dragging the bar across your compacted sand, adding some more and taking away as required. Clearing excess away helps as it mounds up.
Before you do this however, screed a margin inside your edging blocks using a long metal level and a spare block -making sure the block sits approximately 5 mm proud. of the edging paving blocks – this is important; the main area will settle on the sand base once the compaction plate is put over it.
As always, stretching a brick line across the block paving edgings at certain points and checking the clearance under the line will nail any mistakes on the screed.
Lay your paving blocks as per the preferred pattern butting them together carefully. It is prudent to set up a line that picks up the bond in the pattern and so will stop it wandering. Keep off the prep, walk on planks on the newly laid paving blocks and watch for creep along the laying edge from foot traffic.
When all the paving blocks have been in-filled, subsequently then is the cutting-in along the margins. This process is time consuming and difficult, but just as per pointing work, will make all the difference if well done.
Use an angle grinder and a good quality diamond disc (again see the ‘tools needed’ section of this site). When all cut in, run around the inside edge of the whole site with the angle grinder against the margin blocks. This has the effect of freeing-up any tight cutters, which will undoubtedly damage or split out when compacted down.
The next stage is to spread the entire area in kiln-dried block sand (needs a dry day). Brush all the sand in between the blocks and when done the final compaction can be completed with the vibrating compactor plate.
You now know how to lay block paving!
The final thing to do will be to then sit back and admire your new drive or patio completed to a good standard.
(c) Copyright 2013, Mark Cook, All Rights Reserved. Written For: gardenconstruction.net