Once the site is prepared put five blobs of mortar on the ground where the first slab is to be laid – put one blob in each corner and one in the centre. It’s best to start at the corner of the patio.
Wet the back of the slab with some water applied with a large brush to make it easier to slide into place. Lower the slab carefully into place on top of the mortar. Tap it into position with a club hammer – have a piece of timber between the slab and the hammer so you don’t break it. Don’t stand on the slabs once you’ve laid them.
Repeat with a second slab and continue until you complete a row. Have 5mm wooden pegs as a spacer in the joints between the slabs (two to each edge on a medium or large slab) to make sure they are the same size for a neat finish. Use a spirit level across more than one slab to check the surface is flat and the fall is correct.
If you find a slab rocks, lift it out and re-lay it adding more mortar if necessary.
Continue to lay the slabs until the area is complete – keep checking and re-checking with the level as once the slabs have set in place you won’t be able to make any adjustment.
Wait at least 48 hours before walking on the slabs then remove the pegs. To fill the joints, mix a dry mortar (three parts sharp sand to one part concrete) and carefully brush it into the joints. Push it down with a trowel and add more mortar. There will be gaps that need filling, so you may need to do this several times.
Brush away all the mortar from the slabs. You need to do this thoroughly otherwise you will have a layer of mortar over the top surface of the slab. Once this is done, use a watering can with a rose attachment to lightly wet the whole surface.
Finish off the perimeter with a moist mortar mix, or use edging stones. Allow to dry for a few more days before using your patio.