Alongside a barbecue, a patio is an essential for a relaxed summer of outdoor entertainment. A patio, of course, is simply a level area of outdoor paving that usually abuts the house.
Concrete slabs (aka flagstones) are available in a massive range of colours and surface finishes and can be laid in a variety of different patterns, so no two patios need to be alike. And constructing a small patio is certainly a DIY favourite. Have a look at the video in the ‘how to’ section of this website before starting.
The key steps to success are ensuring that the slabs are properly supported (rocking chairs – good, but rocking slabs- not so good!) and that they are laid with a slight drop away from the house (typically 1 in 40, or 25mm per metre)
Decide on what size slabs you want and then mark up the area for the patio (usually based on a multiple of the slab size). If you want a complicated pattern, it’s well worth drawing it up to scale on squared paper, or even laying out the slabs on the ground to make sure they fit together, before you start work.
Dig out an area slightly larger than the patio to the required depth (enough for any sub-base plus the bedding layer and the slabs themselves). If the soil is firm, just compact it before adding the bedding layer, or otherwise consider using some sub-base material (available bagged from builders merchants) and compacting that in place before the next step. Hire in a vibrating compactor plate if needed.
The slabs should be bedded in about 25 -40mm of a weak mix of sand and about 10% cement, these are available as premixed bagged products to save on-site mixing. Just before placing the slabs, wet both the top surface of the bedding layer and the underside of the slabs with a fine spray of clean water. Tap the slabs into place with repeated gentle taps from a rubber or wooden hammer until they are level (check with a taut string line and/or a straight edge).
It’s important that the slabs are firmly supported over their entire surface or they will rock. Wait a couple of days (until the bedding layer has started to harden and pint the gaps between the slabs using a premixed bagged mortar, trying very hard not to get it on the surface of the slabs), brush off any loose material, wet with clean water and finish off the pointing, then cover with polythene sheeting for a day or so. Job done!