Cement garden

Terraces are like icebergs: what's underneath is more important than what's on top. Anna Pavord on the quest for a perfect patio

``The patio" is a term used by estate agents to describe any collection of paving stones that is loosely attached to a house. Builders like patios because they give an illusion of order to a new house. They push all the muck they should never be leaving behind into a raft around the back door and then drop concrete slabs on top of it as they retreat backwards off the site - usually for ever.

Gradually the forces of gravity try to make sense of the plastic sacks, copies of The Sun, solidified cement powder, off-cuts of rafters and fossilised sandwiches. The patio begins to heave like the sea in the Bay of Biscay.

This is the point at which the novice gardener usually moves in, fired with enthusiasm by articles on making the garden an extension of the living-room. There are visions of candlelit supper tables, parasols and loungers. The reality is stubbed toes, and chairs that never sit with four legs on the ground.

Patios are like icebergs. What is underneath is more important than what is on top. There is little you can do to disguise an erupting patio. However much you may try to persuade yourself otherwise, the only true solution is to lift off the top layer and sort out the substratum.

If you call in someone else to build or rebuild your sitting-out place, make clear specifications on a few key points. The foundation should be made of 100mm of hardcore, topped up with sand and shingle to give a smooth bed for the final layer of paving stones, bricks or whatever material you decide on. The finished level of the patio must be at least 150mm below the damp course. If this is impossible, plan for a gap of 75mm between terrace and house wall and fill it with hardcore topped with pebbles or gravel.

Drainage is another nightmare. Any water that collects on the patio must be persuaded to spill over the garden edge and not in through the kitchen door. House drains and air bricks must also be treated with caution, and not immured carelessly behind half a ton of concrete.

The texture of the finished terrace will have an important effect on the pleasure you get from the garden as a whole. Concrete is cheap but, unless used carefully, looks it. Colouring the concrete compounds, rather than alleviates, thedeficiencies of the material. A chequerboard of pink, grey and green slabs may seem an interesting idea on paper, but it is an uncompromising pattern to live with. Better to let the colour come from the plants and containers. These can change from season to season and will be shown off far better in a plain setting than against a psychedelic array of chemical dyes.

I would go for a neutral colour, but choose paving slabs with some surface texture. Manufacturers call them "riven" slabs. Although they do not weather like stone, they are far more pleasing to the eye than the flat, matt surfaces of the standard concrete slab.

Whatever material you use for paving a terrace, it should fit in with the other materials around it. Brick makes a satisfactory surface, not only because it is full of texture, but because it can be laid in so many different patterns. You could do a whole terrace in basket-weave or herringbone, or divide the space into squares with straight double lines of brick, infilling the spaces with bricks laid in a different pattern. They must be frost-proof. As a rough estimate, you will need 48 bricks of the old size for each square yard, if you lay them on edge (the best way), 32 if you lay them flat.

Timber decking has never caught on here in the same way as it has in the States where it is often used as a transition between house and garden. I have not tried it in my own garden, but the possibilities are intriguing. Wood is not as durable as concrete or brick, but it has a warm, pleasant texture and is more malleable than either of the others.

It is a good way of creating a flat space on sloping ground without all the expense of levelling or building up which a concrete terrace would demand on such a site. The deck can sit on a timber underpinning and the supports can easily be clothed with climbers which will then poke their noses in at the level of the decking. Wood gets slippery in wet weather, but there are anti-slither products available.

The amount of space that a patio takes up should bear some reasonable relationship to the size and shape of the garden as a whole. It is more common to make them too small than too big. You cannot relax in a space if you have to jump out of your chair every time someone else wants to get by.

We've just made a new sitting-out space, facing west, where the sun lasts longest in the evening. It's a little bit away from the house so there were no problems about drainage or damp courses. It is 18ft long by 12ft wide, with walls on two sides, a fence on the other and lawn in front. The stone walls dictated the proportions, but a ratio of three to two, length to breadth, often feels the most comfortable. Levelling the area was the biggest job, carting in soil from other parts of the garden, then raking it over and waiting for the verdict of the spirit level, which seemed viciously intent on prolonging the heavy labour.

We left the area to settle, killed the weeds, and then covered it with beach pebbles, which are rounded rather than sharp. Contractors would probably have recommended a layer of Terram or some similar plastic mesh material under the pebbles. This would have stopped the pebbles disappearing gradually into the earth, and would also have prevented weeds growing through. But I hate that kind of sterility. For the sake of self-seeding poppies and columbines, I'm happy to pull a few weeds now and again.

To edge the area that butted on to the lawn and make a barrier between pebbles and grass, we used old slate slips, the kind that used to be set round fireplaces. They are 3ft 6in long, 5in wide and about an-inch-and- a-half thick. We picked them up at a local salvage yard for pounds 3 each. Another slab of slate (5ft x 2ft), from a dairy that was being demolished, makes a table, set on top of an old mangle. A slab 5ft by 3ft would have been better, but you can't be choosy when you haunt demolition sites. The bodger's bench I wrote about last week in Cuttings completes the scene. Now I can't think how we ever did without it.