Digging down to this depth over the whole area of a patio can leave you with a big pile of soil. The ecological option is to use this soil elsewhere in the garden rather than taking it off to the tip, from where it may end up in a landfill site.

Landscape contractors and builders usually use mortar as a ‘bed’ for paving, fixing the individual units in place. They seal the surface by using more mortar to backfill the joints between slabs. The resulting paving is rigid and strong. Brick and stone were traditionally laid in this way.

Many DIY handbooks show paving laid on to dabs of mortar, usually one at each corner and one in the centre. This is generally considered bad practice as it leaves a high proportion of the slab unsupported and liable to cracking. A continuous bed of mortar under each slab is better.

Compacted sand has recently become more popular as a bedding layer. The paving can be laid on to this, and joints backfilled with sand. When compacted and vibrated together, this combination is strong yet flexible, making it suitable for drives and parking areas. In general, smaller and thicker blocks or slabs are better for this kind of application. The larger and thinner the slabs, the more likely they are to crack.

Sand-bedded paving needs a solid edge, without which the bedding material will wash away. Solid edges can be built in mortar-bedded paving on a concrete foundation or supported by poured concrete ‘haunching’ – a continuous strip of concrete just below the soil surface. Metal strips are increasingly common, too.

Paving laid on sand needs no mortar grouting or jointing, but other methods do. Even if you use high-quality slabs, their appearance can be wrecked if grouting is applied poorly, or they are laid in an unsuitable pattern. Remember that mortar can be dyed or coloured to suit the slabs.

As for patterns, joints running along the length of a pathway will give a sense of direction; joints crossways will slow this sense of movement. Some materials do not have a unit-based pattern. Complex paving patterns should be executed in smaller units rather than by cutting larger slabs. This keeps the paving pattern simple and restful on the eye, and makes the material cheaper and easier to lay.

ess natural but also cheap is concrete in its pre-cast form

Best garden paving materials

One of the cheapest materials for hard landscaping is gravel, in which there has been a resurgence in interest. As a porous surface, it allows water to sink into the ground beneath – an option preferable to the non-porous surfaces used for growing numbers of paved front gardens, which create rainwater run-off that increases the risk of flooding.

Aside from loose gravel, aggregates can now also be bound with resin, so they look like gravel but are solid and weed-free. These materials can be laid to any shape or form.

Less natural but also cheap is concrete in its pre-cast form. Many concrete slabs are designed to imitate stone. Other mass-produced concretes include aggregates that give the finished slabs a more interesting texture.

© Richard Bloom

The costs of concrete paving rise dramatically when concrete is poured on site. Concrete itself is not necessarily expensive, but the work in creating moulds or formwork can be pricey. Moreover, it is not an environmentally friendly material to produce.

Stone is always popular, and expensive. If you want to use imported stone in your garden, it’s worth bearing in mind certain ethical issues. Some stone suppliers obtain materials from India and China, where some quarries have been accused of using child labour. There are also practical problems for British gardeners. Some imported paving slabs aren’t fully hardy in UK conditions. Water-absorbent materials, for example, may crack in freezing conditions. Check the provenance of any stone paving before you buy.

One paving material often prone to frost damage is brick. Most house bricks will absorb moisture and shatter in freezing temperatures. Instead, make sure you lay paving bricks, which are so dense that they will repel most water.

 

Drainage and paving

Paving needs to drain water effectively, or puddles will form on it. Slabs are usually laid to a ‘fall’ or gradient, a normally imperceptible 1:60 or 1:100 slope. When laying slabs against a building, paving must slope away from it, ensuring that there is no water penetration. Be aware that solid paving must not breach the damp course and should be 15-20cm below the internal floor level. In older properties, make sure the level of the paving is below any air bricks.

Where gardens slope towards the house, it is important to remove enough soil to create a sloping surface that falls away from it. Always create drainage gradients that fall away from the house or any other building. The subsequent drainage or holding of this surface run-off should also be a major consideration. Drains can also run along the threshold of the house. These are covered by open grilles and will carry excess water away from the house, especially during periods of heavy rainfall.

Garden paving inspiration

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