Adding an edge to a patio can provide it with a neater, finished look. It may be edged to match the existing materials or with a different material to either provide contrast or to link to the house or the rest of the garden.

If you are edging an existing patio, you may want to use this opportunity to add a bit of extra space, which could be surfaced with gravel. In addition to giving you more room, the gravel can act as a subtle transition from a hard patio to the soft planted part of your garden.

Any edging material may be used, such as bricks, pavers, concrete blocks or cobbles as long as they are frost-resistant.

1. Prepare the Site

Mark out the edge around your patio based on the size of your edging material, using string and pegs or a sand guideline. Remove any turf from the strip. Dig a trench to the depth of your edging material plus 2.5 cm for the mortar. Level the soil along the strip using a rake and then spread an even layer of sand along the base.

2. Lay the Edging

Compact the base of the trench with the back of a garden rake, and then place a 2.5 cm (1 in) layer of mortar along the base to bed the edging material in. Place the edging into position, filling in the sides of the trench with more mortar. Make sure that you do not spill any mortar over the parts of the edging that will be visible.

Tap the brick, block or slab down firmly with a piece of timber or the handle of a trowel. Use a spirit level to check that the top of the unit is level. Continue laying your patio edge in this manner. Finish off the mortar in the sides of the trenches by smoothing it with a pointing trowel so it slopes away from the bricks.

Extending the Patio

If you want to extend your patio area to create a gravelled section, mark out the new area using string and pegs for straight edges or a sand guideline for curves. Dig out the site to a depth of 18 cm (7 in) and compact the base. If the patio runs next to a lawn, dig out an extra 2.5 cm (1 in) (to 20.5 cm or 8 in) so that the surface is below turf level. Apply a liquid weedkiller to the hole.

Add a suitable edging using the methods described in (1) and (2) above.

Add a 10 cm (4 in) layer of compacted hardcore, followed by 5 cm (2 in) of a sand and coarse gravel mix. Compact each layer with a roller. To suppress tap rooted weeds, lay down a sheet mulch, such as permeable polypropylene, fibrous matting or heavy duty polythene with holes punctured throughout. Take care to ensure that it is as flat as possible, and then secure the edges by pushing them into a V-shaped trench and covering them with soil. Any joins in the sheet should have a seam of at least 2 cm overlap and be secured in position with ground staples every 1 m.

Cover the new patio area with 2-3 cm (1 in) layer of gravel such as pea shingle. Apply the gravel in several stages, raking and rolling it to produce a slight camber for drainage. Water the gravel using a watering can fitted with a fine rose or dribble bar to help compaction and improve the path's appearance.