Concrete Sidewalks and Walkways

When a sidewalk or a garden path has broken along its whole length, patching rarely gives a good result. The new pieces stand out, and the old ones around them keep failing. One option then is to relay the whole stretch in concrete: one continuous surface, with no slabs rocking and no gaps for weeds.

Concrete or slabs?

Concrete goes down as one single surface, follows awkward shapes and manholeInspection pitA small chamber in the ground with a cover, where drain or rainwater pipes meet and can be checked and cleared. covers easily, and doesn't have lots of joints that can open up. On the other hand it looks plainer, and when it cracksCrackA split or gap in render, concrete, a wall, a coating or wood. Fine cracks are usually only on the surface; ones that grow, keep reopening or run diagonally need attention., the crack shows. Slabs and stone look warmer and can be repaired piece by piece, but their joints need looking after. The choice depends on how the space is used, the style of the house and, for a sidewalk, on what the municipality requires.

The steps

1. Clearing. Weeds, moss and anything loose or crumbling come out, so the new concrete sits on a sound base.
2. Levels and falls. Before the concrete is poured, it's decided where the water will run, usually towards the street or a drain, and how the new surface will meet the kerbKerbThe row of stone or concrete along the edge of a sidewalk, which separates it from the road and holds the paving in place., the wall and the entrances.
3. Pouring and levelling. The concrete is spread along the whole length and levelled with a straightedge. Around manhole covers the surface has to come up to the same height, so no step is left. Depending on thickness and use, steel meshReinforcement meshA mesh or fabric, usually glass fibre or polyester, set into render, a coating or liquid waterproofing to hold it together and stop cracks from opening. may also go into the concrete.
4. Protection and curingConcrete curingLooking after fresh concrete in its first days: keeping people off it and stopping it from drying out too fast, so it hardens properly and doesn't crack.. Fresh concrete has to be kept off while it sets, and it's best if it doesn't dry out too fast in the sun, because then it cracks more easily.
5. Finishing. Once it has dried properly, the surface can be left as it is or painted.

On one sidewalk covered in moss and broken pieces, new concrete was laid from the kerb to the wall and around the manhole cover. A board resting on bricks blocked the way while the concrete set, so nobody would step on it. Once it had dried, the surface was painted grey and the base of the wall white, and the sidewalk became one clean, continuous stretch along its whole length.

Painting

Paint gives an even look and hides the difference in shade between new and old concrete. But it's a thin layer that wears under foot traffic, so at some point it needs renewing. Ask whether the paint is made for outdoor floors and whether it's slip-resistantSlip-resistant surfaceA floor, tile or paint with a textured finish that doesn't get slippery easily when wet. It's needed on balconies, courtyards, steps and around showers., because a smooth painted surface can be slippery when wet.

Before you start

The sidewalk in front of the house is a public space. In many municipalities work on it needs a permit or has to follow set specifications for materials, colours and levels. It's worth asking your municipality before the work starts.

Take care with the utility covers too (water, electricity, telephone). They must stay clear, flush with the surface, and able to open.

What to ask

• Will the old floor be broken up and removed, or will the concrete go on top of it?
• Which way will the water run?
• How will the fresh concrete be protected, and when can it be walked on?
• What paint will be used, and is it slippery when wet?