Retaining wall builders
Brick and block retaining walls for sloping gardens, driveways and level changes, built with footings and drainage.
What a retaining wall has to do
A retaining wall holds back soil so that ground on one side can sit higher than the other. Retaining walls and steps are part of our hardscaping service, and they are what turn a sloping garden into level terraces, or let a driveway be cut into a bank. Unlike a garden wall, a retaining wall is pushed on constantly by soil and by water in that soil, so the design matters far more.
How we build them
Every retaining wall starts with a footing sized for the height of the wall and the soil behind it. Masonry walls are usually built in brick, block or brick-faced block, often with steel reinforcement in the footing and hollow blocks filled with concrete. Behind the wall, free-draining stone and a perforated pipe or weep holes let water out, because waterlogged soil pushes much harder than dry soil. The face is finished in a brick to suit the garden or house.
Taller walls, walls carrying a driveway or building above them, and walls on a boundary may need an engineer's design. King post walls, with steel posts set in concrete and panels slotted between them, are another option where space or access is tight.
Why retaining walls fail
A wall that is leaning has usually been built without a big enough footing, or without drainage, so water pressure has pushed it over time. Cracking often follows the same movement. White deposits on the face are efflorescence: salts carried through the wall by water draining from the soil behind it, which is a sign the wall needs a waterproof membrane or better drainage on the back face.
Planning and neighbours
Low garden retaining walls rarely need planning permission, but a wall that raises ground levels significantly, sits beside a road or forms part of a boundary can. Where a retaining wall is on or near the boundary, it is worth agreeing the work with the neighbour first, and the Party Wall Act can apply if excavation comes close to their foundations. Soil is heavy and the consequences of a collapse are serious, so on taller walls an engineer's design is money well spent.
Retaining walls in sloping gardens
Breaking a steep slope into two or three lower walls is usually safer and better looking than one tall one, and it gives planting space on each terrace. Steps between levels can be built into the same job. Our retaining wall guide and retaining wall types guide go into the options in more depth.
Questions people ask
- Why is my retaining wall leaning?
- Usually because water has built up behind it or the footing was too small for the soil it holds. A leaning retaining wall should be looked at before it gets worse.
- Why is my retaining wall turning white?
- That is efflorescence: salts carried through the wall by water from the soil behind. Better drainage and a membrane on the back face usually stop it.
- Why is my retaining wall cracking?
- Cracks often come from the wall moving under soil and water pressure, or from a weak footing. The cause needs fixing as well as the crack.
- What is a retaining wall made of?
- Common choices are brick, concrete block, brick-faced block, reinforced concrete, steel king posts with panels, and timber sleepers for low walls. We build in brick and block.
- What affects retaining wall cost?
- Height, length, the footing and reinforcement needed, drainage, the facing brick, access and how much soil has to be moved. We give a free estimate after a site visit.
Related: hardscaping · retaining wall guide · retaining wall types · garden landscaping · garden walls.