Yes when the existing slab is sound, you can pour a new layer of self-levelling concrete (self-levelling screed) over old concrete. This polymer-modified mix flows into low spots, then hardens into a smooth, flat surface. The big benefits are speed and finish: it creates an ideal base for tiles, wood or vinyl and often cures faster than traditional screeds. Because it can be applied very thinly (often a few millimetres), you can avoid breaking out the old slab. Done in the right conditions, it’s cost-effective, durable, and improves heat transfer for underfloor heating.
When it’s a good idea (and when it isn’t)
An overlay works well when the slab is stable and mostly intact ideal for minor cracks, shallow dips, or worn finishes. It can go over concrete, plywood, or tile if the surface is sound.
Avoid overlaying if you have major cracking, heave, movement, subsidence, persistent damp, or water damage. Covering these problems can lead to failure later those issues need repair or replacement first. LMA’s surveyors check every site and will tell you honestly if grinding, traditional screed, or deeper repairs are the better option.
Preparation (this is what makes it last)
- Clean completely: remove dust, grease, paint, adhesive residues.
- Repair defects: fill cracks, holes and spalled areas flush.
- Create a mechanical key: grind/scarify very smooth or power-floated concrete.
- Vacuum and prime: remove dust and apply the manufacturer-recommended primer to seal pores and improve adhesion.
Application basics
Mix 20–25kg bags to the correct ratio and pour quickly (it sets fast). Guide with a gauge rake, then use a spiked roller to release air. Typical thickness is 2–5mm (vs ~35–50mm for traditional). Many products are walkable in 24–48 hours, then ready for floor finishes once fully cured.
Cost and next steps
DIY materials for a small room may be a few hundred pounds; professional installs vary, with London often higher (some sources cite ~£10–£12/m² labour for basic levelling). A free survey is the best way to price it accurately LMA measures, advises, and quotes clearly so you get a flat floor that performs properly long-term.
Ready to level up? If your concrete floor is old, uneven or just not quite right, let LMA bring it back to perfect alignment. We offer fast surveys, honest advice, and prompt quoting. Contact us today for a friendly, no-obligation consultation – and rest easy knowing your floor is in capable, experienced hands.