Guide · East Sussex · BN7
Lewes Microcement basement floors — cost, spec and build programme
For Lewes refurb clients, microcement basement floors sits at the intersection of two things they've usually already tried: the tile-and-grout route (grout-line fatigue) and full-slab stone (cost). microcement basement floors solves both — one continuous mineral surface at roughly a third of the stone-and-fixings price. The Lewes catchment we work across covers BN7, BN8 — reached via the A27 / A26, 15 min from brighton via the a27. Nearby coverage includes Ringmer (2 mi), Kingston near Lewes (2 mi), Firle (5 mi). Site conditions matter here: chalk substrate — dry, stable, easy to prime. That shapes the primer and sealer specification below, not just the visible finish.
Substrate diagnosis before we quote
Basement conversions carry the highest failure risk for any floor finish because of upward moisture pressure. Microcement over a properly tanked and drained basement floor is fine; over a damp slab it will lift within a year. The substrate diagnosis matters more than the finish specification.
How to make it read as designed, not applied
Basements benefit from a lighter microcement tone than the upstairs floor — bounces light into low-ceiling spaces. Continue the colour up onto the plinth as a coved skirting for a smaller, more designed feel.
System specification
How the install actually runs
- Moisture testPre-start
Digital hygrometer readings across the slab — must be below 75% RH before any finish work.
- DPM if requiredDay 1–2
Two-part epoxy DPM applied where moisture exceeds threshold. 24-hour cure between coats.
- Base coatDay 3
Reinforced base coat with fibreglass mesh.
- Colour + sealerDay 4–7
Colour coats, then 3-coat polyurethane sealer.
Where installs go wrong
- ✕Applying without a moisture test — the finish debonds when moisture cycles.
- ✕Missing DPM on a marginal slab — hydrostatic pressure lifts the finish.
- ✕Ignoring the basement tanking guarantee — voids it and passes liability to the finish.
- ✕Wet-cured sealer trapping moisture — use a solvent-free polyurethane, not wax.
Working in Lewes
Common questions from Lewes clients
Other guides for Lewes
Microcement basement floors — other Sussex towns
Related products & services
The short version
For basement floors in Lewes: expect a £95–£170 per m² budget, a build programme of about 3–5 working days on site, and a survey-to-install window of 4–6 weeks. The finish is one continuous mineral surface — no joints, no trims, no visible transitions.