Breathable Limecrete Floor Replacement in Brighton & Hove

What a Limecrete Floor Is

A limecrete floor is a solid ground floor built from vapour-permeable materials. In the build-up we install, a compacted layer of foamed glass gravel forms the insulating, free-draining base, and a limecrete screed — natural hydraulic lime mixed with an appropriate aggregate — forms the floor itself. Breathable finishes complete the floor: a lime-based screed finish, tiles bedded in lime, or a floating timber deck laid over the slab.

Foamed glass gravel is manufactured from recycled glass, expanded into lightweight, closed-cell granules. It will not rot, will not hold water in the way damp hard-core does, and its air-filled structure gives the floor its insulation while remaining permeable to water vapour.

The result is a solid floor that behaves the way a traditional solid floor was meant to behave: moisture rising from the ground passes through the build-up and evaporates, rather than being collected and held against the building.

Why Impermeable Concrete Slabs Trap Moisture

Most of the damp solid floors we are asked to look at in Brighton and Hove are not original. They are twentieth-century replacements: a damp-proof membrane, a dense cement screed, often laid over broken hard-core, installed on the understanding that sealing the ground out is the same as keeping the building dry.

In a modern building that build-up is legitimate. In a period property with solid walls — bungaroosh, soft brick, flint and lime mortar — it works against the building. Ground moisture that can no longer evaporate through the floor migrates sideways into the base of the walls, where it meets finishes and timbers with nowhere to give that moisture up.

The consequences are predictable and we see them repeatedly: persistent high moisture readings at wall bases, decaying skirting and joist ends, salts pushing through plaster just above the floor, and floors that feel cold underfoot because the moisture is held within the slab rather than passing through it. Replacing such a floor with another sealed concrete build-up reproduces the same problem on a new invoice.

The pattern is at its most damaging in bungaroosh construction, where the wall fabric depends on being able to dry in every direction. An impermeable floor laid hard against a bungaroosh wall removes one of those directions.

Diagnosis Before Specification

We do not replace a floor because it reads damp. We replace floors where the diagnosis shows the floor itself is the mechanism holding moisture in the building, and where a breathable build-up is the right response.

Our normal sequence is to:

1. 1Establish the floor construction — solid slab, suspended timber, or a hybrid of both, since many period properties here have been part-altered over the years
2. 2Identify what lies beneath and beside the slab, including the wall construction at floor level and the position of joists and services
3. 3Establish where the moisture is coming from: ground moisture, drainage defects, plumbing leaks, condensation or bridged damp-proofing
4. 4Check whether the walls are independently affected, because replacing a floor will not resolve moisture entering through a wall
5. 5Check the condition of any suspended timber that will remain, including joist ends built into the walls
6. 6Establish headroom, finished floor height, door positions and service runs, which govern the build-up that can be achieved
7. 7Set out in writing what the diagnosis supports, what will be replaced, and what falls outside this scope

Consent and Listed Buildings

In a listed building, replacing a ground floor can require listed building consent, particularly where historic floor fabric survives beneath later alterations. In conservation areas the position is usually more straightforward, but it should be established rather than assumed.

Where an original floor survives — brick paviors, stone flags or an early lime-ash floor — the first conversation is about whether replacement is justified at all. Where a twentieth-century concrete slab covers the original construction, its removal can reveal fabric worth reinstating rather than covering again.

We establish the consent position with the local authority before work begins, and we do not proceed on the assumption that a like-for-like replacement is automatically permitted.

The Replacement Process

Replacing a solid floor in an occupied period property is staged work. The sequencing is designed around keeping the building weathertight, the fabric supported and the moisture pathways respected.

The work follows a set sequence:

1. 1Confirm the specification: excavation depth, foamed glass build-up, screed thickness, finished floor height and the junction details with the walls
2. 2Break out the existing slab and remove it, together with any buried debris and wet fill, working with care around the exposed wall bases
3. 3Excavate to the required level and dispose of the arising
4. 4Repair wall fabric exposed at floor level where the excavation reveals defects, in lime mortars matched to the substrate
5. 5Lay and compact the foamed glass gravel in level lifts to the specified depth
6. 6Lay the limecrete screed, finished to level and protected while it cures
7. 7Allow the floor to cure and begin drying before finishes are applied
8. 8Reinstate the floor finish — breathable screed finish, tiles bedded in lime, or a floating timber deck — along with skirtings and perimeter details

Curing and Timescales

Limecrete gains strength differently from concrete. Hydraulic lime sets as it dries and then continues to carbonate — reacting with carbon dioxide in the air — over weeks and months. We do not rush that chemistry, because a floor finished too early is a floor that fails at the surface.

The timescale before finishes can be applied is governed by:

• The season, since damp coastal winters slow both carbonation and drying
• The thickness of the screed and the moisture held within the build-up
• The chosen finish, since tiles and floating timber decks each require a different moisture condition before they are laid

Underfloor Heating

A limecrete floor over foamed glass gravel can accommodate underfloor heating, and the combination is a comfortable one in a period property where a solid floor would otherwise feel cold underfoot.

We do not install underfloor heating. Our role is the floor itself and the build-up around it: where a client wants heating within the limecrete, we project-manage its integration by the appropriate heating engineers, so their pipework is coordinated into our specification, sequenced around the pour, and pressure-tested before the screed closes over it. The heating installation, its controls and its commissioning remain with the specialists who install them.

What We Price Against

We do not publish figures. A floor replacement is priced against what the diagnosis finds: the depth of the existing slab, what lies beneath it, the finished floor height the building allows, and the condition of the fabric exposed by the work.

The elements priced in a limecrete floor replacement are:

• The diagnostic survey and written specification
• Breakout and removal of the existing slab and fill
• Excavation and disposal of arising
• Repairs to wall fabric exposed at floor level, where required
• The foamed glass gravel base, laid and compacted
• The limecrete screed
• Breathable floor finishes and junction details
• Making good, skirtings and decorations affected by the work

Areas We Cover

We replace damp-trapping solid ground floors with breathable limecrete build-ups throughout Brighton, Hove and the East Sussex coast, in period terraces, Regency and Victorian semis and converted properties where an impermeable slab is compromising the fabric.

• Brighton
• Hove
• Portslade
• Southwick
• Shoreham-by-Sea
• Lewes
• Newhaven
• Seaford
• Eastbourne
• Peacehaven
• Saltdean
• Rottingdean