Screed types · checked 29 October 2026
Lime screed and limecrete floors
Breathable floors for old stone and solid-wall houses, and when they make sense.
- Free quote request
- One contractor rings you
- All 12 Leinster counties
Figures checked against each source on 29 October 2026. How we check
Lime screed is a screed made with natural hydraulic lime instead of cement. It's used with limecrete in older solid-wall houses, where the floor needs to let moisture move through it rather than trap it at the foot of the walls.
The Department's guidance on traditional buildings says vapour-permeable floors made with lime and hemp or expanded clay may suit buildings where a delicate moisture balance has to be kept. It also warns that digging out an old floor can undermine shallow foundations.
Who asks for it
Census 2022 counted 79,372 households in Leinster living in homes built before 1919, and 141,281 in homes built before 1946, out of 1,004,936.
Source: CSO Census 2022, table F2067. Checked 29 October 2026. Our sum of the 12 Leinster counties.
Those are the floors people ask about: a cottage being restored, a farmhouse extension where the old part has damp at the foot of the walls, a protected structure.
Why not just concrete
A modern floor is designed to be impermeable, and the Building Regulations imply new floors should be, the Department's guidance notes. In an old house that can move the moisture problem rather than solve it: moisture that used to evaporate through the floor can be trapped and pushed towards the walls, raising the risk of damage from rising damp.
Source: Department of the Environment, Heritage and Local Government, Energy Efficiency in Traditional Buildings (Advice Series) (2010). Checked 29 October 2026.
How the floor is built
- Test pits by the walls.GreenSpec recommends two or three test pits first, because digging deeper than the foundations can destabilise the building.
- Dig out and level.Then a breathable geotextile.
- Insulating aggregate.Loose-laid foamed glass or expanded clay. Tŷ-Mawr's system uses at least 150 mm of foamed glass gravel.
- Geotextile, then the limecrete slab.Natural hydraulic lime with aggregate. Tŷ-Mawr specifies at least 100 mm, with screed fibres in the mix.
- Underfloor heating and lime screed.GreenSpec says the slab is usually left about three weeks before heating pipes go on, covered with a lime mortar screed.
- A breathable floor finish.GreenSpec advises against glazed ceramic tiles, cementitious adhesives and grout, and rubber carpet underlay.
Sources: GreenSpec, Limecrete floors for old buildings; Tŷ-Mawr, What is the Sublime floor (22 March 2024). Checked 29 October 2026.
The full build-up, with insulation values and a section drawing, is in our limecrete floor guide.
Radon and planning
Where a radon barrier is needed, the case for a breathable floor is less compelling, the Department's guidance says. GreenSpec notes a membrane will very likely be needed for radon. Check the EPA's radon map for your area before choosing.
In a protected structure, lifting or relaying a floor is likely to need planning permission. Talk to the planning authority before work starts. Decorative tiles, brick, wood block or stone flags shouldn't be covered over.
Sources: Department of the Environment, Heritage and Local Government, Energy Efficiency in Traditional Buildings (Advice Series) (2010); GreenSpec, Limecrete floors for old buildings; EPA, Radon advice for builders. Checked 29 October 2026.
What to send the contractor
- Photos of the existing floor and the foot of the walls
- Whether the house is a protected structure
- The floor area and any heating plans
- What floor finish you want on top
- Any damp history
Questions people ask
What is lime screed?
A screed made with natural hydraulic lime instead of cement, laid over a limecrete slab or underfloor heating in older solid-wall houses.
Is limecrete better than concrete in an old house?
Not always. The Department's guidance says lime floors may suit buildings with a delicate moisture balance, but a radon barrier weakens the case, and the Building Regulations imply new floors should be impermeable.
Can you have underfloor heating in a limecrete floor?
Yes. GreenSpec says the pipes go on the cured slab, usually after about three weeks, and are covered with a lime mortar screed.
Do I need planning permission to replace the floor?
In a protected structure, lifting or relaying a floor is likely to need it. Consult the planning authority first.
Sources (3)
Prices and facts on this page were checked against these published pages. We are not connected to these businesses.
- Department of the Environment, Heritage and Local Government, Energy Efficiency in Traditional Buildings (Advice Series): buildingsofireland.ie
- GreenSpec, Limecrete floors for old buildings: greenspec.co.uk
- Tŷ-Mawr, What is the Sublime floor: lime.org.uk
Get your floor priced
Four taps about the job and one screeding contractor who covers your county rings you. Or call 087 162 1846, lines open 8am to 8pm.