What is a subfloor?

Greenhus project in Co Cork

It is the flat structural surface that goes on top of your foundations.

This often includes hardcore (stone filling material), then blinding (sand or weak concrete to provide a level working surface), radon barrier with sumps (where sumps are necessary), and then a thick (often 100 to 150mm reinforced with steel mesh) concrete slab to support the weight above.


Written by Astrid Madsen

Astrid Madsen is the editor of the SelfBuild magazine. She previously held the same role in an Irish trade publication, before that she worked at the National Standards Authority of Ireland. She graduated with a BA in Urban Studies from Columbia University in New York and holds an MBA from the Instituto de Estudios Bursatiles in Madrid. France of origin, she now lives in Portarlington, County Laois, where she's taken on the task of renovating a listed building! Email astrid.madsen@selfbuild.ie

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Modern bungalow in County Donegal