Insulating Above A Groundbearing Slab

“…when installed with a screed is ideal for underfloor heating…”

Putting floor insulation on top of a slab shields the slab’s thermal mass from the building envelope which makes the building easier to heat.
Insulating a groundbearing floor above the slab excludes the thermal mass of the slab from the building envelope, making the building more responsive to heating: the construction is suited to buildings, which are intermittently heated.

This construction is compatible with masonry and timber framed wall constructions and, when installed with a screed, is ideal for underfloor heating.

The properties of Ballytherm insulation match those required for this application: it is robust and moisture resistant, whilst its low thermal conductivity minimises the thickness of insulation within the floor construction.

The necessary thickness of the Ballytherm Insulation can be worked out from the following Table 5.

Table 5

Further Advice & Information

For more information about Ballytherm products, technical advice, or guidance on the suitability of our products for your project, contact us at + 353 (0)49 95 27000,, email us at or use our contact form.

Floor Insulation

Design Guidance