Massetto Caldo MGN

The Massetto Caldo MGN lime-cocciopesto screed is the result of years of research, experimentation and testing, both in the laboratory and on-site, in order to reproduce and, if possible, improve the historic original.

Tests were carried out by CMR Laboratories in Italy to evaluate its performance in comparison to a sand-cement floor. Specimens of lime-cocciopesto and cement screeds were prepared and applied to the same underfloor heating system, and surface heat flow measurements have been undertaken on each.

A 17 mm diameter hydraulic pipe circuit was fastened onto a 1000 x 1200 x 30 mm expanded polystyrene (EPS) panel. Above this the following floor samples were laid out:

• An everyday sand-cement screed, in 40 mm thickness above the pipes, with a bulk density of 1800-1900 kg/m³,
• A Massetto Caldo MGN lime-cocciopesto screed, in 40 mm thickness above the pipes.

Both floor samples were left to mature for 28 days before taking any measurements. All samples were fed through a boiler that kept circulating the water at 32°C temperature.

Thermal flow measurements have been carried via thermo-flow sensors placed onto the surface of the floors, in-between adjacent pipes of the hydraulic circuit. The sensors have been connected to an automatic data acquisition system, which was taking readings at a 1 minute interval.

The above graph compares the surface heat flow generated by the two different floors. We can see how the cocciopesto floor heats up faster (red line), having a steeper curve than an equivalent concrete floor (blue line). Moreover, it steadily outputs by about 16% more heat than a similar concrete floor.

This indicates that a lime-cocciopesto screed:

• Heats up the living space faster, and
• Maintains the ambient temperature at a lower water temperature, using less energy than a comparable cement floor.