Thermal and acoustic insulation for floors with the combination Isobet –
Thermofloor Silence (ISOBET-PLUS)

1. Thermal insulation for floors with Isobet

The thermal insulation of the floors will consist of a monolithic insulating ‘Isobet’ mortar layer, composed from a mixture of pure recycled EPS granules of 1 to 4 mm, and vermiculite with cement as a binding agent. The additional additives improve the thermal insulating value, homogeneity and mechanical properties.

After having been cleaned, the support floor is moistened and brushed with cement. If there exists the danger of rising damp, a polyethylene foil, the joints of which generously overlap, is placed onto the supporting floor.

‘Isobet’ is supplied in bags (approx. 130 litres) clearly labelled ‘Isobet’ and provided with multi-lingual directions for use. 25 kg of cement and water is added to the bag of ‘Isobet’ on site. The mixture is intensively mixed by means of a screed machine or large concrete mixer. The insulating mortar is always mixed per entire bag. The insulating mortar can also be mixed, supplied and pumped by means of a Mega-MaxiMixer.

The insulating mortar is spread to a thickness of ... cm (4 to 10 cm) in order to obtain a U value of ... W/m²K (please refer to table). This layer fully covers all pipes of electricity, heating and water supply.

After drying during 3 to 4 days the top floor or tiling is placed in a sand-cement bed.

The described insulation system carries a valid technical BUtgb (ATG 01/2450) approval.

Properties of Isobet :

• thermal conductivity : 0.075 W/mK (dry) – 0.085 W/mK (calculation value)
• compression strength: > 0.3 N/mm²
• weight by volume: + 240 kg/m³ (dry)
• fire resistance: A1 (NBN S 21-203) - MO (NF P 92-507)
• point load Ø 80 mm: > 550 kPa (NBN AND 12430)
• fatigue (15000 cycles up to 6 kN/m²) < 0.04 mm (WTCB TV 189 §8.2.3.)

2. Soundproofing foil and suspended top floor :

Up against the walls and around all vertical feedthroughs, the special double-sided laminated skirting board of canalised expanded polystyrene is tightly fitted. The skirting board is pre-processed so that a perfect angle between floor and wall can be formed. On top of the layer of Isobet a laminated foil of canalised expanded polystyrene (thickness 6,5 mm), Thermo-floor Silence, is applied. The foil strips overlap each other and the base of the skirting boards by 10 cm.

On top of the laminated EPS foil a reinforced suspended top floor or poured floor is placed in accordance with the T.V. notes of the BBRI. Minimum mass by volume of the top floor or poured floor: 1,600 kg/m³. During the placement of a top floor particular attention must be paid to prevent mechanical damage by the pumping equipment. During the placement of a poured floor particular attention must be paid to the perfect sealing of all joints.

Properties of Thermofloor Silence soundproofing foil:

• weight by volume : 15-20 kg/m³
• thermal conductivity : 0.036 W/mK
• resistance against fatigue: 15,000 cycles ( 2 kN/m² - 6 kN/m²)
• service temperature: from –30 to +70°C

Acoustic contact-sound insulation performance of the Isobet - Thermofloor Silence system:

According to NBN-SO1-400 contact-sound insulation for an empty top floor: category Ia. (test report WTCB THE 631X852, assessment according to NBN S01-007)

Thermal performance of an average floor construction with Isobet-Plus :