As demand grows for excellent energy performance, there has been increasing emphasis on providing thermal insulation to the underground structure of buildings.
As well as reducing heat loss into the ground, floor insulation also assists in satisfying requirements for thermal comfort. Floor temperatures should not differ from the heated room air temperature by more than +/- 3 degrees C, and condensation should be prevented both on the floor surface and inside the floor structure.
Ravago XPS thermal insulation products have proven performance in places exposed to damp conditions below ground.
When designing and selecting thermal insulation materials to be in direct and permanent contact with the floor slab beneath an entire building, ensure lasting and efficient operation by choosing the appropriate Ravago XPS product.
Using RAVATHERM XPS products for the thermal insulation of reinforced concrete slab foundations has the following advantages:
- long-lasting thermal protection, despite the permanent presence of moisture
- no ground water pollution
In determining the load bearing capacity of a floor structure containing a thermal insulation layer, under permanent and live loads, Design Compressive Strength value of the insulation should be used (DCS is the load that if applied as a UDL for 50 years then max compression 2%).
A structural engineer should be consulted on the final choice of the appropriate material, structure and construction.
Ravago XPS thermal insulation in the floor slab beneath the building should be laid only on precisely prepared and carefully compacted and smoothed substrate.
Ravago XPS thermal insulation products should be laid with joints offset, and staggered between layers directly onto a level smooth compacted sand bed or a thin blinding layer of concrete.
The boards can be cut to size with hot wire cutter, knife or small-tooth saw. Cut surfaces should allow the boards to be fitted tightly together.
PROTECTION OF INSULATION
When the thermal insulation boards are laid on top of the damp proofing membrane, they also provide mechanical protection during the construction phase. This role is particularly important during the installation of steel reinforcement in concrete.
Any gas membrane should be placed under the insulation and a DPM can be placed under the insulation - but a DPM/ vapour barrier /separating membrane should always be placed over the insulation below the concrete/screed.