Thicknesses of Fibrexpan® to be used depending on the thickness of the reinforced concrete slab and the desired surface transmission coefficient U, taking into account the surface resistances, for a downward flow and a wall facing an unheated closed room.
(Rs = 0,21 m2.K/W) :
reinforced concrete: λ= 2 W/m.K
Fibrexpan® : λ = 0,038 W/m.K
Thermal protection of concrete slabs
Fibrexpan® is a spray-on fibrous coating for thermal insulation of surfaces not exposed to the weather on concrete structures.
Fibrexpan® is ACERMI-certified with respect to conductivity and thermal resistance values
ACERMI is the result of a dual commitment:
• That of the manufacturer who undertakes to put in place a quality system and the necessary means to control the quality of its products and the maintenance of this quality over time.
• That of the certifier, an independent, competent and recognised body, whose role is to guarantee the truthfulness of the announced characteristics and to re-evaluate them periodically.
ACERMI certification, which guarantees the thermal properties of the product when it leaves the factory, is supplemented by a Unified Technical Document (DTU 27.1).
This specific DTU 27.1 document is used to validate:
• Application of Fibrexpan® up to a thickness of 240 mm on a concrete support, with no intermediate reinforcement
Conditions of implementation regarding Fibrexpan®
Precautions to be taken in order to achieve high-quality spraying.
DTU 27.1 also defines a self-checking method, which is essential to justify that the performance guaranteed by ACERMI certification, when leaving the factory, is reproduced on
the worksite. The results of the self-checks are reported in the worksheet.
The objectives of the worksite datasheet are to:
• Mark out the quantity of insulation sprayed,
• Ensure traceability from the finished product in bulk, leaving the factory, to the finished product, applied on site (part 2 of the sheet),
• Guarantee the thermal performance according to an installed density and thickness per machine and per thickness.
The form is produced in triplicate:
• One copy is kept by the spray application technician,
• One copy is kept by the principal,
• Once copy is kept by the contracting authority.
These supporting documents must be kept for at least 10 years and according to the regulations in force.
A form must be filled in for each machine and each spraying thickness (i.e. for each setting).
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Techniques for using Fibrexpan® for the thermal protection of concrete slabs
The spraying technique, also known as flocking, consists in applying Fibrexpan® fibres under pressure using special machines. The sprayed thickness will be defined according to the desired thermal insulation rating (R).
The spraying machine generally comprises a feed hopper, a carding device, a blowing device (fan, turbine or blower), a hose for conveying the mixture to be sprayed. A spray gun and water.
The product is fed through a hose to a spray gun using compressed air. Water-fed nozzles are placed around the hose outlet to wet the product before it is sprayed onto the substrate.
The thickness of the spray-on coating will vary according to the thickness of the reinforced concrete slab and the desired thermal resistance.
First, a bonding agent must be applied.
Projiso Fixo B® is used for concrete supports.
The coating will be finished with Projiso Fixo Dur® or Sidairless®
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