Flat roof insulation with EUROTHANE Bi3A on wooden bearing construction for roofs with limited drainage and partially bonded bituminous waterproofing with bituminous cold glue

The thermal insulation will be realised by a board of rigid Polyurethane foam (Eurothane Bi3A) with a core volume weight of ± 30 kg/m³.
The boards will be faced on both sides with bituminised glass fleece.
The boards are subject to a permanent quality control conducted by an acknowledged institute and will have a technical approval. The production of the insulation boards is certified according to the ISO 9001 : 2000 standards.
The declared thermal conductivity coefficient λ_D = 0,027 W/mK for thickness › 60 mm and 0,028 W/mK for thickness ≤ 60 mm.
Pressure resistance with 10 % deformation: > 120 kPa (1,2 kg/ cm²).
The dimensions of the boards are 1200 mm x 600 mm. The thickness varies in the longitudinal length. The fall will be 1/60 or 1/80.
The insulation boards are:
- either bonded completely on the vapour barrier by means of hot bitumen
- or mechanically fixed in the bearing structure with a minimum of 4 screws per panel. The correct amount of fixations will be defined on the basis of the quality of the fixations and the bearing structure and the wind load.
Preceding we place on the wooden underground:
- a partition layer of glass fleece or polyestermat
- an underlayer P150/16, reinforced bitumen with polyestermat, nailed to the underground
- a vapour control layer bonded with hot bonding or torch-on method.
The waterproofing is applied directly after the installation of the insulation. The bituminous waterproofing is fully bonded immediately after the installation of the insulation by means of an adapted bituminous cold glue and in compliance with the prescriptions given by the glue manufacturer. The compatibility of the cold glue with the PUR-boards will be shown by the glue manufacturer.
The necessity of a vapour control layer will be determined by a calculation or by the Technical Information 215 "HET PLATTE DAK" (the flat roof) of the WTCB. The specific guidelines incorporated in the Technical Approval of the insulation material are applicable. Follow the general regulations of the note 215 when the technical approvals are not available.
A tapered scheme, made by the manufacturer of the insulation boards, will be presented before the start of the works. The plan will be made up in function of:
- the dimensions of the roof;
- the place of the outlets;
- the minimum average thickness.
The following dimensions have to be used: