The following should be taken into consideration before project design:

• the humidity conditions of the rooms, i.e. steam pressure and steam vent
• natural ventilation, assuming a change of air in the quantity of 80 m³/h for the bathroom and WC cumulatively, 50 m³/h for a kitchen with an electric cooker and 70 m³/h for a kitchen with a coal-fired cooker or gas cooker, with a night reduction of the whole change value up to 20 m³/h per person
• an area of ventilating holes relating to a ventilation gap of 4-6 cm together with space over collar beams should be respectively:
  • 0.002 of a hipped roof end area and a minimum 200 cm³ per 1 running metre of the whole eaves for under-eaves openings
  • 0.001 of roof area and a minimum of 200 cm³ per 1 running metre of roof ridge or roof hip for roof ridge openings or top grates and along hips of an envelope roof

A ventilation gap between the membrane and insulation is not required with the use of high vapour permeable membranes. Stradommem high vapour permeable membranes should be laid with the printed side up. Membranes should not be laid on full roof boarding. The final roofing needs to be completed in the time determined by the UV stabilization parameter (see the table).

Product technical data sheet (PDF)

STRADOM S.A. reserves the right to alter the technical parameters.