CONDENSATION CONTROL
Spray-applied polyurethane foams (PU foam) meet the Building Regulations in respect of condensation control by compliance with the Approved Document F 'Alternative Approach' for non-ventilated roofs. Calculations are made using the method in BSEN ISO 13788:2002 (and BS 5250 Appendix D): Code of Practice for Control of Condensation in Buildings. Surface and interstitial condensation on all building surfaces can easily be prevented. Many members provide these condensation risk calculations free of charge.
The ultimate pitched roof design is 100mm PU foam or fibre at ceiling joist level, unventilated loft space and 85mm of foam at rafter level to provide the perfect balance between optimum thermal performance and zero condensation risk.
This construction retains the storage usage of the loft space, negates the requirement for insulation to pipes and tanks and installed roof ventilation systems and achieves a U-value of better than 0.16W/m2K.