A mezzanine floor system which is protected using a double layer of 2 x 15mm thick PROMATECT®-250 will provide 90 or 120 minutes loadbearing capacity, fire integrity and fire insulation. The 2 x 15mm thick boards will also provide fire protection to the hot rolled steel beams supporting the cold rolled joists, depending on the section factor (A/V) value of the steel section. It is important that the section factor value is calculated for the steel beams to check that the 2 x 15mm thick boards will provide the correct level of protection. Contact our Technical Services Team who will provide guidance on how to carry this out. 2 layers of 15mm PROMATECT®-250 caters for section factors of up to 140m-1 for 120 minutes, or section factors of up to 350m-1 for 90 minutes.

Please see our TDS 039 for more information.