EXTERNAL FOAM & COATINGS
External foam and coatings allow large areas to be insulated quickly and easily and, by varying the depth, achieve any U-value specified. Sprayed foams bond permanently to any surface that is clean and free from grease and moisture. They form monolithic coatings which cover all contours and minor cracks. A range of elastomeric membranes is available to impart the required resistance to UV light.
Sprayed PU foams and Elastomeric weathercoatings, have now been used for refurbishment of existing roofs as well as new roofs for over 25 years. A range of systems is available, many having been tested and approved by the BBA. British Standards (BS7021 and BS5211) have also been written.
BUFCA members will be able to design a roof system to meet most requirements and supply a full specification, taking into account substrate preparation, primers, if required, suitable foam systems (typically 40-50 kg/m3 for roof applications) and type of weather coating. Systems are available for virtually all substrates including built-up felt roofs, asphalt, sheeted fibre cement, steel, aluminium, slate, concrete and even glass.
Once applied, the treatment is seamless and monolithic and will effectively weatherproof any roof. In addition, the treatment can be applied to any thickness to achieve a required U-value. Dew Point calculations can be made to determine thickness required for condensation control.