The plastisol steel cladding roof was leaking as a result of corrosion where the cladding panels had been cut. Costings had been given to re-clad the entire roof however accessing the roof was prohibitively expensive.
THE SOLUTION – LIQUID ROOFING
We proposed the installation of a seamless, liquid spray applied, rapid cure, Polyurea liquid roofing system that could be installed entirely from booms without having to access the roof yet offer a similar life expectancy to that of a new plastisol steel cladding roof. Another consideration in this project was not disrupting the electrical switch gear below which controlled a large sewerage works.
Removing the corrosion with a high pressure jet
Initially the roof was prepared by method of high pressure spinning jet (3,000 PSI) to remove corrosion and unsound plastisol coating. This exposed the corroded steel below which was treated using Corroless EPF rust stabilising epoxy primer applied by brush and roller. Where perforations were found these were bridged using Corroless EPF reinforced with chopped glass fibre matt.
When applying Polyurea Roof coatings attention to detail is everything. Therefore at the perimeters of the roofs the void space between the capping detail and the roof itself was filled using a closed cell foam prior to coating application taking place.
Because we had specified Speciality Products Incorporated (SPI) Watershield III the Polyurea Liquid Roof coating could be applied directly to the aged plastisol cladding without the need for priming (other than the corroded areas) reducing both the cost and time scale of the project.
A comprehensive 10 year warranty was offered on this installation which has a life expectancy in excess of 25 years until first maintenance.