The clients internal valley gutters had been allowing water ingress in to the factory production area below for many years, with previous attempts to resolve the issue proving unsuccessful. Due to the age of the structure the hot dip galvanizing protecting had started to breakdown, with surface corrosion clearly visible.
Furthermore due to the presence of asbestos in the form of asbestos cement roofing sheets, potentially contaminated water could be entering the building below.
Firstly all organic growth was contained and removed. Due to the possible presence of asbestos fibres the moss and debris was treated as hazardous, being double bagged and disposed of by licensed asbestos disposal contractors. The drain outlets were then blocked and connected to 1 micron filters to contain any asbestos fibres that may have been released prior to preparation by method of high pressure spinning jet to remove all surface corrosion and contaminants present. The asbestos cement gutter sides were prepared using a biocide and detergent to keep disruption to a minimum.
Once satisfied with the preparation works the gutter was primed throughout with Corroless EPF, a unique rust stabilising epoxy primer with exceptional adhesion properties. 0.4 – 0.8mm quartz aggregate was broadcast into the uncured epoxy primer to promote adhesion of the subsequent Polyurea membrane. Furthermore by providing a heavily profiled substrate the concern of exceeding the overcoat interval due to the temperamental UK climate was removed.
All nuts, bolts and joints were then isolated form the membrane application by the use of a high modulus polyurethane jointing compound. Finally the gutter was lined throughout using a spray applied, rapid cure pure polyurea membrane,, forming a seamless elastomeric lining. Polyurea coatings remain fully flexible when cured, allowing them to accommodate the expansion and contraction within the gutter. The Polyurea coating applied here (Advanced Polymerics Cemspray 113) can in fact elongate 380%.
Our lining installation resolved the water ingress issue for the client and they have since lined a further problematic gutter.