The base resin or finishing topcoat spills out onto the patio or splashes on a window.

GRP roofing splashes and spillages are a regular occurrence in the application process and can find its way onto a number of surfaces that you didn't aim for, including windows, doors, wood, plastics and concrete.

To permanently remove you need to deal with it while it's still curing. Acetone can be used for removing the resin system from most surfaces but you have to be careful using the product as it's extremely flammable.

Larger spillages on pathways or walls will require a hot pressure wash using a strong detergent to completely remove.

To avoid these problems make sure to mask off any potential areas like windows and frames that come into close contact with the roller and make sure to remove any planters or garden furniture at ground level and cover the floor with polythene sheeting.