GPB (Mastics) Limited are a specialist mastic joint sealing applicator operating in Southern England including Kent, Sussex, Surrey, Hampshire and London. We carry out mastic sealing and silicone sealing, apply intumescent fire sealants and carry out window and door mastic pointing, including expansion joint sealants. From individual private houses to large housing estates and blocks of flats we seal everything from external windows, doors and expansion joints to kitchens and bathrooms including any airtest sealing or fireproofing sealant works.