Standing seam single lock roof installed at Blairgowrie project Architectural Cladding Australia A standing seam single lock roof system from Architectural Cladding Australia is being installed at the Mirino St project designed by Seaspray Homes in Blairgowrie. The under-construction building will feature the standing seam single lock system in PVDF Zink Grey Aluminium on the roof. The roofing is being installed by Retro Roofing for Seaspray Homes.