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From the Resene News – issue 2/2004 Radio waves - Historic radio transmitter building Built in the 1930s, this historic plaster concrete transmitter building has outlasted its bitumen barrier and various exterior coatings. Severely blistered, the exterior coatings became a cause for concern as this building is home to sensitive electronic equipment used for broadcasting the many AM radio programmes out over the airwaves.
Close inspection showed that the old coating system would require complete removal back to the bare substrate. Removal of this magnitude was a daunting undertaking exacerbated by the immense size of the structure and the softness of the bitumen. Collaboration between all parties teamed with previous experience and site trials culminated in the determination of the optimum removal method of ultra high pressure waterjetting. Care was taken to minimise damage to the underlying cementitious substrate by altering the blasting pressure to suit each section of the building. Each stage of the stripping was inspected to ensure complete removal of the bitumen residues had been achieved. Spooling areas were raked out and the reinforcing steel treated before being patch filled with epoxy mortar. The capping of the building was replaced for added substrate protection from weathering, then the bare plaster was sealed with Resene Sureseal pigmented sealer. Large structural cracks were cut out and filled with a flexible paintable sealant, while smaller cracks were treated with a brushed coat of Resene Thixalon 5. After all the cracks had been treated, two full coats of Resene Thixalon 5 followed by two finishing coats of Resene Lumbersider satin acrylic was used as the finishing system combining desirable colour options with a durable satin finish to help disguise the discontinuities in the old plaster finish. Colours were chosen with the assistance of the Resene RenderRite electronic rendering service to highlight the architectural features of the building and to assist with promotion of the client. From coated to bare and back to glam, this transmitter building will be keeping the airwaves humming. Client: Gary Fowles, Transmission Manager, Radio New Zealand |
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