The existing bitumen waterproofing had failed and was allowing water ingress into the base of the silo, resulting in product loss. In addition the water ingress had corroded the lowest level of sheets requiring their replacement. The works taking place during the winter months presented an additional challenge.
We proposed the application of an innovative elastomeric waterproofing system that would provide a long term seal for the silo base.
Following the replacement of the corroded sheets by the client we prepared the concrete plinth by method of high pressure water jetting. The introduction of moisture was not a concern as the proposed specification can bond to a damp substrate.
Because the waterproofing material proposed can adhere to new galvanising without the need for abrasive blasting or a bonding bridge no additional preparation of the new sheets was required – other than a light wash to de-grease.
Once prepared a fillet of polyurethane sealant was installed at the interface between the metal sheets and the concrete plinth to isolate the subsequent membrane from this potential point of movement. Prior to its application the area was dried using roofing torches to ensure good adhesion.
Finally once satisfied with the preparatory works Corrolastic SG was applied in two coats by method of slurry brush. This flexible polymer modified cementitious coating can be applied to damp substrates and in temperatures as low as 5 degrees centigrade. The material contains recycled car tyres making use of an otherwise waste material. The polymer mixture interacts positively with the recycled rubber to form a homogeneous flexible waterproofing membrane that can even withstand 2.5 Bar of negative water pressure.
The client was very pleased with the works and another silo base sealing order was placed on the back of these works.