We were contacted by the client to provide a proposal and detailed schedule of works to carry out dilapidation repairs to a historic building, when River Island moved to new premises. The site is in Leeds City centre so, as you can imagine, this offered a unique and challenging set of circumstances including façade cleaning up to a height of 25 metres whilst the general public passed in the street below, as well as a tight 2 week deadline.
We were approached because of our expertise in the field of soda blasting, indeed it was this technique which was to form the hub of the cleaning and restoration project. There were considerable areas of sandstone, marble and brickwork that needed to be cleaned, including the removal of graffiti.
Soda blasting uses compressed air to fire small crystals of sodium bicarbonate (blasting soda) at the surface to be cleaned. It has a low environmental impact and is very gentle on masonry and other materials used in construction including soft metals like copper and zinc. It has a hardness of about the same as talcum powder so will not abrade or scratch harder surfaces. Unlike conventional blast cleaning systems, it doesn’t work by abrasion. The crystals of the blasting soda ‘explode’ on contact with the surface and it is the energy released that disrupts the bonding within the soiling and between the soiling and substrate. The compressed air that is used to fire the blasting soda at the surface to be cleaned then simply blows the contamination from the building.
We needed to take three distinct approaches to the soda blasting. Firstly, the sandstone was dry blasted using a vortex spinning blast head nozzle with a pressure set at 2 bars. The operators varied the pressure as required to remove the stone staining and obtain a perfect finish.
Secondly, we used our mobile soda blasting equipment with a fan nozzle set at 1.5 bars pressure to restore the brickwork.
The third soda blasting task was to clean up the marble. We needed to remove ingrained dirt as well as graffiti without damaging the surface. Conventional blast cleaning or chemical cleaning could have damaged the stonework so we chose to use a soda blaster with a vortex spinning blast head wet nozzle and pure soda blast blend.
In addition, we were required to carry out limescale removal, cladding cleaning, bird fouling removal and stone repairs. We used a variety of our own formulated cleaning chemicals to achieve the desired results. The cladding was cleaned and protected with our superb single-visit Easy Metal Clean and Polish whilst the bird fouling and associated odour was dealt with using Dekon 50 and Citrus RTU.
Another successful commercial cleaning project was duly completed on time and budget by the UK’s most respected soda blasting company!