The Midland Hotel is a Grade II, Listed art-deco building, built in the 1930s. Refurbishment took place in 2008. Finished in ground glass render and part finished in a silicone render, believed to be K-rend.
Showing various biofilm growths around the building – Trentepohlia (red algae), Chemoorganotrophic fungi (dark marks), combined with general atmospheric staining, road dirt, diesel fumes etc.
Building has previously been cleaned using high pressure water. This, may have, when combined with certain detergents removed atmospheric “dirt”. This process alone will not address the root of the problem, which is actually microorganisms colonizing the surface.
There is also a secondary problem, that as these microorganisms grow, they also excrete bi products, which etch and stain the surface. Whilst these are not actually living organisms, they do stain, so this also needs to be removed.
We undertook to chemically clean and treat for growth, to achieve the desired results. Whilst we cannot guarantee that all staining will be removed, the process is fairly predictable and we were certain that the process used, will vastly improve the aesthetics of the building.
We then treated the whole of the build with a bio-degradable biocide that sits within the fabric of the render . Overtime this leeches out continuing to clean the render.
More information regarding the Midland hotel can be found here