Bi Metallic Corrosion or dissimilar metal corrosion as it is sometimes known as, is defined as accelerated corrosion of a metal due to contact with a more noble metal or non-metallic conductor.
The less corrosion-resistant a metal, the more it experiences accelerated corrosion whereas the more corrosion-resistant a material is, it experiences reduced effects due to the cathodic protection effect.
Preventing bi metallic corrosion within buildings is essential, as the consequences of ignoring this can cause catastrophic failure of masonry support and see whole sections of masonry panelling fall off a building.
ACS mainly use 304 or 316 grade stainless steel, it needs to be isolated away from steel used in SFS (steel frame support). Isolation pads are available to stop bi metallic corrosion but also to prevent acoustic and thermal transfer.
Other ways of isolating the two materials could be to use bitumen paint or a red oxide coating
Article originally published on 23rd October 2018