Have you ever come across red ash in concrete before? Red ash, also known as clinker, was used as a building material in the UK primarily between the late 19th century and the mid-20th century, roughly from the 1880s to the 1950s. It was particularly prevalent during the Post-War reconstruction period when there was a significant demand for building materials, and traditional supplies were limited. The use of red ash in concrete was driven by its availability as a byproduct of industrial processes, such as coal burning. However, over time, the detrimental effects of red ash on concrete structures, including the potential for 'bubbling' floors and cracks, became evident, leading to a decline in its use. This is because red ash contains sulphate which exposed to moisture causes the concrete to expand. You can still see evidence of this in many properties today from the Post-War period. For minor issues, surface treatments such as epoxy coatings or sealants can help mitigate the effects. In most cases, you may be need to remove and replace the affected concrete to ensure structural integrity. In one property I was selling, a thorough inspection revealed a complete drainage collapse beneath the kitchen floor, which was only discovered because of the sulphate damage.

Posted by Chris at 2024-06-10 12:05:56 UTC