Chemical delignification is a form of timber decay that affects roof structures, particularly under terracotta tiled roofs. It occurs when salts (efflorescence) migrate from the tiles into the timber battens and rafters, breaking down the lignin – the natural “glue” that holds wood fibres together. Over time, the timber surface becomes soft and “hairy”, weakens structurally, and can eventually collapse if left untreated.
In Perth and other coastal or high-salt environments, chemical delignification is sometimes found in older terracotta roof systems. Understanding the cause, signs and treatment options is essential for homeowners, buyers and investors.
Before we explain in more depth what chemical delignification really is, we need to understand what products and conditions can lead up to this happening to the roof timber structure. So, let’s start from the beginning.
Continue reading “Chemical Delignification: Causes & Treatment”
