rotpenetration

Rot penetration, or rotpenetration in some texts, is a term used in materials science and building pathology to describe the depth and extent to which rot-causing organisms invade a porous substrate, most often timber. It is used to assess the severity of decay, to diagnose damage, and to guide remediation decisions.

In wood, the concept encompasses various forms of rot, including brown rot, white rot, and soft rot. Brown rot degrades cellulose and hemicellulose, often leaving a brittle, cubically cratered wood, while white rot breaks down lignin and cellulose, producing a lighter and spongier texture. Soft rot tends to occur under high moisture and restricted oxygen, creating chambered, soft decay. Each type can penetrate from an exposed surface into the interior to different depths depending on conditions.

Penetration depth is influenced by moisture content and duration, temperature, wood species and density, grain structure, and the presence of cracks or voids that allow easier ingress. Assessment methods range from visual inspection and bore sampling to non-destructive techniques such as moisture measurement, imaging, or microscopy to estimate how far decay has advanced.

Prevention and remediation focus on moisture control and physical barriers, timely removal of decayed material, and the use of preservatives or coatings where appropriate. In severe cases, structural replacement or reinforcement may be required. While rot penetration is a practical concern in construction and conservation, terminology and measurement practices can vary by region and discipline.