Don & Low, the UK’s renowned vertically integrated manufacturer and creator of Roofshield, is uncovering a critical industry-wide issue affecting roofing membranes across the UK. Through ongoing testing, it has been established that leaks in membranes are frequently tied to the presence of timber treatments on certain battens commonly used in roofing applications. Notably, certain chemical components within timber treatments potentially impact all synthetic membranes. This testing, stemming from Don & Low’s technical expertise, reveals a significant concern affecting the entire roofing industry.

Several factors have contributed to the increased incidence of treated timber causing this effect. The change in the supply chain for roofing battens, affected by Covid disruptions and geopolitical events like the Ukraine-Russia war, has led to an emergence of non-traditional batten manufacturers, and these are coupled with different treatment processes and exceptional rainfall. During 2023, the UK timber market has been grappling with quality issues and incorrect grading to BS5534.

Don & Low is carrying out ongoing testing into issues of leaks, which has established a link between the presence of certain chemical components within timber treatments leaching from saturated battens affecting the performance of membranes. A common factor found throughout the majority of investigated installations was the presence of contamination on/in the membranes that compromised the water holdout performance.

Don & Low commissioned the BRE, the UK’s leading science-led construction research facility, to subject Roofshield to extreme weather testing. The testing, designed for primary roof coverings, subjected Roofshield to wind driven rain, installed with dry battens known not to contain chemicals that compromise water holdout. The results were conclusive – Roofshield exceeded the required standards for air-permeable roofing underlays, and no leaks were experienced.

Contractors should observe the installation guidelines and best practices. Battens should be dry to prevent chemicals leaching onto the membrane, and battens should not be treated in situ. We have observed the growing reports of skin issues by roofing contractors online and would advise the correct PPE to be worn.

Designed and manufactured in the UK, Roofshield remains industry tried, tested, and trusted for 25 years, certified by the BBA and backed by Don & Low – industry leaders in the manufacturing of construction membranes.

With a long history of technical competence and countless successes in its R&D and testing department, Don & Low continues its in-depth testing and research. The focus remains on providing industry professionals with valuable insights to enhance the performance and reliability of construction materials. This commitment to technical competence underscores Don & Low’s role as a responsible and innovative player in the field, contributing to the advancement and sustainability of construction practices.