What causes a venting membrane to fail prematurely, and how to avoid it

Causes of Premature Membrane Failure

Venting membranes may fail prematurely due to a range of interrelated factors, starting with material degradation. Exposure to harsh environmental elements—such as intense ultraviolet (UV) radiation from sunlight, extreme temperature fluctuations, or prolonged contact with corrosive substances—can break down the membrane's structural integrity over time.

Material Degradation

UV rays can weaken the membrane's fibers, making it brittle and prone to tearing, while repeated cycles of freezing and thawing can create microcracks that compromise its waterproof and breathable properties.

Poor Installation

If the membrane is not laid evenly, or if seams and overlaps are not sealed properly, gaps can form that allow moisture to seep in or trap vapour inside.

Incompatible Materials

Using incompatible adhesives or fasteners can damage the membrane's surface, or fail to secure it firmly to underlying structures, leading to shifting or lifting.

Lack of Maintenance

Neglecting regular inspections means minor issues can escalate. Debris like leaves or bird droppings can block the membrane's pores, hindering breathability.

Specific installation errors that contribute to membrane failure:

Stretching the membrane too tightly during installation
Improper sealing of seams and overlaps
Using incorrect fasteners or adhesives
Failure to account for thermal expansion and contraction
Inadequate preparation of the substrate surface

Prevention Strategies

To avoid premature failure, a proactive approach is essential that addresses both installation and long-term maintenance.

Quality Material Selection

Select high-quality membranes designed to resist the specific environmental conditions of the installation area—such as UV-stabilized options for exposed roofs.

Professional Installation

Ensure installation is carried out by trained professionals who follow manufacturer guidelines, paying close attention to proper seam sealing, even laying, and compatible fastening materials.

Regular Maintenance

Implement a routine inspection schedule to remove debris, check for signs of damage, and address any small issues immediately before they worsen.

Key maintenance activities to extend membrane lifespan:

Bi-annual inspections, especially after extreme weather events
Clearing debris from membrane surfaces and drainage paths
Checking for and repairing small tears or punctures promptly
Ensuring adjacent building elements don't damage the membrane
Monitoring for signs of UV degradation in exposed areas

This proactive approach to material selection, installation, and maintenance preserves the membrane's functionality and extends its lifespan, ensuring long-term protection for the building structure.

Preventing Premature Failure of Venting Membranes