What is a roofing membrane, and how do you choose the right one?

Roofing membranes play an essential role in protecting buildings from the elements, so choosing the right one for your requirements is vital, or you may face costly problems later on. But how do you know what the right option is for you?

Before deciding what roofing membrane is suitable for you, it’s essential to understand roofing membranes and how they work. But how do you choose the right membrane for your specific needs? It comes down to asking the right questions.

This article will cover what a roof membrane is, the types, the factors to consider when choosing, and what questions to ask.

choosing a roofing membrane

What is a roofing membrane?

A roofing membrane is a type of roofing material designed to provide a waterproof layer and protection to a roof to eliminate the risk of expensive damage caused by leaks, damp and mould

They’re typically used in low-slope and flat roofing systems where traditional roofing materials like tiles may not effectively prevent water penetration.

What does a roof membrane do?

Roof membranes prevent external moisture from reaching the underlying structure while allowing internal moisture to escape and air to circulate, preventing dampness and mould from forming. They are a fundamental component for protecting a roof.

What are the types of membrane roofing?

Here are two main types of roofing membranes

Breathable. A breathable roofing membrane, also known as a permeable membrane, allows moisture vapour to pass through while preventing liquid from entering. Breathable membranes are typically used because they help reduce the need for separate ventilation.

Non-breathable. A non-breathable roofing or ‘impermeable’ membrane prevents moisture vapour from passing through. Non-breathable membranes should only be used on the cold side of insulation and should only be used where there is existing ventilation to allow condensation to escape (such as cold ventilated pitched roof systems).

Both membranes also resist challenging weather conditions such as heavy rain, hail and snow.

What roofing membranes to use on flat roofs?

Here are the top 3 membranes for flat roofing:

  1. EPDM (Ethylene Propylene Diene Monomer): A synthetic rubber material that resists UV rays, ozone gases, and harsh weather. Its flexibility makes it perfect for roofs with unusual shapes or those that expand and contract (due to temperature changes). This adaptability ensures a long-lasting, reliable seal, preventing leaks and damage over time.
  2. TPO (Thermoplastic Olefin): A single-ply roofing membrane made from a blend of polypropylene and ethylene-propylene rubber. TPO is known for its energy efficiency and heat-reflective properties. TPOs are tough against UV rays, punctures, and tears, making them ideal for roofs that need durability, like commercial buildings.
  3. PVC (Polyvinyl Chloride): A type of plastic roofing membrane that is flexible, durable, and resistant to chemicals, fire, and punctures. PVC membranes are often reinforced with polyester or fibreglass for additional strength. Their lightweight design and long-lasting durability make them applicable to various projects.

What is a single-ply roofing membrane?

Single-ply membranes, consisting of flexible synthetic polymer sheets crafted for flat or low-sloped roofs, represent a contemporary approach to waterproofing. Due to their ease of installation, durability, and waterproofing capabilities, single-ply membranes provide an effective solution tailored to flat roof applications, making them popular for commercial and residential roofing applications.

What factors should be considered when choosing a roofing membrane?

Deciding on the right roofing membrane isn’t a simple task. It requires thoughtful consideration to ensure you get a product that fits your needs. Here are 3 questions to keep in mind:

Question #1: What’s the best membrane for my roof type?

Whether the roof is flat or pitched will significantly influence the type of membrane that would be the most effective. For example, due to their waterproofing attributes, single-ply membranes are better suited for low-slope or flat roofs. Additionally, consider other requirements such as durability, UV resistance, and compatibility with the roof’s substrate. Ensure the membrane meets the roof’s specifications and matches any other specific needs or environmental factors.

Question #2: What is the manufacturer’s reputation and warranty coverage?

Choosing a membrane from a reputable manufacturer with a proven track record helps ensure product quality and reliability. Additionally, checking the warranty coverage provides assurance against defects and potential issues, offering peace of mind for your roofing membrane investment. For example, Alwitra single-ply membrane manufacturers have a 25-year guarantee and a 50-year service life, demonstrating the reliability of their products.

Question #3: Does the membrane need to meet fire safety standards and building codes?

Ensuring compliance with fire safety standards and local building codes is necessary for the building’s safety, health and well-being, and legal compliance. Checking for appropriate certifications and approvals ensures that the membrane meets regulatory requirements.

Final thoughts

When deciding on a roofing membrane, elements like the roof type, local weather conditions, and any relevant building codes must be considered. These factors should guide the choice of the most suitable membrane.

Equally important is the manufacturer’s reputation and the coverage provided by their warranty. Opting for a membrane from a trusted manufacturer with warranty support offers peace of mind, ensuring the roofing system is backed by industry standards.

Consider the long-term consequences of your decision. While the initial cost is a significant factor, prioritising the overall value and durability of the membrane can lead to significant savings over time. Investing in a high-quality membrane upfront may lower maintenance and repair expenses.