Felt, EPDM or GRP: Which Flat Roof Is Best for Your Home?

If you’re looking for the perfect flat roof for your property, you’ll most likely have been offered three main options: felt, EPDM rubber or GRP fibreglass.

And, in this article, we’re here to help you determine which option offers the best match for your home.

There’s no one answer to which is the best type of flat roof. The right choice for your property will depend on a number of key factors, including the size and shape of your roof, your intended use case, and your budget.

Below, we’ve outlined the main differences between these three roof types, to help you make an informed and confident decision.

What is a felt flat roof?

A felt flat roof consists of layers of bitumen roofing felt, plus a mineral surface (to give the roof weather resistance). The roof is installed in layers, with the felt material being heat-bonded to the roof’s surface.

These roofs are a great durable, dependable and cost-effective option. They are widely used in garages, sheds and outbuildings.

Plus, modern torch-on felt systems are far more efficient than older models. They achieve a high performance durable, waterproof and weatherproof finish.

If installed by a professional, a felt roof typically lasts around 10-20 years (depending on the choice of system, maintenance and the degree of weather exposure). It’s important to note that these roofs can be vulnerable to damage and deterioration over the years, especially if water is left to collect on the surface.

Felt flat roofs are a good match for property owners that:

• Are adding a roof to a garage or outbuilding
• Want a straightforward and cost-effective solution
• Want a dependable, tried-and-tested system

What is EPDM rubber roofing?

EPDM is a synthetic rubber membrane, which typically comes in the form of large sheets. These are designed to cover simple roof shapes with minimal joints required. Instead, the membrane is either bonded or mechanically fixed to the prepared roof deck. Particular attention is paid to the roof’s edges, and any drainage outlets or upstands, to ensure full water resistance.

EPDM rubber roofing is a popular choice for garages and property extensions. It is highly weather resistant (including long-term water, UV and temperature resistance), flexible, and lightweight. What’s more, these systems offer a predicted lifespan of around 20-40 years (depending on the product, and the installation quality).

EPDM rubber roofs are a good match for property owners that:

• Have a straightforward roof shape, which is relatively flat
• Want to prioritise durability and low maintenance requirements
• Are looking for a long-lasting solution

What is GRP fibreglass roofing?

GRP stands for glass-reinforced polyester. But, it is also commonly known as fibreglass. This material is formed using a combination of resin and reinforcing matting, which is then cured. The result is a hard, seamless and waterproof material.

GRP roofing is ideal when a rigid finish is preferred. For example, if the roof may need to accommodate foot traffic. It can also be well suited to more complex roof shapes (so long as a professional team are enlisted to work on the details).

These roofs have a typical lifespan of around 20-30 years+ (again, depending on the system chosen and the conditions that it’s exposed to).

GRP fibreglass roofs are a good match for property owners that:

• Want a hard-wearing roof
• Need a roof that can be walked on
• Have a roof with awkward shapes or detailed edges

Which flat roof should you choose?

Ultimately, there’s no single “best” material for you to select. The right choice for your property depends on a combination of factors, including how the roof is used, its size and shape, and your budget.

Generally speaking:

• EPDM rubber is a great match for simple extension and garage roofs
• GRP fibreglass suits walk-on areas and roofs with awkward shapes
• Modern torch-on felt is a dependable, cost-effective option for garages and outbuildings.

Critically, it’s the quality of installation that matters the most – Even more than the choice of material.

The quality of the deck underneath, ensuring the correct drainage falls are present, and achieving well-finished edges and upstands are all the criteria that decide whether a flat roof lasts 15 years or 40.

So, you should prioritise working with an experienced local roofer, who can assess your roof and recommend the right system for your context.

At Stapleford Roofing, we install felt, EPDM and GRP flat roofing systems. We are highly trained and fully accredited, and are proud to be the trusted roofing installer of property owners across Nottingham & Derbyshire.

To find out more about our services, or to get tailored guidance for your property, our team are on hand to help.