Single Ply or Felt: Which Flat Roofing System Is Best?

Flat roofs are a very popular style of roofing and is one of our most requested services. It has many significant benefits over installing traditional roofing styles. There are primarily two materials that we use for flat roofing – single ply and felt. Each has its own advantages over the other and this article will explore which flat roofing system is best out of the two.

Flat Roofing System - SPS Roofing Ltd
Flat Roofing System Project Completed For A Client by SPS Roofing Ltd

What is a single ply flat roofing system?

Single ply flat roofing is one of the most popular roofing materials and is widely used in domestic and commercial projects. It’s designed to be installed in one complete layer. As such, the system offers greater flexibility in terms of setting up and easily maintaining a flat roof. The finish of a single ply roof is usually black or white (there are other colours available) and it’s also resistant to UV radiation. This makes it one of the more superior materials in comparison to the alternatives.

There are mainly two types of single ply membranes: thermosets and thermoplastic. Thermosets are more commonly used for larger roof areas as they are ideal for minimising seams. These membranes are compounded from synthetic rubber polymers such as EPDM, CSPE and Neoprene.

On the other hand, PVC and TPO are more popular choices when it comes to thermoplastic membranes. They usually serve as a reinforcement layer that provides additional strength and stability.

Irrespective of the choice between the two membranes, both thermosets and thermoplastic membranes are easy to install, flexible and provide protection from UV radiation.

If you are still unsure of which type of single ply membrane to use, get in touch with one of our specialists at SPS Roofing who can recommend the best solutions based on your requirements.

What is a felt flat roofing system?

Felt flat roofs have been the go-to solution for many homeowners over several decades. Overtime, the process of installing them has changed from the traditional roll-on method to torch-applied felt roofing. A modern version of felt flat roofing is a 3-layer membrane system that’s far more superior in terms of waterproofing performance.

Felts can be easily sourced as it’s widely popular. If fixed properly, they can prove to be a very strong flat roofing system. However, one of the main drawbacks of felt flat roofing is that it can lead to splitting, UV damage and cracking over time if not properly maintained. This is why we always stress the importance of selecting a fully qualified contractor with the appropriate qualifications.

Flat Roofing System
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So, which is better? Single ply flat roofs or felt flat roofs

Having looked at pro’s and con’s relating to the two flat roofing systems, the choice between them depends on a few main factors as identified below:

  • Cost: Traditionally, felts have been cheaper to setup compared to single ply membranes. As such, it has been popular amongst homeowners who choose to install felt roofing on a budget. However, over the years, the cost of repairing and maintaining felt flat roofs can be significantly higher than single ply roofing. The latter is far more durable and therefore requires less maintenance despite the higher initial investment.
  • Lifespan: Typical roofing felt will last for 5-8 years whereas single ply roofing has an average lifespan of approximately 25 years and over. This is mainly due to the highly durable materials that are used in constructing the single ply membranes.
  • Environmental sustainability: At the end of its lifetime, felts become unusable and is therefore usually discarded. However, in addition to a longer lifespan of single ply membranes as mentioned above, they are more environmentally sustainable because they can be recycled unlike felts.
  • UV Ray Protection: Felts are more susceptible to UV rays and can contract and expand depending on its severity causing weak points on its surface. However, single ply membranes are more robust and have a stable waterproofing layer which makes it more resistant to UV rays.


Having discussed the pros and cons of each, we have concluded that despite the higher installation costs, a single ply roofing system seems to be a much more viable choice. However, it should also be noted that the recommendation could also vary based on your individual requirements.

If you are still not sure which flat roofing system would work best for you, get in touch or schedule a call with one of our roofing experts, and we will provide you quotation absolutely free.

Looking For A Qualified Roofing Company?

SPS Roofing Ltd is a highly rated roofing company based in Exeter operating across Devon and South West England including Somerset, Cornwall, Wiltshire, Gloucestershire and Dorset.