How Long Does Roof Felt Last?

Insulation, Membranes & Felts
Screwing on roofing felt

Composed of a base made of natural or synthetic materials and coated with a protective asphalt layer, roofing felt is a superb line of defence against water ingress whilst still allowing proper ventilation to prevent mould growth. It's an optimal candidate for flat roofs as well as certain pitched roofs and boasts a life span that can reach up to 30 years.

Providing a defensive layer between the roof deck and covering, you’ll find it to be an essential piece of your roof, and one that needs to be maintained well if you want to get as much effective use out of it as possible.

When it comes to felting your roof, you have 3 options to choose from: shed felt, self-adhesive felt and torch-on felt.

Felt Type




Shed felt is a roofing alternative that is only suited for sheds and other smaller garden buildings. Typically, available in multiple colours they suit well-manicured gardens very well.

When installing this felt, to get the most out of it, you should always keep in mind that the bitumen in your shed felt will swell in warm weather and compress in cold weather.



Self-adhesive roof felt is an excellent choice for a beginner DIY project as it allows the roof covering to be installed without the use of exposed flames. Cost-effective, yet durable and long-lasting it is perfect when the time comes to freshen up your garage roof. When installed, the felt will self-bond to the substrate after the release film is pulled off the bottom. This makes it an excellent choice for minor refurbishments and repairs.



Torch-on felt involves melting three layers of bituminous felt onto the roof using a blow torch, resulting in a high-quality, weatherproof finish. These layers are usually composed of a vapour control sheet, a strengthened felt, and a cap sheet with a mineral finish. Building codes necessitate the use of all 3 layers when utilising the torch-on technique in a habitable area of a house. However, just 2 may be necessary for sheds and garages.

Due to the use of an exposed flame, we recommend that this method of Roof Felting only be carried out by professionals.

How Long Should Roof Felt Last

When trying to determine the lifespan of your felt, there are numerous factors to consider. Though there are some key factors to keep an eye out for, we’ll address these below. All in all, however, how long your covering lasts will depend on how well it has been maintained. While it is true that this form of roofing requires little care, inclement weather can prove problematic and so you should always check your felt after heavy rain, wind or snow.

On average, each type of roof felt will last a minimum of 10 years as a standard, though of course with the right care and maintenance they can surpass that. Torch-on roof felting is the most durable of all felts, with a life expectancy of around 15-30 years. Next is self-adhesive roof felt which sits comfortably at 15-20 years and lastly is Shed Roof Felt with a life expectancy of 10-15 years.

When to Replace or Repair My Roof Felt

As previously mentioned, well-kept roof felt can achieve a lifespan of up to 30 years- but how do you know when the time comes to replace or repair it?

  • Air Bubbles: When noticed early, this is simple to repair but, if left to develop, the bubbles can grow to the point where they pop and cause irreparable damage.
  • Fractures/Cracks: This will probably be the first thing that you notice, and when this happens it is usually a good sign that you need to replace your roof felt. While minor breaches can be easily repaired, a rupture over the entire felting necessitates replacement.
  • Moss/Mildew Growth: Fungus and mildew might not appear to be a cause for concern, but it does indicate water accumulation on your roof. If neglected, water damage can cause considerable complications which will necessitate a total roof replacement.
  • Water Pooling: When water is left on felt, it adds stress to the roof and can lead to cracking and water penetration. Hiring an expert is the right approach to attempting to salvage the roof; but, if the problem has been accumulating over time, replacing the roof may be the only alternative.

For more information and advice on how to repair your felt, you can check out our comprehensive guide here.

How to Increase the Lifespan of My Roof Felt

If you already have roof felt installed or are looking to get some installed, check out the list below for some ways you can increase the lifespan of your roof felt:

  • Inspections: You should aim to get your roof felt inspected at least once a year. This will allow you to address any issues quickly, before they can cause serious (and costly damage).
  • Always Check Your Roof After Intense Weather: your roof will always be exposed to the elements. That is why it is important that after heavy storms or rain you check your roof for any signs of damage or general wear and tear. Water pooling may indicate drainage issues, which can lead to leaks.
  • Don’t Walk on Your Roof: If your roof is prone to surface damage, do not walk on it or use it as a platform for repairs.
  • Know When to Replace Your Roof: When it comes to your roof, cheaper short-term solutions are far more likely to lead to more costly repairs down the line. If you are ever unsure whether your roof needs to be repaired or replaced, always consult a professional.

Here at Roofing Megastore, we have a wide variety of roofing felts for all your DIY needs. Browse through our website today to see our options or get in touch with our award-winning team for more information.  Get in touch on 01295 565 565 or direct via our live chat below, we’ll be happy to help.

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