Felt roofing is a common and practical choice in the UK, especially for flat roofs on homes, garages, and sheds. It’s popular because it’s both affordable and easy to install. With proper maintenance and consideration of weather conditions, felt roofing can last around 10 years, offering reliable protection from the elements. Though it may require occasional upkeep, this ensures your roof stays in good condition, preventing weather-related issues like cracking or warping.
Understanding how to care for your roof membrane is essential for keeping your home safe and extending the roof’s lifespan. In this article, we’ll explore the types of roofing felt, their benefits, and what factors influence the cost of refelting, giving you the knowledge to make smart decisions for your property.
Key Takeaways
- Roofing felt is essential for securing tiles and protecting against weather damage.
- The lifespan of roofing felt varies depending on the material, ranging from 15 to 50 years.
- Costs for refelting a roof can vary significantly based on size, condition, and material choice.
- Alternatives to traditional roofing felt include GRP and EPDM, offering different benefits.
- Professional installation is recommended to ensure durability and effectiveness, as the installation process is crucial for the longevity of the roofing felt.
- Roofing felt must be installed properly and maintained to achieve its maximum lifespan.
Introduction to Roofing Membranes
What is Roofing Felt?
Roofing felt, also known as underlay, is an essential layer when it comes to roofing supplies for a new roof. It is usually placed beneath tiles or slate and helps secure the roofing in place. Felt provides stability, and supports the locking systems between planks. It also reduces noise and allows the flooring to “float,” ensuring added sturdiness. Proper installation techniques are essential to ensure the roofing felt provides maximum stability and protection.
Primarily, roofing felt stabilises tiles, especially during winds or storms, and protects against rain, preventing leaks and water damage. This roofing material also helps insulate your home by retaining warmth during the colder months, reducing the need for constant heating and helping to lower energy costs. Alternatively, an EPDM membrane can be used, offering superior durability and longevity compared to traditional roofing felt.
Advantages of Using Roofing Felt
- Proven Reliability: Roofing felt is a well-established material, commonly used in both residential and commercial roofing projects.
- Effective Waterproofing: Its effectiveness in weatherproofing and waterproofing roofs has been demonstrated over many years.
- Cost-Effective: Felt is an affordable option that offers excellent value for money.
- Quick Installation: It can be installed relatively quickly.
- Long Lifespan: Roofing felt can last over 25 years.
- Strong Warranties: Manufacturers often offer warranties ranging from 20 to 30 years.
- Easy to Repair: Repairs are straightforward if needed.
- Fire Protection: Using a fire-rated top layer can provide a good level of fire resistance.
- Durable in Harsh Conditions: It can withstand ponding water and is resistant to UV rays, strong winds, and rain.
- Suitable for Commercial Properties: Roofing felt is ideal for commercial properties due to its cost-effectiveness and reliability, especially for flat roof designs.
Types of Roofing Felt
Asphalt Saturated Felt Asphalt-saturated felt is a common type of roofing felt. It is made by soaking a base material—usually organic or fibreglass—in asphalt. This type typically lasts about 15-20 years. While it is affordable and easy to install, it is not as durable as some newer options. It can tear easily, especially during installation or in bad weather, and may wear out more quickly when exposed to UV light or moisture. Compared to other roofing materials like TPO and PVC, asphalt-saturated felt has a shorter lifespan and less resistance to weather elements. Different types of roofing felt may require specific installation methods to ensure optimal performance and longevity.
Fibreglass Roofing Felt Fibreglass roofing felt is a stronger version of asphalt-saturated felt, using fibreglass as the base material. This type lasts longer, usually between 20-30 years, and offers better fire and tear resistance. Its improved durability makes it a great choice for projects needing a longer-lasting material.
Synthetic Roofing Felt Synthetic roofing felt is made from materials like polyethylene and offers a modern alternative to traditional options. With a lifespan of 25-40 years, it is very durable. Synthetic felt resists tearing, water, and UV rays well, making it ideal for roofs in harsh weather. Its lightweight nature also makes it easy to handle, making it a popular choice for long-term roofing solutions.
Rubberised Asphalt Roofing Felt Rubberised asphalt roofing felt combines rubber and asphalt for high performance. It can last anywhere from 30-50 years, thanks to its excellent waterproofing and self-sealing properties that help prevent leaks. This type is very durable and is especially useful in areas with extreme weather.
Bitumen Roofing Felt Bitumen roofing felt is similar to asphalt-saturated felt but has a coating of bitumen, which can be either oxidised or modified. It typically lasts between 20-35 years and is very resistant to water, UV rays, and temperature changes. The modified versions offer extra flexibility and longevity, making this type a strong option for durable roofing.
Estimating the Lifespan of Roof Felt
The lifespan of your roof felt largely depends on the type of tiles used, as they come in various styles and textures. Traditional roof felt under tiles can last around 30 years, depending on the conditions it is exposed to, as it is not as durable as granite. In contrast, modern roofing materials may not last as long due to a decrease in quality. The service life of roofing felt can vary, but it generally compares favorably to other materials like rubber and single ply roofs, which can achieve a service life of 25 to 50 years with proper installation and material choice. Although they tend to be more durable, they can also be more expensive than in the past. The lifespan of roofing felt can be significantly affected by the weather conditions it is exposed to, such as extreme heat, cold, or moisture.
When replacing roof underlay, opt for a more breathable option. Breathable roofing underlay works better with traditional materials and is a superior replacement for felt. Using the wrong type of felt increases the risk of condensation, which can damage your home and lead to higher costs. If the air in the roof space is warm and contains moisture, the roof can become cold during the winter months, causing water to condense on the underside of the roof.
Factors Affecting Lifespan
The lifespan of a roofing membrane is affected by several factors, including the quality of the material, installation, and maintenance. The right adhesive is essential to ensure a strong bond between the roofing membrane and the roof deck. Poor condition of the existing roof can compromise the performance of the new roofing membrane. Fixings needed to secure the roofing membrane can also impact its lifespan. An important factor in determining the lifespan of a roofing membrane is the type of material used. EPDM roofing membranes are known for their durability and can last for up to 50 years. Regular maintenance is essential to extend the lifespan of a roofing membrane. The cost of replacing a roofing membrane can be significant, so it’s crucial to choose a high-quality material that will last. Manufacturers’ guidelines should be followed during installation to ensure the roofing membrane is installed correctly. Approved contractors should be used to install the roofing membrane to ensure a professional and high-quality installation. Effective weatherproofing is essential to protect the roofing membrane from weather elements and extend its lifespan.
Flat Roofing Considerations
Flat roofing requires careful consideration of several factors, including the type of roofing membrane, insulation, and drainage. A flat roof replacement can be a complex project, requiring specialized knowledge and equipment. The choice of roofing membrane can significantly impact the performance and lifespan of the flat roof. Single ply roofing membranes are a popular choice for flat roofs due to their durability and ease of installation. The thickness of the roofing membrane can also impact its performance and lifespan. A car park roof, for example, requires a thicker roofing membrane to withstand the weight and traffic. The deck of the flat roof should be in good condition before installing a new roofing membrane. Cold temperatures can affect the performance of the roofing membrane, so it’s essential to choose a material that can withstand extreme temperatures. Life expectancy of a flat roof can range from 25 to 40 years, depending on the type of roofing membrane and maintenance. Regular inspections and maintenance can help extend the lifespan of a flat roof and prevent costly repairs. Considering the weather conditions in your area is crucial when selecting materials for a flat roof replacement.
How to Tell if Your Roofing Felt Needs Replacement
If your roofing felt becomes damaged or broken, it will require repair or replacement, as it will no longer provide adequate protection and may lead to a cold, musty environment. One of the most common reasons for replacing roofing felt is leakage. If your house experiences significant leaks after heavy rainfall, this is a clear indication that it needs to be replaced. Timely replacement is crucial to avoid complications in your roofing project. Maintaining the weatherproofing capabilities of your roofing felt is essential to prevent leaks and other weather-related issues.
Another sign to watch for is if your tiles are shifting or becoming dislodged more easily. This may indicate that the tiles are no longer securely fastened underneath the felt, and replacement is necessary to prevent potential hazards. Additionally, if there is leaking or condensation seeping through, it can negatively impact your health by clogging airways and causing other health issues.
Cost of Refelting a Roof
Source: myjobquote.co.uk
The cost of refelting a roof can vary quite a bit, depending on the size of the roof and its condition. Generally, felt roofing costs between £30 and £45 per square metre. For a medium-sized shed, you might spend around £250 to £450. Labour costs will also add to the total, usually around £200 per day. Costs can also vary based on standards and practices within the roofing industry. The installation process can also impact the overall cost, as proper installation ensures the longevity and effectiveness of the roofing felt.
Source: checkatrade.com
For those needing to replace a flat felt roof, the costs are different. Refelting an average-sized flat roof garage costs a ballpark of around £1,500.
If you need to replace the roofing felt under tiles, it’s important to assess how much of the existing felt requires replacement. For a small patch, the cost can be as low as £200, which covers about 4m². However, if the damage is extensive and the entire roof needs refelting, the cost will be significantly higher. On average, refelting an entire roof under tiles can cost around £4,800, though this can vary depending on the roof size, the type of tiles, and the other factors mentioned earlier.
Alternative Options to Roof Felt
While felt roofing is a reliable choice for flat roofs, there are several other alternatives available. Two popular options in the market are GRP (glass reinforced plastic) and EPDM (rubber roofing). On the other hand, EPDM rubber roofing boasts an impressive lifespan of approximately 50 years. It effectively repels moisture and offers an attractive appearance. However, its installation can be complex. GRP has gained significant traction in the UK, but it generally has a lifespan of around 20-25 years and can be up to £30 per metre more expensive than traditional roofing felt. When considering alternatives, it’s important to evaluate their weather resistance to ensure they can withstand various environmental conditions.
Another excellent option is a single ply roof, known for its durability and ease of installation. Single ply roofs can last between 25 to 40 years, depending on factors such as design, material selection, and proper installation. Proper installation and a thorough survey of the existing roof condition are critical to avoid future failures.
For those considering a DIY approach, self-adhesive grey roof felt is a more affordable and simpler alternative to install.
Maintenance and Inspection
Regular maintenance and inspection are crucial to extend the lifespan of a roofing membrane. A roofing contractor should be hired to inspect the roof regularly and perform any necessary repairs. The cost of maintenance and repairs can be significant, but it’s essential to prevent more extensive damage. Leaks can be a significant problem in flat roofs, so it’s essential to inspect the roof regularly to detect any signs of damage. The advantages of regular maintenance include extended lifespan, reduced repair costs, and improved performance. Manufacturers recommend regular maintenance to ensure the roofing membrane functions as intended. Asphalt coating can be used to protect the roofing membrane from UV rays and extend its lifespan. Insulation is also essential to reduce heat loss and prevent condensation. Building owners should prioritize regular maintenance to ensure the roofing membrane lasts for its expected lifespan. By following manufacturer guidelines and performing regular maintenance, building owners can extend the lifespan of their roofing membrane and prevent costly repairs. Proper installation techniques are crucial to ensure the roofing membrane remains effective and easy to maintain.
Conclusion
Roofing felt is a reliable and cost-effective option for protecting your home’s roof, with different types offering various levels of durability and weather resistance. Whether you are refelting a roof or exploring alternative materials like GRP or EPDM, understanding the options available will help you make the best choice for your property. Regular inspections and timely replacements of roofing felt can prevent significant damage and extend the lifespan of your roof.
Maintaining the weatherproofing capabilities of your roofing felt is essential to ensure the longevity and effectiveness of your roof.
Frequently Asked Questions
How long does roofing felt typically last?
The lifespan of roofing felt depends on the type. Asphalt-saturated felt lasts around 15-20 years, fibreglass felt about 20-30 years, synthetic felt between 25-40 years, rubberised asphalt felt 30-50 years, and bitumen felt 20-35 years. On a low slope roof, these materials can offer similar longevity, with some like rubberised asphalt felt lasting up to 50 years.
The lifespan of roofing felt can also be influenced by the weather conditions it is exposed to, such as extreme heat, cold, or moisture.
What are the signs that my roofing felt needs replacing?
Signs include leaks after heavy rain, dislodged or moving tiles, and visible damage or wear. If your roof underlay is causing condensation or dampness, it might be time for a replacement. Replacing old roofing felt can also improve the curb appeal of your home.
How much does it cost to refelt a roof?
The cost of refelting a roof varies depending on factors like the size and condition of the roof, the type of felt used, and accessibility. On average, costs range from £30-£45 per square metre, with full roof refelting potentially costing around £4,800.
Are there alternatives to traditional roofing felt?
Yes, alternatives include GRP (glass reinforced plastic) and EPDM (rubber roofing). These materials offer different benefits, such as longer lifespans and greater durability, though they may come with higher upfront costs.
Can I refelt my roof myself?
While it’s possible to refelt a roof as a DIY project, it is recommended to hire professionals. They have the expertise, tools, and materials needed to ensure the job is done correctly, preventing future issues with wind and water damage.
How can I determine the number of felt layers my roof requires?
The ideal number of felt layers depends on factors such as climate, roof slope, building usage, and manufacturer guidelines. It’s advisable to consult with roofing professionals before starting a project to receive tailored advice on the best layering strategy for your roof.
Are there UK regulations on the number of felt layers?
In the UK, building regulations don’t universally dictate the number of felt layers required. However, in Scotland and Northern Ireland, at least three layers are typically required for new commercial buildings. Local planning authorities may also have specific material requirements based on building codes or permits, so it’s essential to check the rules relevant to your area and project.
