Roof felt is one of the key layers protecting your home from the elements. Whether it’s for a shed, garage, flat roof or beneath the tiles of your pitched roof, replacing old or damaged felt can prevent leaks, damp and costly repairs down the line.

In this guide, we’ll break down the average costs of refelting a roof in the UK, look at what affects those costs, and explain how the process works.

How much does it cost to refelt a roof?

The cost of refelting a roof depends on the size, type of roof and accessibility. Below are typical price ranges (excluding VAT):

These costs are estimates based on our database of tradespeople. They may not include additional materials required to complete the job properly, such as joists or insulation boards.

Factors affecting the cost of refelting your roof

Refelting your roof can be a big job, and often the more work that needs to be done, the more factors there are that can affect the overall cost. Here are some of the most common things that can affect the cost of refelting your roof:

• Roof size: As you’d expect, larger roofs require more materials and take longer to complete than smaller roofs so usually cost more to refelt. However, you may find that materials cost less per square metre for very large roofs.
• Roof type: Pitched roofs cost more to refelt than flat roofs because it involves taking tiles off the roof and you’ll also need scaffolding.
• Condition of existing roof: If your roof joists or insulation boards need replacing along with the felt, expect to pay more.
• Type of felt used: Felt for shed roofs is much cheaper than torch-on felt or self-adhesive felt.
• Location: Labour costs vary across the UK. Prices are typically higher in London and the south east as the cost of living is higher there.

At HaMuch, we use our database of hourly and daily rates for roofers across the UK to estimate the cost of different roofing projects in your local area. Take a look at our roof refelting cost table and find your nearest town or city to get a more accurate estimate for your home.

What does roof felt do and where is it used?

Roof felt acts as a secondary waterproof barrier beneath your tiles or slates on a pitched roof, and is the main waterproof later on a flat roof. It prevents rainwater and moisture from penetrating into your roof structure, especially if tiles become damaged or water is blown under the edges.

Roof felt is commonly used in:

• Pitched roofs: Under the tiles or slates as a waterproof membrane
• Flat roofs: As the main weatherproofing layer, often applied using heat
• Shed and outbuilding roofs: A cost-effective way to protect smaller structures
• Garage roofs: Especially with timber-framed garages or flat roof designs

Roofing felt is a vital part of many roofs and if it gets damaged, water could leak into your loft or through your ceilings and cause further problems such as rot or staining.

How often should roof felt be replaced?

Roof felt can last anywhere from 10 to 50 years, depending on the type and quality of the material used:

• Shed felt: Shed felt is typically the cheapest type of roof felt, and will last around 5 years up to around 10 years if well-maintained
• Torch-on felt: A properly installed torch-on felt should last at least 10 years, and with proper maintenance it could last as long as 30 years
• Roof felt under tiles: Non-breatheable felt can last between 20-30 years, while breathable felts could last as long as 50 years

If you think your roof felt is coming to the end of its life, conduct regular inspections of your roof. Signs your roof felt may need replacing include water leaks, noticing sagging felt in the loft, or visible tears you have a flat roof.

Can you replace roof felt without removing tiles?

It is generally not possible to replace roof felt under a tiled or slate roof without removing at least some of the tiles. Be wary of any roofer who says that they can complete the work this way, as it probably means they are not replacing the felt entirely.

To properly replace the felt, a roofer needs to:

1. Remove tiles or slates from a section of the roof.
2. Take out the old felt and battens if needed.
3. Install felt.
4. Reinstall the battens and tiles.

This makes it a labour-intensive job, especially on larger roofs, which is why replacing under-tile felt is more expensive than felt-only flat roof work.

You may be able to have patch repairs done to your felt without removing tiles if you notice small leaks in your pitched roof, but in the long term you will need to have the felt fully replaced.

How long does it take to refelt a roof?

The time it takes will depend on the roof type and scale of the job:

Weather also plays a role in how long it will take to refelt the roof. The conditions need to be dry and mild, particularly on flat roofs that require torch-on installation.

Can you refelt a roof yourself?

For small jobs such as shed roof refelting, you can do this yourself if you’re a competent DIYer. You’ll need mineral felt rolls, roofing nails or tacks and adhesive. Expect to spend £50-£100 on materials for a basic shed.

We’d never recommend refelting flat or pitched roofs, especially under tiles, yourself unless you have professional roofing experience. These jobs involve:

• Working at height
• Removing and reinstalling roofing components
• Ensuring watertight installation in line with building regulations

If you don’t install the roof felt properly, you could end up with leaks, insulation damage and other costly repairs down the line, which could make it cheaper to hire a professional to do the job in the first place!

Ready to get started? Post your job on HaMuch now and connect with local roofers who can offer a tailored quote for your refelting project – whether it’s for a small outbuilding or your entire roof.

Estimates for common roofer jobs;

Rates for other trades