Most UK homeowners never think about their roof felt until it fails. It sits hidden beneath the tiles, doing a job that is easy to take for granted — until the loft fills with the sound of dripping water during a downpour, or a roofer peers through the hatch and announces that the underlay has given out.
Felt replacement on a pitched roof is one of the more involved jobs a domestic roofer carries out. Every tile has to come off, the old underlay stripped back to the rafters, new membrane installed and lapped correctly, and the tiles carefully reinstated. It is a full-day job at minimum on a small roof, and several days on a large one — which is why the quotes can seem significant when homeowners first see them.
This guide gives you the numbers you need to know what a fair quote looks like in 2026, explains the difference between the materials available and why it matters, and covers the signs that tell you the felt actually needs replacing rather than something simpler.
What is roof felt and why does it need replacing?
Roof felt — more accurately called roofing underlay or sarking felt — is the layer of material fixed directly to the rafters beneath the tiles or slates. Its job is to act as a secondary line of defence: if wind-driven rain or melting snow gets past the outer tile layer, the underlay catches it and channels it down into the gutters rather than into the roof void.
On most UK homes built before the late 1990s, this layer is traditional bitumen-based felt — a heavy, black, mineral-reinforced sheet that was the industry standard for decades. The problem with bituminous felt is that it ages. Exposed to years of heat cycles, UV light, and moisture, it becomes brittle, cracks along the rafter lines, and eventually shreds or collapses into the loft. Once it fails, you have essentially no secondary waterproofing on your roof at all.
Modern homes and recent reroofing jobs use breathable membranes instead — polypropylene or polyethylene-based underlays that are far more durable, manage moisture vapour more effectively, and carry design lifespans of 50 years or more. If your home still has the original felt from the 1960s, 70s, or 80s, there is a reasonable chance it is already compromised whether you have noticed it or not.
Signs your roof felt needs replacing
Because the felt sits beneath the tiles, you cannot see its condition from the street. The most reliable way to check is a loft inspection — either by you with a torch, or by a roofer who can give you a ground-level assessment before going further. Here are the signs that warrant attention:
Types of roofing underlay: which should you choose?
When replacing felt, you are not obliged to replace like for like. In fact, replacing old bituminous felt with a modern breathable membrane is standard practice — and usually the better long-term decision. Here is how the main options compare:
Traditional bitumen felt (BS 747)
The material that was on most UK roofs built before 2000
Bituminous felt comes in several grades — the most common for pitched roofs being Type 1F (a heavy-duty reinforced felt). It is waterproof and inexpensive to buy, but it is non-breathable, meaning moisture vapour that rises from the living space can condense on its underside and sit in the roof void. To manage this, loft ventilation was traditionally specified alongside it — a requirement that is often inadequate on older UK homes in practice.
Some contractors still install bitumen felt, particularly when matching an existing partial reroofing job or where cost is the primary driver. For a full re-felt on an older home, however, most reputable roofers now default to breathable membrane unless instructed otherwise.
- Cheapest underlay option
- Widely understood by all roofers
- Good short-term waterproofing
- Shorter lifespan — fails before tiles
- Non-breathable — condensation risk
- Requires separate ventilation provision
- Brittle when cold, prone to cracking
Breathable / high-performance membrane (LR or HR underlay)
What most roofers now install as standard on pitched roof jobs
Breathable roofing membranes are made from polypropylene or polyethylene fibre and use a microporous structure to block liquid water while allowing water vapour to pass outward. This eliminates the condensation problem associated with traditional felt and means they can often be installed without the separate tile batten ventilation slots that bituminous felt requires — simplifying the job and reducing long-term maintenance needs.
They come in two main categories: Low Resistance (LR) membranes, which are more breathable but require careful lapping details; and High Resistance (HR) membranes, which are less vapour-permeable but more widely compatible with all roof designs. For most domestic re-felting jobs, an HR breathable membrane is what you will receive unless your roofer specifies otherwise.
- 50-year design life matches or exceeds tiles
- No condensation issues
- Often no separate ventilation needed
- Lighter, easier to handle on site
- Now the industry default
- Higher material cost than bitumen felt
- More expensive brands vary in quality
- Must be correctly lapped — poor installation negates benefits
Reinforced / self-supporting membranes
For heritage, conservation, or exposed locations needing extra resilience
At the top end of the market, products such as Klober Permo Air, Actis, and reinforced versions of the major brands offer enhanced tear resistance, higher wind uplift ratings, and in some cases partial self-supporting spans between rafters. These are used on heritage properties, steep-pitch roofs, highly exposed coastal locations, or anywhere the standard breathable membrane may not be sufficient.
They add £0.80–£2.00/m² to the material cost over a standard breathable membrane and are rarely necessary for a standard domestic UK re-felt job. A good roofer will specify one only where the roof design or exposure genuinely warrants it.
Full cost breakdown by house size and roof type
The figures below are supply-and-fit guide prices for 2026, inclusive of scaffolding erection and strike, tile removal and reinstatement, old felt disposal, new breathable membrane, and any minor tile replacements identified during the job. They assume a standard UK tiled pitched roof. Slate roofs attract a 20–35% premium due to the additional care required when removing and reinstating slates.
| Property type | Approx. roof area | Standard tiles | Natural slate | Duration |
|---|---|---|---|---|
| Small terraced / 2-bed | 45–65 m² | £1,800–£3,000 | £2,400–£4,000 | 1–2 days |
| 3-bed semi-detached | 65–100 m² | £2,500–£5,000 | £3,200–£6,500 | 2–3 days |
| 3-bed end-terrace / link-detached | 80–110 m² | £3,000–£5,500 | £3,800–£7,000 | 2–4 days |
| 4-bed detached | 110–160 m² | £5,000–£8,500 | £6,500–£11,000 | 3–5 days |
| Large detached / complex roof | 160 m²+ | £7,500–£12,000+ | £10,000–£16,000+ | 5–8 days |
What drives the final price? The 8 factors roofers price around
Roof area and pitch
Larger roofs take longer and use more material. Steeper pitches (above 45°) slow the work down considerably and increase the scaffold complexity, pushing up both labour time and access costs.
Roof complexity
A simple dual-pitched roof on a terraced house is far faster than a roof with multiple hips, valleys, dormers, and chimney stacks. Each change of direction adds time — both for removing tiles carefully around junctions and for lapping the new membrane correctly.
Tile type
Modern concrete interlocking tiles lift off and go back quickly. Traditional plain clay tiles, handmade tiles, and natural slates require far more careful handling — each one is individual, fragile, and irreplaceable if cracked. This adds significantly to labour time and breakage allowance.
Batten condition
When the felt is stripped, the roofer will inspect the tile battens. If they are rotten, split, or undersized for the tile weight, they need replacing before the new felt goes on. On older homes, full batten replacement is common — add £300–£800 for a typical semi-detached.
Scaffolding requirements
Scaffold is usually essential for safe re-felting work. The hire cost ranges from £600–£2,000 depending on the height, size, and duration. Urban properties with limited access, terraced rows where a scaffold needs to span a pavement, or buildings adjacent to roads all attract higher scaffold costs.
Additional work uncovered
A re-felt job frequently exposes work that was not visible before: rotten fascias, failing ridge tiles, damaged flashing, or isolated areas of rafter damage. Good roofers flag these as separate quotable items rather than absorbing them silently or inflating the original quote.
Location
Labour rates vary significantly across the UK. London and the South East are the most expensive. Scotland, Northern Ireland, and parts of the North of England can be noticeably cheaper for the same scope of work.
Membrane specification
The difference in material cost between a basic breathable membrane and a premium reinforced product is typically £1–£3 per m² — modest in the context of the total job, but worth asking about to ensure your contractor is not cutting corners on the underlying spec.
What happens on site: the re-felting process
Understanding what a roofer actually does during a re-felt job helps you evaluate whether the quote reflects the real scope of work — and whether the team on your roof is doing it properly.
-
1Scaffold erection
A scaffold company (often subcontracted) erects a full perimeter scaffold to the required working height. On a two-storey property this typically involves two lifts. The scaffold will stay in place for the duration of the job plus any drying or additional work time.
-
2Tile removal
All tiles are carefully lifted, typically by hand from the top of each roof slope downward. Tiles are stacked on the scaffold boards by type and position to allow accurate reinstatement. Broken or damaged tiles are set aside. The roofer notes how many will need replacing at this stage.
-
3Batten and felt stripping
The tile battens and the old felt are stripped back to the bare rafters. The old felt is either bagged and removed from site or temporarily held on the scaffold for skip disposal. Rafter condition is assessed at this point — rot, splits, and undersized timber identified.
-
4Structural and batten repairs (if required)
Any rotten or damaged rafters are cut out and sistered with new timber. Fascia boards that are failing are replaced. New tile battens are fixed at the correct gauge for the tile type — the spacing must be precise to ensure correct lap and weathering.
-
5New underlay installation
The breathable membrane is rolled out from eaves to ridge, fixed to the rafters with clout nails or staples, and lapped at every joint to the manufacturer's specification — typically 150mm side laps and 100mm end laps. The membrane is tensioned correctly between rafters to allow any incidental moisture to drain down to the gutters rather than pool.
-
6Tile battens fixed over the membrane
New treated softwood tile battens are counter-batten fixed over the membrane at the correct gauge. Counter battens run vertically down the rafter to create an airspace between the membrane and the tile battens — important for breathability and drainage.
-
7Tile reinstatement
Original tiles are re-laid from eaves upward, with replacement tiles inserted where breakages occurred. Ridge tiles, hip tiles, and valley work are re-bedded in mortar or re-dry-fixed depending on the original method. Verge and eaves details are reinstated to match the original.
-
8Final inspection and scaffold strike
The roofer walks the completed roof to check every tile is correctly seated, ridges and hips are solid, and flashings (chimney, dormer, abutments) have been correctly re-dressed. Scaffold is then struck and removed from site, typically the following day or within the week.
What should be included in your quote — and what to watch for
- Scaffolding erection and strike
- Full tile removal and careful stacking
- Old felt and batten stripping and disposal
- Supply and installation of breathable membrane
- New tile battens at correct gauge
- Tile reinstatement including ridge and hips
- Replacement of any broken tiles identified during removal (number specified)
- Flashing re-dressing (chimney, abutments)
- Clear-up and waste removal
- Batten replacement if found to be rotten (quoted separately on discovery)
- Rafter repairs — structural timber work is usually a day-rate extra
- Fascia and soffit replacement
- Lead flashing replacement (re-dressing is usually included; new lead is not)
- Additional tile purchases beyond the estimate
- Gutter clearing or replacement (often done same visit but quoted separately)
- VAT — always confirm whether the quoted price is ex-VAT or inclusive
"Can you confirm in writing exactly what is and isn't included — specifically whether battens, structural timber, and lead flashings are in scope — and whether this price is inclusive of VAT and waste disposal?"
Re-felt only vs full re-roof: which makes more sense?
When the felt fails on an older roof, homeowners often ask whether they should go the whole way and replace the tiles at the same time — particularly if the tiles are themselves ageing, weathered, or a combination of mismatched replacements from previous patch repairs.
| Scenario | Best approach | Why |
|---|---|---|
| Tiles structurally sound, 10–20 years remaining life | Re-felt only | No reason to replace serviceable tiles. A breathable membrane will outlast them. |
| Tiles 30–40 years old, significant loss of surface grain | Consider full re-roof | Tiles will need replacing within 10 years anyway. Labour and scaffold costs are the same — materials are the only extra. |
| Tiles fragile, many already cracked or broken | Full re-roof | Removing and reinstating fragile tiles increases breakage — you may end up replacing most of them anyway at higher cost. |
| Natural slate, age unknown but some slates slipping | Specialist assessment first | Good Welsh or Cornish slate can last 100+ years. A specialist can tell you whether the slates themselves are worth keeping or have reached nail-sickness. |
| Re-felt + known ridge / hip failure | Combine the work | Ridge and hip work requires the same scaffold and access. Do it in one visit and save the scaffold hire cost on a separate job. |
How to get a fair quote and compare roofers properly
- ✅Get three written quotes — not verbal estimates. Each quote should break down materials, labour, scaffold, and any likely extras separately. This is the only way to make a meaningful comparison between contractors.
- ✅Confirm the membrane specification — ask which breathable membrane brand and grade they are pricing. "Breathable felt" covers products ranging from budget imports at £0.60/m² to premium 50-year-warranty membranes at £2.50/m². The difference over a full roof is £80–£400 in materials.
- ✅Ask how many tiles they expect to replace — a good roofer will give you an estimated number of tile replacements upfront rather than presenting a bill for surprises at the end. If they say "we'll let you know when we open it up," that is a reasonable answer — but they should give you a contingency figure in writing.
- ✅Check their insurance — public liability cover of at least £1m is essential for re-felt work. Request a copy of the certificate before any work starts, not on the day.
- ✅Confirm scaffold is included — some roofers quote without scaffold and add it as a separate line once you have agreed the job. Ensure scaffold erection and strike is explicitly included in the written price.
- ✅Check whether the quote is VAT-inclusive — a VAT-registered roofer must add 20% VAT. On a £4,000 job, that is £800. Always confirm whether the quoted figure is net or gross before signing anything.
- ✅Agree a payment schedule — a deposit of 20–30% on confirmation is normal. Stage payment on scaffold erection or material delivery is reasonable. Never pay the full amount before the job is complete to your satisfaction.
Are you a roofer getting enquiries for re-felt and re-roof work?
Homeowners searching for pitched roof felt replacement in your area are ready to hire — they just need to find a contractor they can trust. We help UK roofers appear at the top of local Google results and generate direct enquiries without Checkatrade or MyBuilder. Get a free visibility audit to see where you stand today.
✅ Thank you. We'll be in touch within 1 business day.
Frequently Asked Questions
How much does it cost to replace the felt on a pitched roof in the UK?
For a standard 3-bedroom semi-detached house, pitched roof felt replacement in the UK costs between £2,500 and £5,000 fully installed in 2026, depending on the type of felt or membrane used, roof size and complexity, tile type, and scaffolding requirements. Larger detached properties can run from £5,000 to £9,000 or more. All prices are supply-and-fit, inclusive of tile removal, new underlay, and tile reinstatement.
How do I know if my roof felt needs replacing?
The most common signs are water dripping into the loft during or after rain even though tiles appear intact; torn, crumbling, or visibly sagging felt visible from inside the loft; dark staining or mould growth on loft timbers; and daylight visible through gaps in the underlay. Felt that has failed but has not yet caused internal water damage can often be identified by a roofer inspecting the loft without going on the roof.
What is the difference between traditional roofing felt and breathable membrane?
Traditional bitumen-based roofing felt is non-breathable — it creates a sealed layer but can trap moisture in the roof void, promoting timber rot over time if ventilation is inadequate. Modern breathable roofing membranes allow water vapour to escape outward while remaining waterproof. They are now standard on new builds and most reroofing jobs, carry 50-year design lifespans, and can often be installed without the separate tile batten ventilation requirements that traditional felt demands.
Can roof felt be replaced without removing the tiles?
No. To access and replace the underlay on a pitched roof, the tiles must be carefully removed, the old felt stripped from the rafters, new membrane installed and lapped correctly, and the tiles reinstated. There is no way to insert new felt beneath existing fixed tiles. Any contractor claiming otherwise should be treated with extreme caution.
Does replacing roof felt include replacing the tiles?
Not automatically. When tiles are removed to access the felt, a roofer will check each tile for damage and replace any that are cracked or broken. A full tile replacement is a separate cost. If a significant proportion of tiles are damaged, the roofer should flag this in their quote and provide a revised total. Always ask your roofer to confirm in writing exactly what is and is not included.
How long does roof felt last?
Traditional bituminous felt has an expected lifespan of 15–20 years, though it often fails earlier in exposed or poorly ventilated roofs. Modern breathable membranes are typically rated to 50 years or more when correctly installed. Concrete interlocking tiles can last 30–50 years; natural slate 80–100 years. The felt is usually the first layer to fail on an older roof — meaning many UK homes have tiles that are still serviceable over felt that has already deteriorated.
Ready to get quotes for your roof felt replacement?
If you are a roofer handling re-felt and re-roof jobs and want more of these enquiries coming directly to you — not through lead platforms — a free visibility audit shows you exactly where the opportunity is in your area.
Get Your Free Visibility Audit →