Standing in a drafty loft, torchlight flickering off old beams, you notice droplets on the dusty insulation. A closer inspection points to torn roof felt, but the rain outside refuses to let up. It’s a classic dilemma: can you address roof felt problems from inside your loft, without braving ladders and slippery roof tiles?
This question isn’t just about convenience. It’s about safety, cost, and the long-term health of your home.
What Exactly is Roof Felt?
Roof felt, often called sarking felt, is a membrane laid between your roof tiles and the roof structure.
It serves several key purposes:
- Acts as a secondary barrier against wind-driven rain and snow.
- Reduces drafts and slows down heat loss.
- Helps direct any water ingress into gutters, away from your home’s interior.
Most British homes built after the 1930s use some form of roof felt, though the materials have changed over the years. Early felts were bitumen-based, whereas modern versions might be lightweight, breathable membranes.
Why Roof Felt Gets Damaged
Several issues can cause roof felt to fail over time:
- Age and weathering — older felts tend to become brittle and crack.
- Condensation forming on the cold side of the felt, especially in poorly ventilated lofts.
- Damage during maintenance or from misplaced foot traffic in the loft.
- Rodents or birds getting into the roof space.
- Fallen tiles, which can tear the membrane.
Spotting the source is the first step. Sometimes the felt sags, splits, or is missing entirely along the eaves. Each scenario dictates how successful a loft-based repair might be.
Repairing Roof Felt: Loft vs. Roof Access
Can you fix it from inside, or must you go outside? Here’s a quick comparison:
Approach | Pros | Cons |
|---|---|---|
From inside the loft | Avoids working at height. Weather less of a concern. Faster for small repairs. | Hard to reach felt above tight rafters. Won’t address missing tiles. May not provide a lasting seal. |
By accessing the roof | Full access to the damaged area. Easy to replace large sections. | Requires ladder, scaffold, or professional help. Weather dependent. Higher risk of falling. |
Many are drawn to the idea of a quick, safe fix from within the loft. The reality: it is sometimes possible, but there are clear limits.
What Can Be Repaired from Inside?
Small rips, holes, or minor splits in the roof felt can occasionally be patched from inside the loft. The success of such repairs depends on:
- The location: easy to reach flat sections are the most straightforward.
- The extent of damage: anything larger than a few centimetres is challenging.
- The condition of surrounding felt: if the area is brittle and flaking, patching may fail.
Common interior repair tasks include:
- Applying bitumen-based felt repair tape over splits.
- Smoothing on cold applied roofing mastic for tiny holes.
- Patching with offcuts of breathable membrane, fixed with staples and sealed at the edges.
Problems hidden near the eaves or under overlapping rafters are much tougher to deal with from inside.
Step-by-Step Guide: Patching a Minor Tear from Inside
- Locate The Issue Move or roll back any insulation and check for water staining. Use a torch for a thorough inspection.
- Prepare The Area Remove dust and cobwebs. Dry the felt if it’s damp.
- Trim And Clean Up Torn Edges If the felt is fraying, trim away loose strands for a flat surface.
- Apply The Patch Or Tape Use repair tape (bitumen-based) or a felt patch cut slightly larger than the tear. Press down firmly.
- Seal The Edges Apply roofing mastic around the patch to prevent future water ingress. Smooth down so there are no gaps.
- Reinsulate Replace any insulation you removed, ensuring it’s dry.
Such repairs are quick and inexpensive, but don’t address wider problems like rotten rafters or missing tiles.
Should You Attempt a DIY Inner Loft Repair?
Think carefully before reaching for your toolbox. Ask yourself:
- Is the damage very small and easy to reach?
- Are the roof’s tiles intact?
- Can I safely work in the loft, with secure footing?
- Am I comfortable using protective equipment and handling mastic or adhesive products?
If any of those get a ‘no’, it’s time to call in a roofer.
DIY repairs make sense for neat, shallow tears. Anything more — or signs of wood rot — require expert attention.
What Problems Will a Loft-Based Patch NOT Solve?
It’s easy to become overconfident after a neat interior patch. However, certain issues always demand proper, external repair:
- Felt that has deteriorated over wide areas.
- Tears or holes near the eaves, where felt guides water into the guttering.
- Missing or slipped tiles above the damaged felt.
- Rotten or sagging timbers beneath the felt.
- Large or repeated leaks that have soaked through insulation and ceiling plaster.
In many cases, water marks on your loft’s insulation are a sign that the tiles above need replacing or repositioning, not just the felt.
When is Professional Help Absolutely Necessary?
Some situations are simply too complex or risky for DIY repairs. Consider contacting a roofer if:
- The leak is persistent, worsening, or coming from multiple spots.
- There’s structural damage to the rafters or trusses.
- You spot daylight through the roof above.
- Large parts of the felt are hanging loose or are absent.
- The area is close to electrical wiring or the loft hatch, posing extra risk.
Professional roofers can:
- Lift roof tiles and renew entire strips of felt.
- Replace rotten wood.
- Fit eaves trays or breathable membranes for improved ventilation.
- Provide guarantees for their work.
Safety should always outweigh convenience.
Is Modern Roofing Felt Different?
Traditional bitumen felts, common in British homes up to the 1980s, tend to become brittle and tear under stress. Newer ‘breathable’ felts are lighter, resist decay, and are easier to patch (but often less sticky).
Some homes combine felt with plastic eaves trays to prevent the sagging often seen where old felt disintegrates. Patching a breathable membrane requires different adhesives — cold-applied mastic is often suitable, but check the manufacturer’s guidance before applying anything.
Preventing Further Damage
Once you’ve patched the felt or had a professional make repairs, keep your loft in order:
- Clear loft insulation from the eaves, ensuring air flows to remove condensation.
- Regularly check for moths, rodents, or bird nests, as these can worsen holes.
- Schedule a roof inspection every couple of years, or after violent storms.
- Never store heavy items directly on roof timbers or the felt.
What’s left unchecked today can become a major leak next winter.
Common Questions about Roof Felt Repairs
Do I need to replace all the felt if there’s a small tear? No. Small, isolated tears can be patched. Only widespread damage needs a full re-felt.
Is roof felt breathable? Newer types are, allowing moisture to escape the loft. Older, black bitumen felts are not.
How do I know if water stains in the loft are from felt damage? Check for missing or slipped tiles directly above the stain. If none are visible, suspect the felt.
Can I use regular duct tape or tarpaulin to fix the felt? No. Use dedicated roofing repair tapes or patches for a proper seal.
Should I add more insulation to keep water away from the ceiling? Insulation does not stop leaks. Focus on waterproofing instead.
Typical Costs: DIY vs Professional
Cost often dictates the first step. Here’s a comparison for patching 2–3 minor felt tears:
Task | DIY Materials (£) | Professional Fix (£) |
|---|---|---|
Repair tape + mastic | 12–25 | – |
Professional visit to patch felt | – | 80–200 |
Full re-felt (average 3-bed semi) | – | 1,800–4,500 |
For repeated issues, investing in a full re-felt proves cheaper in the long run.
A Safer, Drier Home
Tackling roof felt fixes from the loft can be tempting, especially on miserable rainy days. While it’s suitable for minor, accessible faults, the bigger the issue, the stronger the case for skilled help.
Next time you notice stains on your insulation or a drip above the attic hatch, remember: a well-maintained roof felt is silent, invisible, and utterly vital for your home’s well-being. A patch inside the loft might buy you time, but never skip regular checks or riskier repairs if your home’s future is at stake.
