Felt flat roof repairs and replacements in Amersham.
Felt is still the most common flat roof covering on older properties across Amersham and south Buckinghamshire. Three layers of bituminous felt, torch-applied or bonded with hot bitumen, over a timber deck. Simple, proven, and it works — but after 15–20 years the felt dries out, cracks, and starts letting water through.
We repair, overlay, and replace felt flat roofs across Amersham and the surrounding villages.
Call 01494 702 599 for a free survey.
Common felt roof problems
Blisters and bubbles
Moisture gets trapped between the felt layers and expands in the heat, creating bubbles in the surface. Small blisters are cosmetic. Larger ones can crack and let water in. We cut, drain, and re-seal blisters as part of a repair.
Splits and cracks along seams
The overlap where two strips of felt meet is the weak point. Over time, thermal movement opens up the seam and water gets in. We clean, prime, and re-seal failed seams — or overlay with a new top layer if the damage is widespread.
Granule loss
The mineral granules on the top layer of felt protect it from UV. Once they wear off, the exposed bitumen degrades much faster. If your felt roof looks smooth and black instead of rough and grey, it’s past its best.
Ponding water
Water sitting in low spots after rain is a slow killer. It accelerates felt degradation, encourages moss growth, and eventually finds a way through. Fixing this properly usually means re-laying the felt with a corrected fall, or replacing the roof entirely.
Repair, overlay, or replace?
Repair — localised damage, rest of the felt is still in good condition. Cheapest option, buys you a few more years.
Overlay — the existing felt is worn but the deck underneath is sound. We lay a new top layer directly over the old one. Mid-range cost, extends the roof’s life by 10–15 years.
Full replacement — the felt is beyond repair and the deck may be damaged. Strip everything off, check the timber, and start fresh with new felt, EPDM, or GRP.
We’ll recommend the right approach after surveying your roof. If a £200 repair will do the job, we’ll say so.
What it costs
| Type of work | Typical price |
|---|---|
| Seam repair or blister fix | £150–£400 |
| Felt overlay (garage) | £600–£1,000 |
| Felt overlay (extension) | £800–£1,500 |
| Full felt replacement (garage) | £900–£1,500 |
| Full felt replacement (extension) | £1,200–£2,500 |
Should I replace felt with felt, or upgrade?
If budget is tight, new felt on a sound deck is a perfectly reasonable choice — it’ll give you another 15–20 years. But if you can stretch to EPDM rubber, you get twice the lifespan (30–40 years) for roughly 20–30% more cost. We’ll quote both options so you can compare.
Common questions
How long does felt roofing last?
15–20 years for a three-layer torch-on system. High-performance felts at the top end can push 25 years.
Is felt roofing still a good option?
For budget-conscious replacements, yes. It’s proven, repairable, and widely understood. For longer-term value, EPDM or GRP are better investments.
Can you lay new felt over old felt?
Sometimes — if the existing surface is flat and the deck is sound. This is an overlay, and it’s cheaper than a full strip-and-replace. We’ll tell you if it’s suitable after a survey.
Where we cover
We repair and replace felt roofs across Amersham, Old Amersham, Little Chalfont, Chalfont St Giles, Chalfont St Peter, Great Missenden, Chesham, Beaconsfield, Penn, Holmer Green, and Hazlemere.
Get a free quote
Phone: 01494 702 599
Email: info@amershamroofers.co.uk