Flat Roofing Sheffield
Garage Roof Replacement Sheffield: Costs, Timescales & When to Refelt vs Replace
In short: A single-garage refelt in Sheffield costs £300–£700; a full replacement runs £700–£1,500. Refelt when the deck is sound and damage is surface-level. Replace when the deck is rotten, you’ve had repeat leaks, or the roof is over 15 years old. Most jobs take one to two days.
By the AJR Roofing Team — Published
Sheffield’s older housing stock — terraced rows in Walkley, semis in Dore, post-war estates across Parson Cross — means a lot of garages, and most of them have flat felt roofs that were laid 20 or 30 years ago. When a garage roof starts leaking, the question is almost always the same: refelt it, or replace the whole thing?
The honest answer depends on what’s underneath the felt, not just what it looks like on top. This guide explains the costs, the decision-making process, and what to expect from a Sheffield roofer. For a broader look at flat roof options, see our flat roof replacement service in Sheffield.
What does garage roof replacement actually involve?
Most garage flat roofs in the UK are built on a timber deck — chipboard or tongue-and-groove boarding — laid over joists and covered in layers of mineral felt. Over time, the felt degrades, the deck absorbs moisture, and joints start to let water through.
Refelting strips off the old felt and lays fresh material on the existing deck, assuming it’s structurally sound. Full replacement goes further: old covering and decking are stripped completely, any rotten boards are replaced, and the roof is rebuilt from the joists up with new decking and a new covering.
According to MyBuilder’s roofing cost guide, standard mineral felt has a design life of 10–15 years, while high-performance torch-on felt can reach 20 years under good conditions. If your garage roof is that age and leaking, the deck has almost certainly been taking water damage — and refelting onto a compromised deck just pushes the problem further down the line.
Garage roof replacement costs in Sheffield (2026)
| Job | Typical Cost (Sheffield 2026) | Timescale |
|---|---|---|
| Refelt — single garage (~16 m²) | £300–£700 | 1 day |
| Refelt — double garage (~30 m²) | £550–£1,100 | 1–2 days |
| Full replacement — single garage | £700–£1,500 | 1–2 days |
| Full replacement — double garage | £1,200–£2,500 | 2–3 days |
| Rotten deck boards (additional) | £50–£150 per board | Included |
These figures assume standard access and no major structural issues. Garages built against a boundary wall, or with difficult access for a scaffold tower, may cost more. Always ask the roofer to price the deck separately so there are no surprises once the old felt is stripped.
Hidden cost warning: A £400 refelt can become a £1,200 job if stripping reveals rotten decking throughout. A reputable roofer will flag this on inspection — be wary of anyone who quotes without checking the deck condition first.
Refelt or full replacement: how to decide
Refelt is the right call when: the deck feels firm and solid underfoot, the leak is limited to one area, the felt is surface-cracking or bubbling, and the roof is under 12–15 years old.
Full replacement makes more sense when: the deck feels spongy or gives way under foot pressure (wet rot in the OSB or chipboard), you’ve patched the same spot more than once and it keeps leaking, the roof is over 15 years old and leaking in multiple places, or you can see daylight through the boarding from inside the garage.
A refelted compromised deck just gives you 12–18 months before the weakened boards cause the new felt to split in the same places. The deck is the structural substrate — if it’s gone, the covering will fail regardless of quality.
If you’re weighing up felt versus other flat roof materials for a full replacement, our guide to EPDM, GRP and felt flat roofing in Sheffield runs through the long-term cost and lifespan comparison.
Signs your garage roof needs replacing — not just patching
- Soft or spongy deck — press down firmly at the edges and corners. Any give means rot has set in.
- Repeat leaks in the same spot — two repairs in the same place usually means the issue isn’t surface-level.
- Widespread cracking or lifting — small splits at joints are normal ageing; felt lifting across most of the surface has given up.
- Pooling water after rain — if water sits for more than 48 hours, drainage is blocked or the deck has sagged.
- Interior damp or staining — brown rings on the ceiling inside the garage, especially after heavy rain.
- Roof over 15–20 years old — even without visible symptoms, a pre-emptive replacement is almost always cheaper than waiting for a failure in bad weather.
How long does garage roof work take in Sheffield?
A straightforward single-garage refelt — strip old felt, inspect deck, lay new three-layer felt — is typically a one-day job. Add a day if deck boards need replacing. A double garage, or one with complex detailing around a box gutter or parapet wall, may run to two or three days. Weather matters: felt laying requires dry conditions, so AJR Roofing schedules around the forecast.
Getting a garage roof quote in Sheffield
A reliable Sheffield roofer will inspect the deck condition before quoting. Any quote given over the phone without a site visit should be treated as an estimate, not a fixed price. Ask specifically: what covering material are you recommending and why? What’s the quoted lifespan? Is rotten decking priced separately? What guarantee covers the work?
AJR Roofing carries out free, no-obligation inspections for garage roof work across Sheffield and South Yorkshire. Our complete guide to flat roof refelting costs in Sheffield covers what drives the price in more detail.
Need a garage roof looked at?
Call 07852 940350 or request a free quote — we cover Sheffield, Rotherham, Chesterfield and South Yorkshire.
Frequently asked questions
How much does garage roof replacement cost in Sheffield?
A single-garage refelt runs £300–£700; a full replacement including new decking is typically £700–£1,500. Double garages cost proportionally more. Prices vary with deck condition, covering choice and access.
How long does a felt garage roof last in the UK?
Standard mineral felt lasts 10–15 years. High-performance torch-on felt can reach 20 years. Once over 15 years old and leaking, replacement is usually more economical than patching.
Should I refelt or fully replace my garage roof?
Refelt if the deck is solid and damage is surface-level. Replace fully if the deck feels spongy, you’ve had repeat leaks in the same area, or the roof is over 15 years old and leaking in multiple places.
How long does garage roof replacement take?
A single-garage refelt is a one-day job. A full replacement — stripping, replacing rotten boards and re-covering — takes one to two days for a single garage.