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CMW Roofing in Flat Roof Repair Southampton

CMW Roofing & Renovations

Flat Roof Repair
in Southampton

We repair and install felt and GRP flat roofs across Southampton. If your flat roof is leaking, we will inspect it and recommend a repair or replacement.

Felt and GRP flat roofs Leak repairs and overlays Garages, extensions and commercial £5m insured
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Our Roofing Services

We work on flat roof repairs and new installations. For pitched roofing, visit roofing services in Southampton. If you need urgent help, see roof repairs.

Flat roofs are common on garage roofs, rear extensions, bay windows, porches and single-storey additions across Southampton. The most frequent failure points are the laps on felt systems (where layers overlap and eventually lift) and at the junctions with walls, parapets and upstands.

When a felt flat roof is failing, we assess whether a repair is viable or whether full replacement is a better investment — we will always give an honest answer on this.

Our preferred replacement system is GRP fibreglass, which creates a seamless, jointless surface that eliminates the lap failure issues of felt systems and carries a 20-year manufacturer guarantee. We also repair existing GRP systems where the surface is fundamentally sound but has localised damage.

If you are not sure which option is right for your flat roof, call us for a free inspection and written assessment.

We carry out flat roof work across Southampton and Hampshire including Portsmouth, Fareham, Eastleigh, Winchester and surrounding areas. All flat roof installations include a written workmanship guarantee and we use materials from reputable manufacturers with their own guarantees. For a free, no-obligation assessment of your flat roof, call or message us today.

What we cover

Flat roof leak repairs

Identify and fix common issues like splits, failed joints and ponding water.

Felt flat roofing

Repairs, overlays and new felt installations for garages, extensions and dormers.

GRP flat roofing

GRP repairs and new GRP systems with clean edges and durable finishes.

Repair vs replacement

We will tell you when a repair makes sense and when a new flat roof is the better option.

Related pagesRoofing Southampton New roofs Roof repairs

Areas we cover

We cover Southampton and nearby areas including Shirley, Bitterne, Portswood, Woolston, Eastleigh, Chandlers Ford, Hedge End, Totton, Romsey and Netley.

If you are not sure whether we cover your location, call or message and we will confirm.

FAQs

Can a flat roof be repaired rather than replaced?
Often, yes. It depends on the age and the condition of the deck and existing system. We will inspect and advise.
What flat roof systems do you work with?
We work with felt roofing, GRP (fibreglass), and liquid plastic flat roofing systems. Each system has its own strengths, and we’ll recommend the most suitable option based on the condition of the roof, the building type, and long-term durability.
How long does a flat roof repair last?
That depends on the fault and the system. We explain expected life and options before starting work.
Do you install new flat roofs as well?
Yes. We carry out both flat roof repairs and full new installations.
How much does a flat roof repair cost in Southampton?
It depends on the size and the system — a small felt patch is far less than a full GRP overlay or replacement. We give a free written quote before any work starts, so you know the cost up front with no surprises.
Do you cover flat roofs across all Southampton postcodes?
Yes. We repair and replace flat roofs on garages, extensions and dormers across the SO14 to SO19 districts and the surrounding Hampshire area.

Get a free quote

Call or message for a free quote and a quick response. Emergency repairs available.