Flat Roofing Specialists in Birmingham
SB Margan Roofing installs and repairs flat roofs across Birmingham and the wider West Midlands. With over 15 years of hands-on experience, we’ve worked on hundreds of flat roofs — from single-storey rear extensions in Northfield to garage conversions in Quinton and outhouse roofs across Harborne. We install three main flat roofing systems and will advise honestly on which is best suited to your property and budget.
All our flat roofing work is carried out personally by Sergiu Margan, never subcontracted. Every installation comes with a written workmanship guarantee and manufacturer product warranties where applicable. We clean up fully after ourselves and leave no mess behind.
GRP Fibreglass Flat Roofing
GRP (Glass Reinforced Plastic) fibreglass is the premium flat roofing option and our most popular system for new installations. The roof is formed in a single seamless layer directly on your roof deck, creating a completely watertight surface with no joins, seams or overlaps to fail. A properly installed GRP flat roof will last 25 years or more with no significant maintenance required.
GRP is ideal for house extensions, bay window tops, porches and any flat roof area where appearance and longevity matter. It can be finished in a range of colours, most commonly light grey or white, and takes a hard, attractive surface that looks smart and ages well. The material is also fire-resistant and can bear foot traffic, making it suitable for accessible flat roofs.
The installation process typically takes one day for a standard extension roof. We prepare and seal the deck, apply the glass fibre matting and then topcoat with GRP resin. The curing process completes within hours and the roof is fully waterproof the same day.
EPDM Rubber Flat Roofing
EPDM (Ethylene Propylene Diene Monomer) rubber is a cost-effective, highly durable flat roofing membrane that has been the industry standard in North America for decades and is now widely used in the UK. It offers a lifespan of 20 years or more, excellent resistance to UV degradation, temperature fluctuations and pooling water, and is particularly well-suited to larger flat roof areas.
For garage roofs, large outbuildings and industrial flat roofs, EPDM offers outstanding value for money. It’s installed as a single bonded sheet, eliminating the joints and overlaps that are the weak points of traditional felt systems. It also performs well in standing water, which is common on flat roofs that can’t be perfectly levelled.
Felt Flat Roofing
Traditional torch-on felt is a well-established flat roofing system that, when installed correctly using quality materials, provides a solid and cost-effective solution. Modern torch-on felt systems use reinforced bitumen membranes (RBM) that offer improved performance over older felt systems, typically lasting 15–20 years.
Felt is often the most economical option for budget-conscious clients and is perfectly adequate for garages, outbuildings and extensions where longevity is less of a priority. We use high-quality products and install to manufacturer specifications on every job.
Applications
We install flat roofs on a wide range of structures across Birmingham:
- Single and double-storey rear extensions
- Side return extensions
- Garage roofs (single and double)
- Outbuildings and sheds
- Bay window tops and porch roofs
- Dormer cheeks and tops
- Flat sections of pitched roofs
Signs Your Flat Roof Needs Attention
Flat roofs should be inspected periodically, particularly after winter. Common signs of failure include:
- Blistering or bubbling of the roof surface
- Visible cracking, splitting or crazing of the top surface
- Ponding water that doesn’t drain within 48 hours
- Damp patches on the ceiling beneath the flat roof
- Moss or weed growth through the covering
- Felt edges lifting away from the fascia or upstand
Many flat roofs can be repaired rather than replaced entirely, particularly if the deck itself is sound. We always assess honestly and will give you both options where applicable.
Repair vs Replacement
Not every flat roof problem requires a full replacement. If the roof deck is in good condition and the issue is localised, we can often carry out a targeted repair using compatible materials. However, if the covering is reaching the end of its lifespan — particularly with older felt systems — or if there are multiple failure points, a full replacement is usually more cost-effective in the long run and prevents recurring call-out costs.
When we carry out a survey, we’ll give you an honest assessment of the condition and tell you clearly whether repair or replacement makes more sense, along with the pros and cons and indicative costs for each.
Frequently Asked Questions
How long does a GRP flat roof last?
A properly installed GRP flat roof will typically last 25–30 years. GRP is one of the most durable flat roofing systems available and, when maintained correctly (periodic cleaning, no sharp impacts), requires very little attention during its lifespan.
Is a flat roof suitable for a house extension?
Yes — modern flat roofing systems like GRP fibreglass are widely used on house extensions and perform very well. The key is correct installation with appropriate falls to encourage drainage. We design and install all our flat roofs with proper drainage in mind.
How much does a flat roof replacement cost?
Costs vary depending on the size of the roof, the system chosen and the condition of the existing deck. As a rough guide, a standard single-storey extension GRP flat roof typically starts from around £800–£1,200 for smaller areas. We provide free, no-obligation written quotes for all work.
Do I need planning permission for a flat roof?
Re-roofing or replacing an existing flat roof generally falls under permitted development and doesn’t require planning permission, as long as you’re using similar materials. If you’re building a new structure, permitted development rules apply to the structure itself. We can advise on this when we visit.