Flat Roofing in Newmarket - Materials and Options Explained

Expert Flat Roofing
in Newmarket

Flat Roofing Options for Homes in Newmarket

Flat roofs on domestic properties - garages, extensions, dormers and bay windows - can be covered in more than one type of material. When a flat roof needs repairing or replacing, homeowners in Newmarket are often told by one roofer to go with felt and by another to go with rubber, without a clear explanation of why. This page sets out the real differences so you can make an informed decision.

We are based in Bury St Edmunds and carry out flat roof repairs and replacements for homeowners in Newmarket and the surrounding area. We work with traditional torch-on felt and EPDM rubber membrane, and we will always explain which material we are recommending for your specific roof and why.

The Two Main Materials for Domestic Flat Roofs

For domestic flat roofing in the UK, the two materials you are most likely to be quoted for are torch-on felt (also called modified bitumen felt) and EPDM rubber. Each has genuine advantages and genuine drawbacks. There is no single right answer - the best choice depends on your budget, your roof size, the condition of the deck and how long you intend to stay in the property.

Torch-On Felt - Honest Pros and Cons

Torch-on felt is a multi-layer system. A vapour control layer goes down first, then an insulation board if the spec calls for it, then a base layer of bitumen felt, and finally a mineral-faced cap sheet that forms the weather surface. Each layer is bonded with a gas torch - hence the name. It has been the standard domestic flat roofing material in the UK for decades, and there are good reasons it is still widely used.

Advantages of torch-on felt:

• Lower material cost than EPDM, so the upfront price is generally lower for smaller roofs.
• Widely understood by roofers - a straightforward installation when done properly.
• Good for roofs with lots of penetrations (pipes, vents, rooflights) because the felt can be cut and bonded tightly around complex shapes.
• Repairs are relatively easy to carry out - a patch can be torched over a damaged area without replacing the whole surface.

Disadvantages of torch-on felt:

• Shorter lifespan than EPDM. A well-installed torch-on felt roof typically lasts 10-15 years. After that, the bitumen dries out and becomes brittle, leading to cracking and water ingress.
• More vulnerable to thermal movement. Felt expands and contracts with temperature changes, and over time splits develop at edges, corners and upstands where movement is concentrated.
• Susceptible to blistering if moisture is trapped during installation or if the vapour control layer is missing.
• The seams between sheets are potential weak points. Correct bonding technique is critical.

EPDM Rubber - Honest Pros and Cons

EPDM (ethylene propylene diene monomer) is a synthetic rubber membrane that is now the most widely recommended material for new domestic flat roofs. It comes in large sheets, which means a garage or extension roof can often be covered with a single piece that has no seams at all. It is fully adhered to the deck using a specialist adhesive rather than heat.

Advantages of EPDM:

• Long service life. EPDM membranes typically last 30-50 years when properly installed and maintained, substantially longer than felt.
• Excellent flexibility. EPDM remains pliable in cold weather and does not become brittle, which means it handles thermal movement without splitting at edges and corners.
• Fewer seams means fewer potential failure points. A single-sheet installation on a straightforward garage or extension roof is inherently low-risk.
• Lighter than a multi-layer felt system, which puts less load on the structure.
• Performs well over a wide temperature range, from hard frost to summer heat.

Disadvantages of EPDM:

• Higher material cost than felt, so the upfront price is typically higher, particularly on larger roofs.
• Requires careful surface preparation. The deck must be clean, dry, flat and sound before the adhesive goes down. Any contamination or moisture in the deck can compromise the bond.
• Repairs to punctures or tears require a specific EPDM repair kit or patch. A general felt patch will not adhere properly to a rubber membrane.
• On roofs with many penetrations, detailing around each pipe or vent requires patience and precision. A poorly detailed penetration is a likely leak point.

What About Felt Versus EPDM on Cost?

Flat roof replacement costs in the UK vary with roof size, deck condition and material choice. As a general guide, torch-on felt typically runs in the range of £50-£80 per square metre installed, while EPDM typically runs £70-£100 per square metre installed. Those are material-and-labour figures for a replacement on a sound deck. If the deck needs partial or full replacement, add the cost of boards and extra labour. A small garage roof of around 15-20 square metres will cost considerably less in total than an extension roof of 30-40 square metres, so it is always worth getting a specific quote for your actual roof rather than relying on rough figures.

It is also worth thinking about whole-life cost rather than just upfront price. A felt roof that costs £1,200 and needs replacing in 12 years will cost more over 25 years than an EPDM roof that costs £1,600 and runs for 35 years with minimal maintenance.

Does the Deck Condition Change the Decision?

Yes, significantly. Both materials need a sound, dry, flat deck to perform well. Plywood and OSB decking boards that have been waterlogged will be soft, delaminated and rotten in patches. Those boards must be replaced before any new membrane goes on. Laying new felt or rubber over a failing deck is a false economy - the membrane will not bond properly to a soft or uneven surface, and the deck will continue to deteriorate beneath it.

Before accepting any quote, ask the roofer whether they have walked the deck and checked for soft spots, and whether their price includes replacing any damaged boards. A roofer who quotes without checking the deck is guessing at the cost.

Insulation - Worth Including?

If your flat roof is above a heated room, insulation is worth serious consideration when you are already replacing the surface. Adding insulation at the time of a full replacement costs far less than coming back to retrofit it later, and it can noticeably reduce heat loss through the roof. A warm-roof build-up - where the insulation sits above the deck and below the membrane - is the most thermally efficient option and reduces the risk of condensation within the structure.

What to Ask When Getting Quotes in Newmarket

• Which material are you recommending, and why does it suit this roof specifically?
• Have you walked the deck and checked its condition?
• Does your price include replacing damaged decking boards?
• How will you finish the flashings and upstands?
• Is insulation included or optional, and what build-up are you specifying?

A roofer who gives you detailed answers to those questions understands what they are doing. One who cannot explain the why behind their recommendation is worth being cautious about.

Talk to Us About Your Flat Roof in Newmarket

We cover Newmarket from our base in Bury St Edmunds. If you have a flat roof that needs attention, call us to arrange an inspection and we will give you a clear assessment of what the roof needs, what material we recommend and why, before you commit to anything.