Flat Roofing in Newmarket - Repair or Replace?

Expert Flat Roofing
in Newmarket

The Central Decision Every Flat Roof Owner Faces

A leak or a visible defect on a flat roof puts you in front of a choice: patch it, repair the affected section, or strip it back and start again. Getting that decision wrong in either direction costs money. Replace too soon and you have wasted a roof that had years left in it. Repair when replacement is overdue and you will be calling a roofer back within a season or two.

The right answer depends on the age of the membrane, the condition of the deck underneath, the nature and location of the defect, and how many repairs the roof has already had. None of those things can be judged from the ground.

When a Repair Makes Sense

A repair is the right call when the membrane is structurally sound, the deck is dry and undamaged, and the problem is a localised defect rather than general deterioration. Common repairable faults include:

• A split or blister in the felt that is isolated to one area and has not allowed sustained water ingress into the deck
• A failed lap joint where two sheets of membrane meet, provided the surrounding material is still bonded and intact
• An upstand that has lifted away from a wall or parapet, leaving a gap that water can enter
• A perished or cracked lead flashing where the membrane meets a vertical surface
• A blocked or poorly fitted outlet that has caused pooling but has not yet damaged the deck

If the repair can be carried out in a way that the new material bonds properly to the existing membrane, and if there is no underlying deck damage, a targeted repair can give many more years of trouble-free performance. It is also significantly cheaper than a full replacement in the short term.

When Replacement Is the Better Choice

Replacement becomes the sensible option when the membrane has reached the end of its serviceable life across most of its area, when the deck has absorbed moisture and started to degrade, or when a roof has been repaired multiple times and is now a patchwork of different materials bonded together in ways that create new weak points.

A saturated deck is the clearest indicator that replacement is unavoidable. Once the timber or chipboard decking has become wet and begun to soften, no surface repair will solve the problem. The moisture is trapped beneath whatever you apply on top, and the deck continues to break down. The membrane will eventually part from the surface, and any new repair will fail in the same way.

Age is also a factor. A torch-on felt roof typically has a serviceable life of around 15-20 years under normal conditions. An EPDM rubber roof, properly installed, can last significantly longer. If your existing roof is approaching or past those thresholds and is showing widespread cracking, loss of surface aggregate, or generalised softness underfoot, replacement is likely to be more economical over the next decade than repeated repairs.

The Hidden Cost of Repeated Patching

A patch repair on an ageing membrane rarely holds for long. The material around the patch is still deteriorating, and new splits or separations tend to open up nearby. Each repair call costs money, and the cumulative cost of three or four patch repairs over two or three years can approach or exceed the cost of a proper re-roof that would have sorted the problem definitively.

Before agreeing to any repair on a roof that is more than ten years old, ask the contractor to inspect the full surface and the deck. If they identify that the problem is not isolated, it is worth getting a replacement quote alongside the repair quote so you can make an informed comparison.

What a Replacement Job Should Include

A proper flat roof replacement is not simply a matter of laying a new membrane over the old one. The sequence matters, and cutting steps creates problems that show up later.

• Strip the existing membrane back to the deck, or to a sound substrate if more than one layer is present
• Inspect the deck and replace any sections that are soft, wet, or rotten
• Check and correct the drainage falls, adding firring pieces if necessary to achieve a minimum fall of 1:80
• Lay the new membrane system to the full area, including edges, upstands, and outlets
• Dress all upstands to a minimum height of 150mm and ensure outlets are properly integrated into the new surface

The choice of membrane for the replacement matters too. For most domestic garages and extensions in the Newmarket area, EPDM rubber is a strong option because of its flexibility, its seamless coverage over large areas, and its long expected service life. A good felt system using torch-on mineral felt in multiple layers is also a proven approach. The contractor should explain the choice rather than defaulting to whatever they habitually install.

Getting Quotes for Repair or Replacement

Flat roof repair costs vary widely depending on what is wrong and how accessible the roof is. A single split in an otherwise sound felt surface might cost a few hundred pounds to fix properly. A full re-roof on a typical garage of around 20-25 square metres can range from roughly £1,200 to £2,500 depending on the system chosen and the condition of the deck. On a larger extension roof the figure rises accordingly.

The only way to get an accurate figure is to have the roof inspected. Any quote given without an inspection should be treated as provisional, because the state of the deck is unknown until the old membrane comes off.

We Cover Newmarket and the Surrounding Area

Mildenhall Roofers carries out flat roofing work across Newmarket and the wider Suffolk and Cambridgeshire area, including Mildenhall, Kentford, and other nearby towns and villages. Whether you need a straightforward repair or are weighing up a full replacement, call us and we will inspect the roof properly and give you an honest assessment of which option makes sense for your situation.