Flat Roofing in Mildenhall - Materials, Options and Honest Pros and Cons

Expert Flat Roofing
in Mildenhall

Why the Material You Choose Matters More Than Most People Realise

When a flat roof needs replacing, the material decision shapes everything that follows - how long the roof lasts, how it handles standing water, how easy it is to repair in future, and what you pay now versus over the life of the roof. There is no single right answer for every property, but there is usually a best answer for your specific situation.

We install flat roofs in Mildenhall and across the surrounding area using two main systems: EPDM rubber membrane and traditional built-up felt. Here is an honest account of both.

EPDM Rubber Membrane - The Modern Standard

EPDM (ethylene propylene diene monomer) is a single-ply rubber membrane, typically 1.2mm or 1.5mm thick, bonded to the roof deck in either a single sheet or large sections with very few joins. It has become the most widely specified system for domestic flat roofs over the last fifteen years.

What EPDM Does Well

• Handles thermal movement well - it stretches rather than splitting when the roof deck expands and contracts with temperature
• Factory-welded or bonded lap joints reduce the number of seams where leaks can start
• Resistant to UV degradation - the material does not become brittle in the same way that older felt does
• Manufacturers typically quote service lives of 20 years or more under normal conditions, though actual lifespan depends on how well it is installed and maintained
• Relatively straightforward to repair if it is punctured or a seam opens - a compatible patch or seam tape correctly applied gives a reliable fix
• Can be laid in cooler conditions than felt, giving more flexibility in the working season

Where EPDM Has Limitations

• Material and installation costs are higher than basic felt - expect to pay more upfront
• Repairs using incompatible adhesives or the wrong patch material can cause the membrane to lift or bubble - it must be repaired with the correct system products
• On very large or complex roofs with many penetrations, getting the detailing right at each upstand, outlet, and pipe collar demands careful workmanship
• Dark in colour, which can absorb heat in summer - though this rarely causes structural problems on domestic roofs

For most extensions and garages in Mildenhall, EPDM is the system we recommend when the budget allows. The reduced likelihood of seam failure and the longer working lifespan make it a more economical choice over ten or fifteen years than repeatedly repairing or re-covering a felt roof.

Traditional Felt - Built-Up and Torch-On Systems

Felt has been used on flat roofs for well over a century. Modern felt systems are a significant improvement on the old mineral-surface three-layer built-up felt of the 1970s and 1980s, but the basic principle is the same: multiple layers of bitumen-based felt are bonded together, usually by torching (using a gas burner to melt the underside of each layer as it is rolled out).

What Felt Does Well

• Lower material cost than EPDM, which reduces the upfront price of a re-cover
• Well-understood by virtually every roofer, so repairs can be carried out by a wide range of contractors if needed in future
• The torch-on method creates a fully bonded, monolithic surface with good resistance to wind uplift
• Heavy-duty cap sheet (the top layer) with a mineral surface reflects some solar radiation and resists foot traffic reasonably well

Where Felt Has Limitations

• More seams and laps than a single-piece EPDM sheet, giving water more places to find a way in if workmanship is not careful
• Bitumen becomes brittle over time, particularly where the roof is exposed to frost repeatedly - surface cracking and splitting at seams is the most common failure mode
• Requires dry, reasonably warm conditions to lay correctly - torch-on work in cold or damp weather can produce poor bonds
• A standard felt re-cover on a domestic roof might realistically last 10-15 years; some last longer, some less, depending on quality of materials and installation

What About Existing Felt on Older Roofs?

Many garages and extensions still carry the original mineral-surface felt from when they were built. If that felt is cracking, losing its surface, or has been patched more than once, laying new felt directly over the top is not good practice - it traps moisture between layers and the new covering has no solid, dry base to bond to. The old material should come off, the deck should be inspected, and any rotten or wet boarding should be replaced before the new system goes down.

Insulation - an Option Worth Considering When Re-Covering

When a flat roof is being stripped and re-covered anyway, it is a practical point to think about upgrading the insulation at the same time. Adding a layer of rigid insulation board above the deck (a warm roof construction) improves thermal performance and reduces condensation risk within the roof build-up. It adds to the cost, but doing it as part of a re-cover is considerably cheaper than returning to the roof later. Ask any roofer you speak to whether your existing build-up is a warm or cold roof construction, and what the options are for improvement.

Drainage and Falls - the Detail That Makes or Breaks Any System

The best membrane in the world will not perform if the roof does not drain properly. A correctly formed flat roof has a minimum fall of 1:80, draining to an outlet or into a gutter. On extensions and garages, the outlet position and gutter run should be checked at the survey stage. If the existing deck has settled and lost its fall, tapered insulation can be used to restore it. This adds cost but avoids the single biggest cause of flat roof failure: standing water.

Typical Costs in Mildenhall

A felt re-cover on a standard single garage or small extension (around 15-25 square metres) typically costs £900 to £1,800 installed. An EPDM re-cover of the same area generally runs £1,400 to £2,500. Deck repairs, tapered insulation, or a more complex roof shape with multiple upstands and outlets will push costs above those figures. These are typical UK ranges; your actual price depends on what the survey reveals about the deck condition and drainage.

If you have a flat roof in Mildenhall that needs attention, call us for a roof survey and we will give you a clear breakdown of which system suits your roof and what the job will cost.

We Cover Mildenhall and the Wider Area

Our base is in Ely and we take on flat roofing work across Mildenhall and the surrounding communities. Call us to confirm we cover your postcode.