BS 8217 compliant torch-on, single ply, and GRP systems — installed to last 20+ years with our 15-year guarantee and insurance-backed protection.
The majority of flat roof failures we see stem from the same root causes: inadequate falls, poor lap adhesion, incorrect detailing at upstands and outlets, and — on warm roof constructions — missing or poorly installed vapour control layers causing interstitial condensation.
At Ikon Roofing, every flat roof installation is designed and built to eliminate these failure points. We don't just lay felt — we engineer a system that's compliant with BS 8217:2005 and BS 6229, with correct falls, proper drainage, and lead detailing that will perform for decades.
Our go-to flat roofing system is the Fix-R 20 three-layer torch-on built-up felt system. It's a proven, high-performance specification that we've installed across hundreds of properties in Kent and South East London.
For projects where a single ply solution is more appropriate — larger commercial areas, green roof substrates, or client preference — we install mechanically fixed or fully adhered EPDM, TPO, and PVC membrane systems. Typical membrane thickness is 1.2mm–1.5mm, with hot air welded seams (TPO/PVC) or adhesive bonded joints (EPDM).
GRP (glass reinforced polyester) systems are ideal for smaller flat roof areas, balconies, and bay tops where a seamless, rigid finish is desirable. We install to manufacturer specification with correct edge trims and upstand detailing.
We'll always assess whether an overlay is viable before recommending a full strip. An overlay onto existing felt is only appropriate where the existing substrate is sound and the existing felt adhesion is confirmed via cut testing. We'll never overlay onto single ply — the chemistries are incompatible.
If the existing deck shows signs of moisture damage (readings above 20% on a pin-type meter), or if the existing felt has debonded, a full strip back to the deck is the only proper approach. For minor issues that don't require a full replacement, our roof repair service can often extend the life of an ageing flat roof by several years.
Not sure whether your flat roof needs replacing? Read our guide on how long a flat roof should last and the 7 signs your roof needs replacing.
On warm roof build-ups (insulation above the deck), a vapour control layer (VCL) is mandatory. We calculate U-values and perform condensation risk analysis per BS 5250 to ensure the construction is thermally and hygroscopically sound. Getting this wrong leads to interstitial condensation — one of the most common and most destructive flat roof failures we encounter.
Common questions about flat roof installations, repairs, and maintenance.
A properly installed torch-on felt system like the Fix-R 20 has an expected service life of 20–25 years. Single ply membranes (EPDM, TPO) typically last 25–30 years. GRP fibreglass can last 30+ years. Lifespan depends heavily on correct installation, adequate falls, and regular maintenance.
Flat roof costs vary depending on the system, size, and condition of the existing deck. As a rough guide, a torch-on felt system for a typical domestic extension starts from around £80–£120 per square metre including all materials, labour, and guarantee. We provide detailed written quotes after a free on-site survey.
An overlay is only appropriate where the existing substrate is sound and the existing felt adhesion is confirmed via cut testing. If there's moisture damage or the felt has debonded, a full strip is the only proper approach. We'll always assess honestly and recommend the right solution — we won't overlay a roof that needs stripping.
Every flat roof installation comes with three layers of protection: a 15-year workmanship guarantee from Ikon Roofing, a 15-year manufacturer-backed materials warranty from Fix-R, and a 10-year insurance-backed guarantee (IBG) — meaning you're covered even if the company ceased trading.
Torch-on felt is a multi-layer bituminous system applied with a gas torch — it's our preferred system for domestic flat roofs due to its proven track record and cost-effectiveness. Single ply (EPDM, TPO, PVC) is a single membrane sheet, either mechanically fixed or fully adhered. It's often specified on larger or commercial projects. Both deliver excellent long-term performance when installed correctly.
Yes. We cover the full DA, BR, SE, ME, and TN postcode areas — including Sidcup, Orpington, Bromley, Dartford, Medway, Rochester, Welling, Chislehurst, and surrounding towns. Free site surveys are available across our full service area.
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Real reviews from homeowners across Kent and South East London.
