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Flat Roofs

GRP fibreglass and torch-on systems — seamless, low-maintenance, and guaranteed.

GRP fibreglass flat roof installation

Modern Flat Roofing Solutions

Old felt flat roofs leak repeatedly. GRP (glass-reinforced plastic) fibreglass is the modern standard — seamless, incredibly durable, and virtually maintenance-free. M3 Roofing installs fibreglass systems on garages, house extensions, commercial units, and bay windows with a 25-year manufacturer guarantee as standard.

We also carry out torch-on (SBS modified bitumen) systems where specified, and repair or overlay failing existing flat roofs where a full replacement isn't necessary.

Flat Roof Systems We Install

  • GRP fibreglass — seamless, 25yr guarantee
  • Torch-on modified bitumen SBS felt systems
  • Flat roof patch repairs and overlay systems
  • Insulated warm roof build-ups for energy efficiency
  • Upstands, trims, and perimeter detailing
  • Roof lights and drainage integration

Why GRP Over Traditional Felt?

Traditional Felt
  • Lifespan 10–15 years
  • Seams and joins vulnerable
  • Prone to ponding and cracking
  • Regular maintenance needed
GRP Fibreglass
  • Lifespan 25+ years
  • Fully seamless surface
  • Resistant to ponding and impact
  • Virtually maintenance-free

Our Process

  1. 1
    Survey & Quote

    We assess the existing substrate, falls, drainage, and any structural issues.

  2. 2
    Strip & Prepare

    Old covering removed, deck inspected, and any rotten boards replaced.

  3. 3
    GRP Lamination

    Fibreglass laminate applied in controlled layers with a gel-coat topcoat.

  4. 4
    Trim & Guarantee

    Aluminium trims fitted, site cleaned, 25yr manufacturer certificate issued.

Old Flat Roof Causing Problems?

A GRP fibreglass replacement will end the leaks for good — get your free survey today.

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