Our strict, methodical installation process for flat metal roofs ensures the Multi-Dex system is as effective as possible for your home.

For more information on this or a free on-site inspection, feel free to contact us.

Step 1: Boarding

  • Clean and prepare your roof for new waterproofing.
  • Supply and fit a 25mm insulation 16 dv Multi-Board to the existing roof.
  • Supply and fit a 3.2mm support board onto the insulation panels.

Multi-board features:

  • Made from 16 DV (Density Volume) polystyrene board.
  • Class B1 fire retardant material (DIN4102 tested).
  • Offers a 10°C differential in ambient temperature
  • 100% sound insulation from weather-noise.

Step 2: Flashing

  • The gutter overhang is cut back and we fit a 90 degree metal flashing.

Step 3: Torch on

  • Using a fusion/gas weld application method, we torch on the Multi-Dex approved 4mm waterproofing torch-on system (Derbigum or Derbit), with 75mm overlaps and 100mm cross-laps as per specification.
  • Waterproofing system is then cut, dressed and sealed into outlets.

Multi-dex approved 4mm Membrane features:

  • High-performance synthetic fibre dual-reinforced (polyester and glass).
  • Polymer modified-bitumens coated.
  • UV degradation and heat shock resistant, for extreme durability.
  • Only fire rated torch-on system in the industry

Step 4: Sealing off

  • Seal off the system by torching-on the 4mm waterproofing system onto the parapet walls, 75mm cross laps and gutter junctions

Step 5: Coating

  • Apply a specially formulated acrylic aluminium coat to the entire system, to maximise UV stabilisation and ensure its longevity.