Harmer Modulock is a fully engineered raised pedestal system for supporting paving slabs, timber or plywood sheet decking at varying heights from the sub-structure. Available with a Self-Levelling head, a Fixed Head or the NEW Timber Decking Self Levelling Head.

Product Images
Key Points


  • A rainwater channel system in three sizes consisting of slotted sides with either grill or grate slotted grating.
  • Rainwater runoff is collated at hard surface level whilst percolation is relived at membrane level
  • Modulock slot sided channels can be used on podium decks, terraces and balcony areas in conjunction with Harmer Rainwater Outlets and Modulock Pedestal Support systems
  • Can be laid directly on the structural deck or fitted with height adjustable feet
  • A drainage system that intercepts rainwater and improves safety at point of access
  • Compatible with inverted roof, warm roof, green roof and podium deck construction
  • Threshold drainage with the level access requirements of part M
  • Pedestrian Load rated class K3
  • Channel lengths in a choice of three depths: 30mm, 40mm or 50mm
  • Modulock Channels form part of the overall drainage plan for most types of flat roof or deck construction.
  • Height adjustable feet elevate and correct cross falls and any irregularities in the supporting surface.
  • Buildings are protected from weathering at the venerable point where hard surface meets structure.
  • Channels and gratings are available in Grade 304 stainless steel or galvanised mild steel
  • Available with either a grill or slot grate finish
Installation & Fixing


  • Straight line end to end installation with simple location clips ensures the system is fully stable
  • Factory manufactured or site formed irregular angles accommodate change in direction
  • Modulock channels can be supported directly on the structural deck or supported on height adjusters for raised paving, varying from 50mm to 150mm
Overview and Installation
Timber Decking Supports