Inter-loc Horizontal Cavity Trays – Lead Attached

Preformed leaded horizontal cavity tray system for new build and existing walls.

Featuring integral interlocking lapped joints to securely join cavity tray lengths together and create a watertight run which eliminates the requirement of additional tray jointing adhesives (taping etc.) on site.


  • At the abutment of a flat roof with a cavity wall
  • At the abutment of a lean-to or mono pitch roof with a cavity wall
  • On external walls – not exceeding 102.5mm in thickness – built from standard brickwork, blockwork or stone
  • Clear cavity widths of between 50mm-125mm

Product Information

New build applications with lead attached
150mm drop lead Inter-loc system horizontal leaded cavity trays

DescriptionEffective LengthProduct Code
Inter-loc horizontal tray 4 brickIL4L150
Inter-loc horizontal tray2 brickIL2L150
External 90° corner1 brickEXT90L150
Internal 90° corner1 brickINT90L150
External 135° corner330mmEXT135L150
Internal 135° corner150mmINT135L150

New build applications with lead attached
300mm drop lead Inter-loc system horizontal leaded cavity trays

DescriptionEffective LengthProduct Code
Inter-loc horizontal tray4 brickIL4L300
Inter-loc horizontal tray2 brickIL2L300
External 90° corner1 brickEXT90L300
Internal 90° corner1 brickINT90L300
External 135° corner330mmEXT135L300
Internal 135° corner150mmINT135L500

  • Supplied with factory fitted lead flashing ready cut to suit the pitch of the roof and type of roof covering.
  • Fits all cavity sizes up to 125mm.
  • Suitable for brick, block and stone wall construction (cutting of masonry may be required)
    – 150mm high back upstand exceeds minimum requirements.
  • Angled section between cavity.
  • Interlocking mechanism for joining tray lengths to eliminate tray jointing.
    Built to brick bonding lengths for ease of use.
  • Angled section between cavity tray base and rear upstand automatically sheds water to the outer leaf.
  • Built independent to the inner leaf will enable inner and outer leaves to be built independently, if required.
  • Available in two lengths: 4 brick for general use and 2 brick for reducing waste when making up a run of cavity tray to the required length.
  • Satisfies all NHBC requirements
  • Manufactured to BS EN ISO 9001 and BS EN ISO 14001
  • Complies with all relevant Building Regulations
  • Meets all relevant British Standards
  • Flashings are Code Blue milled lead as standard as defined by BS EN 12588 : 1999 (formally known as Code 4). Horizontal Inter-loc units are injection moulded in 2mm polypropylene.
  • Accessories are vacuum formed in 2mm medium density polyethylene.
  • Available in black only.

Horizontal Inter-loc cavity trays
The main cavity tray component sections join together by means of a lapped interlocking join, to form the main cavity tray run. Water is gathered by the cavity tray and is discharged from the wall through a series of weep holes – one weep hole per Inter-loc tray is required.

Corner units
Allows the integrity of the main cavity tray run to be maintained when it is necessary to turn a corner on a building. Available in either external or internal format.

Fitted at the start and finish of the cavity tray run to seal off the open ends and prevent water running back into the cavity.

  • Each component is available to suit clear cavity widths of either 50-125mm.
  • Weep holes must be provided in every cavity tray to comply with Building Regulation requirements. These can be formed by installing a purpose made Timloc plastic wall weep unit.
  • Each Inter-loc cavity tray fits to the next by means of a lapped interlocking join, as work proceeds while working from right to left.
  • With rigid pre-formed cavity trays such as the Inter-loc system it is not necessary for the cavity tray to span all the way across the cavity. As long as the cavity tray stands back from the rear face of the external wall and projects back into the cavity far enough to intercept drips falling from the wall ties, then it will perform effectively.
  • To calculate quantities, divide the overall length of the cavity tray run by .225 (representing one brick and joint) to give number of bricks required then divide by 2 for IL2 or 4 for IL4 to give tray quantity. Always round up to the next tray because excess length can be cut away.
  • If the cavity tray is required to turn a corner, ensure that the correct corner units are ordered.
  • Please use stopends if the cavity tray has to be cut down to suit the project.
  • Stopends will not be required when the cavity tray run is built within the body of the building i.e. bay windows. For this application, the integrated stopend can be built into the next available joint projecting past the abutting roof.

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