Skip to main content

Cavity Trays for Arched and Circular Doors and Windows

Tailor design and made cavity tray systems for all types of external arched and circular door and window openings.

Any size, type or radius of curve can be fabricated to suit all clear cavity widths and forms of masonry.

Single piece seamless mouldings eradicates on-site fabrication, which can be a time consuming and complex process which is often prone to errors and DPC failure through poor workmanship.

Easy to handle, yet extremely durable; preformed cavity tray systems are an effective method of DPC and present many benefits including consistent and steadfast protection, a swift and straightforward installation and reduced cold bridging opportunities and site material waste.

Cavity Trays for Arched and Circular Doors and Windows are made to order – please contact the Timloc Technical team on 01405 765 567 or with your project requirements

For more information call 01405 765567 Free next day delivery *

Get your free Cavity Tray project take-off

Send us your project details...

View product range & add to quote

Features & Benefits

  • Any size, type or radius of curve can be produced
  • Can be supplied as single piece or in multiple sections
  • Designed and manufactured to integrate with the project’s specific requirements
  • Puncture resistant material
  • Strong and reliable DPC method
  • Can be time, labour and material saving
  • Eliminates on-site fabrication and DPC system failure through poor workmanship
  • Does not extrude under high loads
  • Easy to handle
  • Reduces cold bridging
  • Generally doesn’t require cutting into insulation material
  • Allows inner and outer wall leafs to be built independently if required


Around the opening of external:

  • arched/curved door and window openings
  • circular (bullseye) windows.

On external walls with any clear cavity width and built from:

  • brick
  • blockwork
  • stonework
  • timber frame constructions.

Technical Information

We produce dimensional drawings for all bespoke cavity tray systems, for submission to the client   for their approval before manufacture.

Cavity tray systems work in association with weep holes:

  • trays collect and keep water within the cavity
  • weep holes release the water through the external wall.

Weep holes must be included as part of all cavity tray and DPC installations to adhere to Building Regulation requirements. 

We recommend purpose made weep holes/weep vent units, such as Timloc’s:

  • wall weep vents (1143 range)
  • concealed wall weeps (TW1 range).

Required Project Information

Arched and circular cavity tray systems are designed and made to order, therefore please supply the full construction details, including:

  • door/window opening size/s
  • wall construction and insulation material details
  • radius of curvature
  • position of spring line
  • lintel manufacturer drawings
  • stonework manufacturer drawings.

Ideally these will include fully dimensional project drawings.

We strongly recommend that customers take advantage of our free of charge cavity tray specification and project take off service.

Our Technical Services Team will gladly advise the most suitable project solution and will prepare a fully itemised schedule of quantities if required.

Installation Advice

On-site installation and best practice guidance is all part of our service, please don’t hesitate to contact us to arrange a site visit.

If there is any doubt regarding the correct method of installation please don’t hesitate to contact the Timloc Technical Team.

  • Generally arched and circular cavity tray systems are positioned so that the upstand fits between the door/window frame and external masonry.
  • The upstand can be trimmed back after installation to be flush with frame and sealed with exterior mastic in the normal way.
  • Weep holes must be provided at the base of the arched/circular cavity tray – at both sides of the opening.
  • We recommend that weep holes are formed using Timloc’s wall weep vents (1143 range) or concealed tunnel weeps (TW1 range).
  • Circular and arched cavity tray systems supplied in 2 or more sections are joined by means of a lapped joint that is sealed with butyl mastic tape.
  • All jointing surfaces must be clean and dry.
  • Circular and arched cavity tray systems are usually supplied with an integral flap which builds in to the inner leaf for secure positioning.
  • If building in is not possible, such as timber frame construction projects, then the cavity tray flap should be mechanically fixed to the inner leaf.
  • DPC should always be installed to the codes of practice relevant to the project.
  • High quality workmanship, cleanliness and attention to detail are essential with all DPC and cavity tray installations.

Quality, Regulations and Standards

  • Satisfies all NHBC requirements
  • Complies with all relevant Building Regulations and Standards
  • Manufactured to BS EN ISO 9001 quality management system
  • Manufactured to BS EN ISO 14001 environmental management system

Material and Colour Choice

  • Most made to measure cavity tray systems are vacuum formed in 2mm thick medium density polyethylene
  • Available in black only
  • nbs plus
  • riba

Web Design by Bluestorm