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Gas Barrier Membrane Cavity Tray Systems and Preformed Accessories

Gas barrier membrane cavity tray systems and preformed accessories to form a continuous protection system around the whole building perimeter.

Works in conjunction with radon, methane, CO2 and hydrocarbon gas barrier systems to contain rising gases across the footprint of the building.

Solutions include:

  • Horizontal cavity wall perimeter trays incuding corner units (PCT Range)
  • Horizontal slab perimeter Cavity Trays including corner units (SPT Range)
  • Stopends and change of level units
  • Radon Sumps (RSUMP01)
  • Top Hat Pipe Collars
  • NEW Flexible Top Hat
  • Column Cloaks
  • Televent gas sleeve tray (TST01)
  • Threshold internal protection Cavity Trays (TPT01)
  • Gastite sealing tape
  • Girth tape

For more information call 01405 765567 Free next day delivery *

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Features & Benefits

  • Forms a continuous protection system around the whole building perimeter
  • Preformed mouldings eliminate the need for site fabrication to prevent errors through poor workmanship
  • Easy to handle, flexible, tough, durable and puncture resistant
  • Can be used for multi-storey or high-loading applications – will not extrude under high loads up to the point of compression failure of wall
  • Wide range of standard components with special tailor made accessories also available
  • Fully itemised scheduling service


  • When gas protection is required across the footprint of the building
  • Following a risk assessment which resulted in a requirement for good gas protection against:
       -  Radon, CO2, Methane and Hydrocarbon
  • In areas outlined in BRE document ‘Radon’ guidance on protective measures in new dwellings
  • Crossing cavity wall constructions to maintain gas barrier integrity
  • Forming internal perimeter trays to allow membranes continuity
  • Service pipe protrusions

Technical Information

Horizontal cavity wall perimeter cavity trays - PCT Range

Supplied in 2.5 metre lengths and manufactured from heavy duty 2mm polypropylene.

They should be installed continuously around the external perimeter of a building to allow the membrane to be laid at a later stage and so prevent damage as building work proceeds.

Horizontal slab perimeter cavity trays - SPT Range

Supplied in 2.5 metre lengths and manufactured from heavy duty 2mm polypropylene.

They should be installed continuously around the internal slab pour area allowing the membrane to be laid at a later stage and so prevent damage as building work proceeds.

Stopends and change of level units

Available in the PCT range and manufactured from heavy duty 2mm PP.

Suitable if breaks appear in the natural run of the cavity tray system, and available in cavity size and rise options with 75, 150 and 225mm steps.

Radon sumps (RSUMP01)

Prefabricated sumps are required when a sub floor depressurisation is required under full radon protection.

The sump is installed beneath the floor slab in non-suspended floor applications and vented to atmosphere via a connecting 110mm drainage pipe to an external source and capped off with proprietary products ie, air bricks and telescopic under floor vents or roof vents.

Top hat pipe collars (TH055, TH082, TH110, TH135, TH160)

Top hat pipe collars are available in sizes from 55mm to 160mm.

A standard range of preformed pipe sleeves that are designed to have sealing tape applied to the unit base to offer a unit for sealing to a gas barrier and at the intersection of pipe projections.

Common applications are for soil/service pipes passing vertically via a gas barrier or membrane to maintain a continuous seal. Top hats are suitable for installation at ceiling level for pipe protrusions to assist in reducing air leakage.

All sealing tapes (GTAPE03) and fixing bands (JCLIP6 or 7) are supplied separate to top hat units

  • Jubilee clips size 6 (110mm – 140mm)
  • Jubilee clips size 7 (135mm – 160mm).

Flexible Top Hat (77110)

The Flexible Top Hat is available in size 110mm.

The NEW flexible top hat which has been designed to be flexible enough to fit around difficult applications and is perfect for use in tight situations where a pipe is located close to a wall.

All sealing tapes (GTAPE03) and fixing bands (JCLIP6 or 7) are supplied separate to top hat units

Televent gas sleeve tray (TST01)

For use when telescopic under floor vents need to pass through a perimeter cavity and still maintain gas tight integrity.

Threshold internal protection tray (TPT01)

Designed for detailing rebated areas inside door threshold to maintain water and gas tight integrity without having to trim membrane to fit. Due to possible variations in size, threshold dimensions will be required.

Column cloaks (made to order)

Non-standard applications can require gas and water integrity around columns and stanchions.

Timloc will design and produce rigid preformed units that are user friendly simply contact our technical department for further assistance.

Gastite sealing tape (GTAPE03)

A 2mm x 50mm wide double sided modified polymer strip, protected on both sides with a silicone release paper.

The principle is to apply between parts of the system in continuous joint lengths to achieve a gas tight seal. Also available in 100mm width rolls (GTAPE01).

Girth tape (GTAPE02)

A single sided 75mm wide tape with an aggressive adhesive to one side, used to cap overlaps that have been sealed with gastite tape to prevent uplift of joints when concrete slab or screed is poured.

How to Order

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

Our Technical Team will be pleased to advise the most suitable products for your project and will prepare a fully itemised schedule of quantities if required.

Please contact our Techncial Team with your project details or upload the full working drawings and specifications using our Upload Your Drawing facility at the top of the screen.

Installation Advice

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

  • As with the DPC, accessories should always be bedded onto fresh mortar, never dry bedded
  • The masonry laid over the DPC should also be bedded onto fresh mortar so that the DPC is approximately half way through the thickness of the mortar joint
  • DPC must be lapped onto the accessory by a minimum of 100mm
  • All lapped joints must be fully sealed with jointing tape. It is essential that the joining surfaces are clean and dry or the jointing tape will not seal correctly
  • Please don’t hesitate to contact the Timloc Technical Team if there is any doubt regarding installation

Quality, Regulations and Standards

  • Manufactured to BS EN ISO 9001 and BS EN ISO 14001
  • Satisfies all NHBC requirements
  • Meets BRE requirements
  • Complies with Building Regulation Approved Documents C1 and C2
  • Meets all relevant British Standards

Materials and Colour

  • Formed in 2mm medium density polyethylene and/or polypropylene
  • Available in black only
  • nbs plus
  • riba

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