Gas Barrier & Damp-Proof Accessories

Range of gas barrier membrane cavity tray systems and preformed accessories to form a continuous protection system around the whole building perimeter. Compliant with Building Regulation Approved Documents C1 and C2.

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

View the Products in the Range tab below for further information. Solutions include:

  • Preformed cavity tray system
  • PCT Range – Horizontal cavity wall perimeter trays
  • Corners – PCT and SPT ranges
  • Stopends and change of level units
  • Radon Sumps
  • 1201 Telescopic Underfloor Vent Top Hat
  • Threshold internal protection tray – Various profiles
  • Column cloaks (made to order)


  • In areas outlined in BRE document ‘Radon’ guidance on protective measures in new dwellings.
  • When gas protection is required across the footprint of the building.
  • Crossing cavity wall constructions to maintain gas barrier integrity.
  • Forming internal perimeter trays to allow membranes continuity.
  • Following a risk assessment where the requirement is for a good gas protection measure against Radon, Co2, Methane and Hydrocarbon.
  • To be designed and installed in a continuous system around the whole building perimeter.

Product Information

Gas barrier and damp proof membrane cavity tray systems and accessories

DescriptionProduct Code
Radon sump 350 x 350 mmRSUMP01
Threshold internal protection tray 930 mmTPT01
Televent gas sleeve tray (cavity tray profile reg.)TST01
Gastite sealing tape 10m x 100mmGTAPE01
Girth tape 50m x 72mmGTAPE02

Product codes to suit cavity widths of:50mm75mm100mm
PCT150 Perimeter cavity tray 150mm rise51015102†5103
PCT150 External 90° corner cavity tray511051125114
PCT150 Internal 90° corner cavity tray51115113†5115
PCT150 Cavity tray stopend RH5130†5132†5134
PCT150 Change of level 75mm step5131†5133†5135
PCT150 Change of level 150mm step9060†9063†9066
PCT150 Change of level 225mm step9061†9064†9067
PCT225 Perimeter cavity tray 225mm rise9062†9065†9068
PCT225 External 90° corner cavity tray5104†5105†5106
PCT225 Internal 90° corner cavity tray51165118†5120
PCT225 Cavity tray stopend RH51175119†5121
PCT225 Cavity tray stopend LH51365138†5140
PCT225 Change of level 75mm step51375139†5141
PCT225 Change of level 150mm step9070†9073†9076†
PCT225 Change of level 225mm step9071†90749077
† For internal use only9072†9075†9078

  • 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. It 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
  • 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
  • Formed in 2mm medium density polyethylene and/or polypropylene.
  • Available in black only.
  • Units will require tape and seal (tape sold separately). Use GTAPE01 to make the seal between joint surfaces. Use GTAPE02 to seal upper surface to minimise lap lifting if used in concrete floors.

Preformed cavity tray system
Works by reducing on site exposure to the membrane through the use of independent performed and rigid cavity trays installed to the perimeter of the building, in both the cavity wall with our PCT range and installed at the slab edging with our SPT range.

PCT Range – Horizontal cavity wall perimeter trays
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 works proceeds.

Corners – PCT and SPT ranges
Available in both SPT and PCT ranges and manufactured from heavy duty 2mm polyethylene. The standard corners are 90° but a wide range of options are available and selection is by cavity size, wall construction and damp proof course or slab rise required.

Stopends & 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 i.e. air bricks & telescopic under floor vents or roof vents.

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.

  • Timloc can prepare a comprehensive schedule and quotation service. Forward full working drawings and specifications to our technical department.
  • Orders can be established from written quotations by stipulating number issued.

F30 Accessories/sundry items for brick/block/stone walling.


  • Manufacturer: Timloc Building Products, Timloc House, Ozone Park, Howden, East Yorkshire, DN14 7SD. T: 01405 765567 W: www.timloc.
  • Reference: e.g. Top hat pipe collar
  • Size: e.g. 110mm
  • Product code: e.g. TH110
  • Use: For use in all types of floor construction to protect buildings against gas penetration from the ground. To cover the full footprint of the building and to incorporate proprietary accessories for pipe, vent protrusions.

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