Z-Led Cavity Trays

In cavity walls, DPC and cavity tray design should be based on the assumption that rain will penetrate the outer leaf of brickwork or blockwork and run down the inside face. Anything that crosses or obstructs the cavity can form a bridge allowing water to cross and soak through the inner leaf, causing damp within the building. In the same way, abutments to the outside wall require protection from water penetration due to this wall becoming an inner wall below the abutment.

Building regulations provide that adequate measures be taken to prevent moisture being carried to an inner leaf or an outer leaf that becomes inner. The Richmond range of Cavity Trays provides an effective and economical means of dealing with this problem.

The Three Types and Where They Are Used:

The Catchment or Starter Tray
This tray is the first to be built into the outer leaf. It has upstands at both ends and a central discharge channel for any water that may run down from the trays at a higher level. The upstands ensure that water cannot penetrate the cavity and is safely diverted on to the roof covering.

The Intermediate Tray
This tray is handed, with an upstand at one end preventing water from penetrating the cavity. Each tray has a discharge channel to divert water safely on to the roof covering. Each tray must overhang the lower by at least 100mm.

The Apex Tray
This tray is identical in design to the Catchment Tray and is the last to be built into the outer leaf. Depending upon how the intermediate trays finish in relation to the brickwork, this tray may have to be adapted by removing one or both upstands. This will avoid cutting bricks which are visible on completion and allow water to discharge on either side.

Lead Flashings
Trays are available with either Short or Long Code 4 Lead Flashing. Short Flashings are generally used to dress over the upstands of soaker units whereas Long Flashings can dress over the adjacent profiled tiles.

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HT Trays are used:

1. At top edge abutments of lower level pitched roofs.
2. Where flat roofs abut the outer leaf of a cavity wall
3. At the base of masonry cavity walls where built off a concrete slab.
4. Over air bricks, ducting and other services which bridge the cavity.
5. Suitable for brickwork and blockwork.
6. Self-supporting design allows use with cavities from 50mm to 100mm, avoids the need to build inner and outer leaves together and to line up bed joints in brickwork and blockwork.
7. Interlocking design ensures overlap of at least 100mm as recommended by BS 8215: 1991.
8. Complies with BS 5628: Part 3: 1985.
9. Preformed from polypropylene with internal and external corners, step units and stop ends.
10. Also available with factory-fitted code 4 lead flashings for use at the abutment of a lean-to or flat roof with a wall; these remove the need to rake out joints and point in flashings, saving time, cost and additional trades.Comprehensive installation instructions provided.
11. HT Trays without flashing

Lengths:
HT3 675mm, 3 brick module
HT4 900mm, 4 brick module
HT5 1125mm, 5 brick module
Other lengths easily cut on site.
HT Trays with factory-fitted flashing Lengths as above.
To order, add /L for long flashing (roof pitches below 30°) or /S for short flashing (roof pitches of 30° and above, and flat roofs).

HTR Refurbishment Tray
For refurbishment work and repairs to failed cavity trays, or where an extension with a lean-to or flat roof is built against an existing cavity wall.

1. 2½ brick length for ease of installation.
2. Self-supporting design allows the trays to be used with cavities from 50mm to 100mm without the need to build-in to the inner leaf.
3. Complies with BS 5628: Part 3: 1985.
4. Stop ends prevent moisture entering the cavity at the end of a tray run in compliance with BS 5628: Part 3: 1985 and BS 8215: 1991.

HTR Trays with factory-fitted flashing
Factory-fitted code 4 lead flashings remove the need to rake out joints and subsequently point in flashings, saving time, cost and additional trades. To order, add /L for long flashing (roof pitches below 30°) or /S for short flashing (roof pitches of 30° and above, and flat roofs).

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CT Chimney Trays
Protect against water penetration at high or low level.

1. Comply with Building Regulations and NHBC Standards, which require the use of metal trays in chimneys
2. Preformed components help to achieve a high standard of appearance
3. Eliminate the need for labour in forming units on site.
4. One-piece welded designs for speed of installation.
5. Maintain protection whilst accommodating normal site inaccuracies.

AR Arch Tray
Provides full dpc protection to arches constructed with temporary formwork.

1. Enables traditional formwork construction methods.
2. Does not require tying in to inner leaf of masonry
3. Purpose-made to rise, radius and shape required.
4. Durable polypropylene.

BE Bullseye Window Tray
Preformed 360° tray providing full dpc protection around a circular or bullseye window

1. Purpose-made to window size.
2. Drains positively to the outside.
3. Two-piece design assists installation
4. Durable polypropylene.

ST Sill Trays
Used under sloping brick sills to provide an effective dpc and a guide for forming the sill. Suitable for use with a 50mm wall cavity.

1. Front lip provides accurate brick alignment during installation (remove after mortar has set).
2. Effective purpose-shaped dpc, allowing vertical dpcs to be weathered into the tray.

Lintel Trays
Used with steel lintels to comply with BS 5628: Part 3: 1985 and BS 8215: 1991 for cavity trays with stop ends over all openings. As steel lintels should last at least 60 years, LT Trays are a small price to pay for added protection.

1. Self-supporting design can be used with cavities from 50mm to 100mm without building-in to inner leaf.
2. Stop Ends can be positioned to fit brick perpends.
3. Non-Slip textured finish for improved mortar adhesion
4. Modular brick lengths up to 2250mm in 1, 2 or 3 brick course heights.
5. Suits most common types of steel lintel including Catnic, IG, BAT, Dorman Long, Birtley, Rom, Hilsmith and Asset Building Components.

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