Where a pitched roof conservatory or extension attaches to an existing cavity wall, flashing the intersection only will not prevent dampness permeating downwardly within that skin. Insertion of Type X Cavitrays above the new roofline can arrest such dampness and be used to satisfy Building Regulations.
Insertion entails cutting out masonry on a progressive basis, a distance above the roof of the new structure. Once a few bricks (or equivalent) have been removed, the hinged upstand of the Type X Cavitray is turned down until it is horizontal. This permits the tray to be inserted into the opening and bedded on mortar. As the tray enters the opening the hinged cavity upstand is allowed to flex upwardly. So doing enables it to service the cavity width as encountered. This is repeated in subsequent courses until the top is reached where the last tray to be inserted is normally a ridge tray.
For insertion into existing cavity walls, to introduce a functional DPC and flashing where an existing has failed, has been omitted, or is required because a new pitched roof is to abut. (eg. extension or conservatory roof).
- Solid DPC Polypropylene.
- Lead flashing BS EN 12588.
- Specify pitch, lead length, handing and whether external skin is brickwork. Water drip bars eliminate underbase track-back.
- Correct mortar bedding depth is also established as bar dimensions harmonise with front of tray section to aid stability and mortar integrity.
- Integral cavitray sealing flap links with upper tray.
- Feature on the tray end upstand arrests horizontal tracking at this vulnerable point.
- Adjusts for cavities from 50mm up to 140mm.