Cavity Walls Cavitray Protected
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Incorporating a level of protection that works regardless of the site exposure categorisation makes sense.
Conventional roll DPC is commonly used to provide protection against wet ingress over window and door openings in cavity walls. The downside is roll DPC cut on site can end up being inconsistent in shape, inconsistent in length and there can be difficulty addressing all the NHBC / LABC recommendations. A solution is to use a preformed Cavitray.
When horizontal preformed Type C Cavitrays are used with lintels, one eliminates the variances that occur with a site-fabricated approach. Preformed Type C Cavitrays are ready-shaped to harmonize with the window head construction / lintel choice, so the build detail is always consistent and always correct. Type C Cavitrays are also self-supporting, which means they hold to profile and do not require building into the inner skin. So no seeking out a bedding joint at an appropriate height to hold up the protection, the Cavitray ensures full cavity width arrestment whilst both skins remain independent of each other so adverse thermal bridging does not arise.
Importantly, Type C Cavitrays have extended ends that project each side of the wall opening by 300mm. These extended ends serve two purposes: Firstly, they ensure adequate shelter of whatever reveal closing method is deployed and secondly, the 300mm projection guarantees a brick perp joint beyond the opening is always located to accommodate the stopends in the optimum position. So when lintels have only 150mm bearings (such as those within the 900 to 1600mm length range), the 300mm extension ensures the stopend can still be naturally accommodated without breaking bond – despite the first available perp being 75mm beyond the lintel end when standard 225mm bricks are used).
Finally, preformed Type C Cavitrays can be supplied with a drip lip moulded to the tray front in a position to coincide with the top of the window or door frame. Thus the recommendation within NHBC 6.1D6b to provide a lip at this point is fulfilled automatically.
Cavitray scheduling is straightforward – the Company does it for you. Trays are delivered packaged per plot, so stock and cost is controlled. Importantly, the house builder benefits a consistent build detail – every time.
Cavity Trays Ltd of Yeovil is the longest-established company in its specialised field and the only UK cavity tray company awarded European Technical Approval. Accompanying performance warranty for the benefit of Architect, Builder and Client.
Cavity Trays of Yeovil
