Cavity Trays discusses water evacuation in walls

Visually, external discolouration, salt emission and eventual permanent staining will blemish the appearance of the structure.

Internally, any sufficient water trapped or reservoirs within the cavity, will permeate inwardly.

If water is prevented from evacuating the structure, it will eventually find alternative routes.

Structurally, the masonry and mortar joints will suffer premature deterioration, and spalling will occur when trapped water freezes and expands, eventually resulting in masonry cracking, loosening and delaminating.

Cavity Trays also highlights that the need to drain cavity walls is not limited to window and door heads.

Changes of level, roofing intersections and ringbeams are further examples of construction that is reliant on water being adequately evacuated.

Caviweeps ensure water is not trapped within the structure but can exit speedily.

Cavity Trays manufactures five versions of caviweep in different colours including caviweeps with insect screening, discreet external appearance, and integral wind baffles, to suit all styles of mortar and masonry.

There are versions to suit masonry with drafted margins or restricted bed and perp joints as encountered with ashlar walling.

Once an external masonry leaf has become saturated and cannot absorb further rain, it acts as a conveyance sponge allowing up to 2.25 litres of water per hour can pass through every m2 of it during ongoing rain.

Some styles of masonry are more resilient to ingress, so wall design must always anticipate the most extreme exposure possibilities, so evacuation provision is always adequate.

Cavity Trays will be pleased to assist the optimisation of water evacuation provision upon request.

Where caviweeps are used with cavitrays manufactured by Cavity Trays, the combination benefits a performance warranty for the advantage of Architect Builder and Client.

Cavity Trays is the only cavity tray manufacturer awarded European Technical Approval.