A cavity tray is an internal moisture or water barrier featuring a series of trays designed to stop rainwater from falling into the cavity wall and causing damp above any windows and doors included in the design. Any damp is usually the result of heavy rainfall soaking the external brickwork and seeping into the cavity between the inner and outer walls. This is something that needs to be seriously thought about when a current external wall of a house is adapted into a rear internal wall due to the installation of a conservatory, orangery or solid roof extension.
It’s difficult to give a definitive “yes” or “no” answer until we have assessed your property to see whether we think there is a possibility of heavy rain causing ‘wet wall’ issues or damp.
A lot of contemporary bricks absorb water easily and on new-build properties you will spot small plastic vents sat above ground level windows and doors. They’re commonly termed ‘weepers’ and they’re job is it enable rainfall to flow out of them when they meet the lintel supporting the brickwork above the windows and doors. This doesn’t mean though that a cavity tray won’t be necessary.
We also need to inspect the compass orientation and height elevation of the appropriate side of the property as those facing south or south west are more susceptible to rainfall exposure. Another determining factor will be the volume of brickwork utilised above the ground floor windows and doors as this increases the chance of a high level of absorption over exposed areas.
As we’re constantly reminded, we live in one of the world’s rainiest countries. It’s not unusual for some parts of the region to experience a month’s worth of rain in a single day and it’s won’t get dryer in the long-term that’s for sure.
Increased rainfall over the past few years has necessitated the installation of a cavity tray retrospectively in many old extensions that previously went without one.
Erring on the side of caution is ultimately your best bet as a cavity tray will future-proof your conservatory or orangery against potential damp, so ask us to include it in the final costing up of your chosen design.
© 2018 Clearview Home Improvements Ltd.
Authorised and regulated by the Financial Conduct Authority.