It is understandable that the look of cement rendering can be quite attractive when finished, as the wall appearennce seem quite clean. However in some cases when this is done it is easy to render over existing passive vents which will make the minimal sub floor ventilation non-existant. This can pose a problem in that, the sub floor area does not breathe which will pose problems associated with a lack of sub floor ventilation such as: high humidity levels which can pre-dispose the dwelling to a termite attack, raised internal humidity levels within the dwelling which can start the mould cycle to create poor air quality inside the home which will impact on the occupants. To curb this problem from happening it is our recommendation for the renderer to allow the vents to remain and if the air-flow is still inadequate then the vent or vents can be replaced by an Envirofan fan-forced system whether brick size or terra-cotta vent size (two bricks high x one brick wide).
Envirofan Sub-Floor Ventilation Solutions, Sydney – Reduce Mould & Prevent Termites
Protect your most valuable asset, your home, with an Envirofan sub-floor ventilation solution