Ventilation

Part F of the current regulations prescribes requirements both to meet the needs of the occupants of the property and also to prevent excessive condensation in roof spaces and also rooms within the dwelling. A key aim in relation to fitting ventilation to a retrofit house or a new build is to minimise the risk of condensation, mould growth or any internal air quality problems.

So what does this mean to the homeowner?
When completing Insulation on a house, we as installers are obliged to assess the property for ventilation requirements. There are two types of ventilation required for this.

1. Attic Ventilation
2. Wall Ventilation

ATTIC VENTILATION

Ideal circumstances a 10mm strip on the soffit cross ventilating front to back means no ventilation is required. Some dwellings have some existing ventilation in the soffits already, which will be in the form of strips in the underside of soffit, which may need a small amount more to bring it up to the current standards. These can be installed as circular 70mm diameter soffit vents which are cored into the underside of soffit to allow air flow into the attic. If this isn’t suitable, a roof vent is installed. This is basically the installation of a vented roof tile in replacement for an existing slate or tile.

WALL VENTILATION

When insulating walls, it is imperative to ensure every habitable room has an existing vent. This means all bedrooms, living rooms, kitchens and utility rooms must have a vent installed in the wall or in the window. It is possible that this can come in the form of a window trickle vent or in a wall. If there are no vents in these rooms, we can install wall vents or window vents to ensure that the house is compliant with Part F of the current building regulations. All vents will be closable, apart from rooms that have an open fire place or stove. The reason these are permanent is because the solid fuel burners will create carbon monoxide which can potentially be harmful to the homeowner. We are obliged to leave a permanently opened vent in this room to allow the potentially harmful fumes to escape.