Ventilators - Air bricks and Vents
Introduction
It is sometimes not possible to use conventional air bricks and vents, particularly
those made of plastic, due to their impact on the historic character of a building,
particularly in stone walls. As an alternative high quality cast iron, aluminium or
ceramic air bricks and vents may be used or specially designed drilled or louvred
stone solutions - possible designs are shown below.
The choice of air brick or vent should be guided by the historic character of the
building.
Drilled Ventilator
The stone chosen must be at least 225 x 225mm and free of cracks and
imperfections. Before insertion into the building, thirty six 12.5mm diameter holes
should be drilled in the stone at regular intervals.
Cotswold District Council
www.cotswold.gov.uk
2011
Louvred Ventilator
A greater free flow of air can be achieved with a louvred ventilator, compared with a
drilled ventilator. Conventional stone tiles can be used, trimmed to fit a 225 x 225
mm opening. The tiles should be bedded on mortar, leaving a 10mm air gap
between each layer.
General points on stone ventilator installation
To prevent infestation by insects, a fly proof grill must be secured to the rear of the
block.
Any ducting must be sheathed through the inner leaf and cavity by a rectangular
slate, plastic or terracotta sleeve. Ducting should be sealed with mortar or similar
material to prevent leakage back into the property.
Ducts must be laid with a slight fall reducing the risk of damp penetration.
For trickle vents a hit or miss grill should be fitted on the room side.
It is important to ensure that any vents or air bricks are compliant with the appropriate
Building Regulations - for further information please contact
BuildingControl@cotswold.gov.uk.
For any general planning or historic building conservation queries, please contact
planning@cotswold.gov.uk
Cotswold District Council
www.cotswold.gov.uk
2011