GB2280948A - Chimney flue ventilation cap - Google Patents

Abstract

A chimney flue ventilation cap has a cap 1 to cover and overlap the top of a chimney pot 4 and incorporates a grill 3 below the cap which will allow ventilation of the chimney flue whilst preventing ingress of rain, snow, birds, leaves or other airborne debris into the flue. The cap also incorporates downward projecting legs 2 which when fitted into the pot, bear outwards to grip the pot and retain the cap and grill in position. <IMAGE>

Description

CHIMNEY FLUE VENTILATION CAP This invention relates to a chimney flue ventilation cap.

When the chimney flue of a domestic open fire is disused, defects can arise in the structure of the building if (a) the top of the flue is not sealed off or 'capped' to prevent ingress of rain, snow, nesting birds and airborne debris and (b) the flue is not thereafter maintained in an adequately ventilated condition to ensure evaporation of any condensation or other moisture within the flue. The provision of ventilation to the flue is important also to ensure the removal from the flue of any noxious gases which might leak into the flue from any adjoining flue.

Sealing of the flue is traditionally achieved by (i) removing the chimney pot and capping off the top of the flue with a concrete, slate or stone capping and (ii) blocking up the flue opening at room level. Ventilation of the flue is traditionally achieved by installing a ventilator within the closure of the flue at room level and by incorporating (by various methods) a means of ventilation to the flue either within the capping at the top of the flue or within the walls of the chimney stack. The work required at stack level is labour intensive, often also requiring erection of expensive scaffolding. If the flue needs to be restored to use at any time, further substantial work and expense is required to achieve this.

According to the present invention there is provided a chimney flue ventilation cap which fits into the top of the chimney pot and incorporates a cap to cover the top of the chimney pot together with a ventilation grill which allows movement of air into or out of the flue whilst preventing ingress of birds and debris.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows a cross sectional drawing of the ventilation cap as fitted in the top of a chimney pot.

Figure 2 shows, to a smaller scale, the ventilation grill which is fitted into the underside of the cap.

Referring to the drawing, the flue ventilation cap is circular in plan. It comprises a cap 1 with three downward protruding legs 2 and a circular grill 3. The top of the cap is conical in section and is of a diameter larger than the top of the chimney pot 4. Of similar diameter to the cap, the grill 3 is fitted into the underside of the cap 1. The cap 1 and grill 3 are then held in place on the top of the chimney pot by insertion into the pot of the protruding legs, each of which bears outwards to grip the inside face of the pot. Both the cap 1 and the grill 3 are wider in section than the top of the chimney pot to which they are to be fitted, to allow ventilation to pass through the grill where it overhangs the sides of the chimney pot. The legs 2 are slanted outwards so that when fitted into the pot they exert lateral pressure against the inside of the pot to grip the inner surface.

Claims (4)

1. A chimney flue ventilation cap which fits into the top of the chimney pot and incorporates a cap to cover the top of the chimney pot together with a ventilation grill which allows movement of air through the flue whilst preventing ingress of birds and debris.

2. A chimney flue ventilation cap as claimed in Claim 1 wherein the cap and grill are of rectangular shape.

3. A chimney flue ventilation cap as claimed in Claim 1 wherein additional protruding legs are incorporated.

4. A chimney flue ventilation cap substantially as described herein with reference to Figures 1-2 of the accompanying drawing.