Why would I need a Chimney Cowl?

A chimney cowl is a device that is fitted to the top of a chimney stack, usually made of metal, plastic, terracotta, or mesh. It has several functions which range from safety to improving performance of the chimney and reducing maintenance.

The main reasons why you would want a chimney cowl fitted are:

1. Stop rain water and snow from getting in – Rain and snow can cause issues for your chimney flue. A little rain may not be a problem, but over time it can accumulate moisture (particularly in months where the fireplace is not in use) which will damage your chimney and be costly to repair. The same is true of snow, though if you are lighting the fire often during snowy seasons, this will help evaporate any moisture. A cowl is designed to prevent this from happening.
2. Prevent birds & animals entering – A chimney is a perfect nesting location for birds, and that causes many issues. First, it will prevent the proper operation of the chimney by stopping air drawing through. Then there are the issues from bird droppings and debris coming down your flue pipe, as well as noise and even a risk of chimney fires. Worse still, it’s not unusual for animals to fall down the chimney. This can result in them either falling into your fireplace and getting into your home, or causing a dangerous obstruction inside the chimney. In all cases, animals are the scourge of the fireplace! By blocking the chimney using a bird guard device, you keep things safe for both yourself and the local wildlife.
3. Eliminate downdraught – Downdraught occurs when the outside air pressure forces smoke back down the chimney, entering your home which of course you don’t want. Anti down draught chimney cowls prevent this happening by stabilising the air flow. Downdraught is not just annoying, it can be extremely dangerous to you and your family. As well as creating unpleasant odours in your home, the smoke can contain high volumes of Carbon Monoxide which is toxic and hazardous to health. If downdraught is a problem, it’s important that you take steps to install a suitable anti-downdraught chimney cowl as soon as possible.
4. Increase chimney draw – One essential aim is to improve the function of chimney flue in drawing air up from the fire or wood burner below to enable smoke to quickly escape. For flue systems with a particularly weak draw, a rotating chimney cowl is recommended. However, such cowls should not be used in cases where no draw problem exists, as they can be counterproductive and cause your fire or stove to overfire.

What is the best chimney cowl?

The best type of cowl for your home will depend on several factors, from the type of fireplace (open fire, wood burner, gas fire etc) through to the location and age of the property. We recommend you get professional advice from a chimney specialist or give our friendly sales team a call on 0344 800 6586 for help and advice.