The current varieties of chimney cap designs are preferably constructed from copper or sheet steel. According to modern chimney construction procedure, the chimney cap should fulfil the purpose of preventing the entry of rain and/or snow into the chimney, thereby averting a loss of moisture through the clean-out door or build-up of dampness within the chimney or flue itself.
Without a doubt, the mounting of chimney caps has become somewhat of a fashion. They are not a necessary requirement and it has also been proven that they have a negative effect on the chimney draft and consequently on the burning efficiency of the fire.
Why can conventional chimney caps have a negative influence?
Warm, steadily cooling air rises in the flue and should exit the chimney as soon as possible. With the introduction of a covering on the top end of the chimney an obstacle is created in the form of a warm air bubble. It is common knowledge that the colder the outside temperature, the better smoke and fumes can exit the chimney, but in the case of a capped chimney it can also lead to a congestion of fumes which then start to condense on the roof or chimney crown. The results are clearly visible in the black deposits on the roof and chimney and also in the stains left behind on the house itself when the deposits are washed away by rain.
It’s imaginable how the chimney looks inside. Expensive secondary damages are certain.
It should also be mentioned that chimney caps often present an obstacle for chimney professionals in completing their work, frequently preventing a proper cleaning.
We, from ROTOVENT® Systems, advise you to think twice about either mounting a conventional chimney cap or even better a ROTOVENT®, which protects the chimney not only just against rain and snow without creating an obstacle in the form of a warm air bubble but moreover has lots of necessary and important qualities.
Your decision should be made easily, particularly when you consider the fact that a ROTOVENT® may be much cheaper than a chimney cap made out of high-grade steel.
We really do not want to talk something down, but do not want to deprive something either. Go and ask an expert of your own confidence and reassurance.