When it comes to roof ventilation there are as many types of roof ventilators as there are cultures.
All roof ventilators are developed to work in one climatic region, or another, and a great many are designed on appearance and cost, as opposed to performance.
Nowadays they are considered a necessary evil, a product that has become a necessity in principle, a have to have, in order to comply, with the building regulations of the day.
Ridge vents are one such product, an item seen to satisfy the building code which is ironic as the building code is assembled by those who know little or nothing about roof ventilation and then are blindly followed by council authorities who know even less.
A ridge vent provides you with an opening in the roof. Nothing more, nothing less. It will relieve pressure but it’s responsiveness will be dependent on the resistance within the design.
It’s function is presumed to be sufficient to the use of the building but always falls short to expectations. Why?…because it’s a product manufactured to a price in both construction and ease of installation.
Just as there are cars and there are cars….the same applies to all products bearing the same descriptive title….roof ventilators are no different
Given the ratio of cost to performance is so disproportionate one wonders as to why one is chosen other than to have something with a seemingly diminished presence as regard to aesthetics. In order for a ridge vent on a residential dwelling to be efficient the opening needs to be such that the free air flow has to overcome the resistance within the design.
Then when it’s discovered that there’s a short fall in performance the developer / builder / owner seeks alternative products to supplement that which is lacking. No thought is given to the fact that you cannot successfully merge the dynamics of one type of roof ventilation with another, and so the blind just continue to follow the blind and hope they find themselves on a far away beach when all comes to light.
Everyone’s an expert until it comes to taking responsibility then only the trail seen is that of the ‘roadrunner’ in the direction of the setting sun.
Added to this, the ability to close off a ridge vent so as to use the roof as a heat exchange during winter is nigh on impossible and at great expense.
The ridge vent is not suited to houses in Australian conditions and is only chosen when a diminished visual presence is sought at the expense of performance.