Can I have too many roof vents? The answer is you can have too many roof vents, not enough or even two different types that do not work well together.
In saying this the objective of effective roofspace ventilation is to have a system of balanced roof vents of the same enclosed space (volume) for want of a better word – a balanced system of two ventilators of the same volume and a pair of vents for each section of roof will achieve excellent results for the circulation of ambient air temperature throughout the previously unventilated or ineffectively ventilated roofspace.
The previous statements refer to the best way of ventilated roofspaces.
The answer to the question can I have too many roof vents is obvious as many types of roof vents are not part of a balanced system – you can have a set of scales with 1 kilo of butter on one side and 2 kilos on the other side, the scales will always fall to the 2 kilo side this is a totally unbalanced system and will always fail to keep a balanced situation.
It is exactly the same for roof ventilation – you can have too many roof vents or not enough of two kinds that are not equal volume, this will always fail to keep a balance and effectively ventilate the roofspace.
In conclusion, yes, you can have too many roof vents.