Basic primary attic ventilation is used to maintain the unused portion of our house.
Some of us think exactly the opposite and close all ports attic vents, sometimes to protect the roof decking (in the unconditioned attic), assuming that such actions will lower utility bills. Unfortunately, in doing so, they create an ideal growing environment attic mold (humid and warmer than the exterior).
You can partially determine how good your attic ventilation is by inspecting the roof surface during winter (from the ground of course!). After some snow accumulates on the surface of pitched roofs, observe it for a few days. If your roof is still covered in snow, there is a good chance that your attic is ventilated. To get more information, you can get through https://www.nuneatonrooftruss.co.uk/
According to a source of heat in the attic, at every part of the roof surface snow began to disappear. With temperatures above freezing, the investigation may be inaccurate, and you have to open the loft hatch.
Ideal roof/attic ventilation will consist of a combination of vents located at:
The top of the attic (ridge vents, turbine, or dome-shaped box static ventilation, ventilation electric motor powered).
Ventilation installed along the bottom of the roof overhang, or soffit vents, ventilation hips, and / or gable vents.