Ventilation is necessary in every home. It is what keeps your attic from overheating and your roof from being damaged. It is the process of moving hot, stale air from the attic and re-circulating fresh air into it. This is usually done with a hi-volume steady air flow.
Because heat rises and inadvertently winds up in the attic of a home in the summertime, a lack of ventilation can not only damage the roof of a home, but can also be considered a potential fire hazard.