Attic ventilation is necessary to allow air to flow through your attic so that the moisture that accumulates has somewhere to escape. If an attic does not have any or not enough ventilation mold and mildew can form, and the shingles on your roof will age prematurely. In fact most manufacturer warranties will be voided if you do not have adequate ventilation.
Attic ventilation comprises of two key components: an intake and an exhaust.
The intake is often the most overlooked and on most homes can be found at the soffit (you may have noticed some pieces have holes in them). What happens on a lot of homes is insulation gets packed into these soffit areas blocking the intake, a homeowner thinks they are doing a good thing insulating their home when in fact they are causing a bigger problem.
The exhaust takes the form of a ridge vent on homes today, giving the air somewhere to escape to. The best analogy for an exhaust is a fireplace. The flue acts as the exhaust; if you do not open it while the fire is burning smoke will come into your home, imagine that this is all the trapped air and vapor in your attic. Once the flue is opened all the smoke gets sucked up and out of the chimney.
Here are some signs to look for in your attic that would indicate you do not have enough ventilation:
Insulation stuffed into soffits
Mold and mildew on rafters and/or floor joists
Rusted nails indicating moisture
All PJ Fitzpatrick roofs come with our ventilation package including SmartVent technology. This places the intake a little further up the roof line above where insulation would be placed in your attic, hence preventing the intake from getting blocked.
The following home had no intake or exhaust. The roofer returned a couple years later and installed a ridge vent, but with no intake the system still does not work correctly. Yes, that’s portabella sized mold spoors you are looking at!