In fact, if you ever hear rodents running around in your attic
or if your ceiling is cracked and yellow... chances are you have
a problem with attic ventilation. Also, if you have high utility
bills in both the summer and winter you could have a problem
with attic ventilation. The roof just makes the house water
tight. The space between the insulation and the roof is of
course the attic and it needs to be ventillated to prevent heat
build up in the summer, (up to 140-degrees) and moisture build
up in the winter. That's why roof and soffet vents are
installed... to keep the air circulating and prevent the build
up of heat and moisture. Proper ventillation starts with fresh
air being drawn in through the soffitt vents which you will find
underneath the eafes of your house. Make sure the vent openings
on the soffits have not been inadvertently covered with
insulation... this happens a lot during new home construction.
The roof vents are what pull the air up through the attic...
There are several different types