Understanding Roof Ventillation

Identifying Potential Ventilation Problems

Roof ventilation is the process by which an attic space will cycle fresh air in and out of its vents.  If you are considering replacing your roof, it is always a good idea to analyze your existing vent system.  You need to ask yourself these questions:

  • Do I have any areas of my home that tend to stay hotter than others?
  • Does your attic get so hot in the summertime, that it is unbearable to go into?
  • Do you know how your existing ventilation system is set up?

So let’s examine these points.  If you have a room, or area of the home that stays hotter than the others, there may be several reasons why this is.  So we need to go through a process of elimination.  First: Do you have sufficient insulation for this room?  You should see 12-15″ of insulation in the attic space above the room.  There should not be any gaps, or voids.  If this is OK, check the duct work next.  Duct work should be large enough to cool the room and you should be able to feel the air move when you put your hand up to the vent.  Small rooms may only need a 6-8″ duct.  Larger rooms may need several ducts.  Make sure there is air moving through the vents.  Finally, check your roof ventilation.  There should be an air hawk, gable or a ridge vent installed, along with sufficient soffit vents.

How to identify your ventilation system

Gable Vents.  These vents are installed by cutting a hole in the exterior attic wall.  The decorative gable vent is installed over the hole.   This vent can be effective, but it is somewhat limited, and can often be inadequate.  The nature of the gable vent is to expel hot air through one location of the attic.  It is more effectively used in tandem with other types of roof vents.   This vent is rarely used anymore in new construction, and is somewhat obselete.  The opening is often large enough to allow birds and other pests inside.

Gable Vent

Gable Vent