Vents in the Attic

November 1, 2018

Last month ducts … now let’s discuss attic vents! There are many vents in an attic that serve a variety of important purposes for your home. The number and type of vents will be determined by a variety of things, such as when the house was built, the size of the home, and various plumbing fixtures and appliances installed in the home and attic. These vents will be connected to different types of pipes or ducts… or not connected – ha! I inspect a lot of homes where the pipe or duct is disconnected in the attic and, therefore, the vent is not performing the function for which it is intended.

Vents have pipes or ducts to which they are connected. Writing out this article about the different types of vents, I am finding that I want to write much more about each one so that a more brief article is not realistic or beneficial to you, so let’s break them down into more bite-sized articles to understand each one. Go up into your attic and look at all the different types of pipe and ducts that are going through your roof decking. In addition, look at the air vents in the roof decking or ridge that have no pipe or duct connected to it. The list below breaks down for you the different types of vents in an attic.

  • Plumbing Vents
  • Exhaust Vents
  • Appliance Vents
  • Fireplace Vents
  • Attic Ventilation Vents

The plumbing vent (also known as a vent stack) is generally PVC pipe and is installed and flashed / sealed through the roof decking. Plumbing vents provide fresh air pressure in the plumbing system to the drain pipes which remove water and waste and help it flow properly to the sewer or septic tank. These vents also remove sewer gas and odors to prevent them from entering the home. If the vent pipe is broken or covered, the drain may not function properly and gas and odors may be present in the home.

Inspecting a lot of homes, I often find that some vents stacks will be capped or covered which prevents the vents from working to allow air into the system. The end of the vent stack seen above the roof needs to be uncovered. Placing a screen over this is permissible, but not a cap or cover. In addition, where the vent stack penetrates the roof decking, the pipe must be properly flashed and sealed to prevent any possible moisture penetration into the decking or attic. We’ve talked about flashing before, and it’s an important part of every vent installed in the roof decking and the flashing needs to monitored and maintained properly.

That’s just a little about the plumbing vents, and we’ve got a lot more to discuss regarding the other vents. I know you just can’t wait to hear about exhaust vents, which is exhausting (corny joke, I know!)… so until next month, stay properly ventilated my friends!

Lee Rushing

Lee Rushing (TREC #21601) is licensed with the Texas Real Estate Commission as a Professional Real Estate Inspector with ProVantage Inspections, PLLC.