How Roofers Botch Attic Ventilation

Oct 15, 2021

Correct Attic Ventilation Is Different For Every Home.

But A Lot Of Roofers Treat Ventilation As “One Size Fits All.”

Attic ventilation is a critical aspect of every roofing system. Regrettably, it’s the one aspect of the job that roofers get wrong most often.

That’s a problem. A BIG problem. Poor attic ventilation can wreak serious damage on your home… and even skyrocket your energy bills. Not to mention the problems it can cause with the roof itself—mold, rot, ice dams, shingles failing via overheating, and more.

You’re probably wondering why roofers mess up attic ventilation so badly if it’s so important. To answer that, we’ll first need to explain the RIGHT way to ventilate an attic.


The Attic Ventilation Equation

Appropriate attic ventilation requires an optimum ratio of exhaust ventilation and intake ventilation. If the two aren’t in perfect equilibrium, you’re going to have issues. (More on that in a moment.)

For attic ventilation, the U.S. Federal Housing Administration (FHA) recommends one of the following…

  • If half the ventilation openings are located in the lower half of the attic (typically at the soffit) and half near or at the ridge: One square foot (sq ft) of ventilation area for every 300 sq ft of attic floor area. 
  • If a roof has just soffit vents but no ridge vents: One sq ft of ventilation area for every 150 sq ft of attic floor area.

Within those parameters, your roofer has to hit the correct balance of intake ventilation and exhaust ventilation. Without suitable exhaust ventilation, hot air can’t escape. Without suitable intake ventilation, air will simply circulate across the top of the attic space, while the air at the bottom stays stagnant.

Circulation is also restricted when there are vents on only one side of the attic. It’s similar to what would happen if you opened the windows on only one side of your house on a breezy day.

Since every home is different, achieving intake-exhaust balance requires a thorough analysis of the roof and attic. And that’s where most roofers get things wrong.

2 Ways Roofers Mess Up Attic Ventilation

Roofers Mess Up Attic VentilationA lot of roofing companies you call either A) won’t do an attic inspection or B) give your attic just a passing glance.

Instead of a custom solution based on YOUR needs, these companies take a “one-size-fits-all” method. They utilize the same ventilation system for every customer’s home… regardless of its size and needs.

Here are two common improper ventilation setups we see:

  1. More Exhaust Than Intake: If your attic has more exhaust ventilation than intake, your attic essentially sucks the conditioned air in your home up through unsealed openings such as vents and recessed lighting fixtures. As such, you have to run your air conditioning more to keep your home cool.
  2. Two Exhaust Systems: When a roofer puts in two exhaust systems, the more powerful exhaust will pull air from the weaker system. This can leave certain parts of your attic unventilated.  

How To Make Sure Your Roofer Gets Your Ventilation Right

Want to know if the roofer you’re considering will properly vent your attic?

First, make note of whether the roofing contractor conducts an attic inspection. If they don’t, we strongly recommend you find another company. If they can’t be bothered to inspect your attic, what kinds of corners do you think they’ll cut on the actual job?

If the roofer DOES perform an attic inspection, it’s a step in the right direction. But it’s not a guarantee that you’ll get the proper solution. So after the roofer inspects your attic, ask the roofer the following questions…

  1. Do you abide by FHA recommendations of one sq ft of attic ventilation area for every 150 to 300 sq ft of attic floor area?
  2. Could you describe your plan for making sure my attic has the optimal balance of exhaust and intake ventilation?
  3. Do you plan to install more than one form of exhaust ventilation? (If the roofer says “yes”? Run away!)

Asking these questions will weed out the roofers who get attic ventilation wrong—and ensure you pick the roofer who gets it RIGHT.

Free Attic Inspection & Roofing Quote

At Clemens Home Solutions, we conduct a meticulous attic analysis to determine exactly what you need. We’ll review our findings with you so you can see precisely what kind of ventilation is right for your home.

If that sounds like the kind of thorough company you’re looking for, reach out today to schedule your free roofing quote. We would be honored to hear from you.

Schedule a Free Estimate