Every time a roof is replaced, the existing attic exhaust vents should also be replaced, even if those vents appear to be in good condition and reusable. 

A question I field during the Q&A session of our seminars is: “If we’re installing a new roof and the existing attic exhaust vents look to be in pretty good condition, can we reinstall them with the brand new roof?”

It has been AirVent’s longstanding position that reusing attic exhaust vents should not be done — no matter the condition they might appear to be in. Shingle manufacturers say the same thing. 

The Asphalt Roofing Manufacturers Association is the professional organization representing shingle manufacturers. In its Technical Bulletin "Why Ventilation is Important," ARMA says:

“When reroofing, replace the ventilation devices within the field of the roof (that is, static vents, ridge vents). It is possible to retain intake and exhaust vents not in the field of the roof (that is, soffit vents, gable vents) provided they remain functional when reroofing is complete.”

I find it telling that shingle manufacturers do not want reused attic exhaust vents installed with their brand-new shingles.

Here are the reasons attic exhaust vents should not be reused.

1. During the removal of the attic exhaust vents, it’s possible that damage can occur to the vents. Damaged attic exhaust vents cannot be expected to perform as intended.
2. The attic exhaust vents will have holes in them from the original fasteners used to install them the first time around. Can we be 100% sure that the existing fastening holes will be used again without leaving exposed, unprotected holes during the second installation? Will any unprotected holes risk weather entry? And will the fastening holes used during the first installation be sufficiently secure to hold the vent in place the second time around?
3. Simply from a “value of the purchase” perspective, remember that someone is paying thousands of dollars for a brand new roof. Why cheapen the value of that investment with reused attic exhaust vents?

Sometimes I hear from the field that during an insurance claim to replace a storm-damaged roof, the insurance adjuster is requesting to reuse the existing attic exhaust vents. We direct anyone who asks us for assistance in this matter to the ARMA Technical Bulletin mentioned above. Our rationale: If the maker of the brand new shingles cautions against reusing attic exhaust vents, protect the investment by installing brand new attic exhaust vents.