Should I replace my ridge vent when I get a new roof?

Yes, in most cases the ridge vent should be replaced, or at least reviewed, when you get a new roof. The ridge is where the roofer finishes the job, the vent is part of how the new roof breathes, and a new roof over an attic that cannot ventilate leaves the ventilation problem in place. Treat the vent as a line item in the roofing contract, not an afterthought.

Why the ridge is the time to deal with it

A ridge vent sits under the cap shingles at the peak. When the old roof comes off, that area is exposed anyway, so the extra cost of a new vent is mostly the material. Fixing a failing vent later means breaking into a finished roof again.

A vent that is old, cracked or brittle, or that was never matched to the soffit intake, is a good candidate for replacement. If it is in good shape, ask the roofer to say so in writing and to explain how it will be reused.

Ask for a ventilation check, not just a vent

New roofing does not fix a ventilation problem; it can hide one. Before the quote, ask the roofer to look at the attic and answer these questions in the estimate:

• Is there continuous intake at the eaves? Virginia Cooperative Extension says most homes should have a combination of a continuous ridge vent along the peak of the roof and continuous soffit vents at the eaves to provide the most effective ventilation.^[1]
• Is there enough vent area? As a general guide Extension gives approximately 1 ft2 of net vent opening for every 150 ft2 of ceiling or attic space, and says to check your local code.^[1]
• Is insulation blocking the intake? The Building America guide says baffles and insulation dams should be installed to keep insulation out of the soffit vents and to direct cooling air flow from the soffit vents up along the underside of the roof deck to the ridge vents.^[2]
• Where do the bath fans and dryer vent? They should go outdoors, not into the attic.

ENERGY STAR advises hiring a professional where there is little or no attic ventilation,^[3] and the same list includes wet or damp insulation, indicating a leaky roof,^[3] and moldy or rotted attic rafters or floor joists, indicating moisture problems.^[3] If you see those, ask for the cause to be dealt with in the same project.

Be cautious if the roofer wants to drop the soffit intake or change the vent layout. A roofer should be able to explain the plan and how much vent area it provides.

Permits and deck repairs

Virginia's building code exempts from permit application the replacement of an unlimited amount of roof covering or siding in Group R-3, R-4, or R-5 provided the building or structure is not in an area where the nominal design wind speed is greater than 100 miles per hour,^[4] and the replacement of 256 square feet (23.78 m2) or less of roof decking in Group R-3, R-4, or R-5, with a fire-rating exception.^[4] The building official may still require an application for roofing in a historic district: the code says an application for a permit may be required by the building official for the installation of replacement siding, roofing, and windows in buildings within a historic district.^[4] Confirm with your building department and ask the roofer who is responsible for any permit.

Putting it in the contract

DPOR advises homeowners to get at least three written bids or estimates using identical plans and specifications,^[5] so make the ridge vent part of that specification: the type and length of vent, the cap shingles, and any intake work. Virginia's Board for Contractors requires the contract to contain a listing of specified materials and work to be performed^[6] and a statement of assurance that the contractor will comply with all local requirements for building permits, inspections, and zoning.^[6] Do not accept "ventilation as needed" with no detail.

When to call a licensed pro

For all of it. A new roof is a licensed job, and ridge work is done at the highest and most exposed part of the house. DPOR says that if the work you are considering is valued at $1,000 or more, a valid Virginia Contractor’s License is required,^[5] and a re-roof will almost always be well over that. Check the licence before you sign.

To learn how the vent works, read what a ridge vent does. For what a repair costs, see how much ridge vent repair costs in Virginia. Browse roofing repair answers or roofing services, and when you are ready, describe the job once to hear from licensed local roofers.