Installing a ridge vent on a shingled roof can provide much-needed ventilation to your attic space. Proper attic ventilation helps remove excess heat and moisture, preventing issues like ice dams, mold growth and premature roof deterioration. While the project requires some carpentry skills and roofing know-how, it can typically be completed in a weekend by an experienced DIYer.
Below is a step-by-step guide on how to install a ridge vent on a shingled roof:
Assess Your Roof and Plan the Project
Before starting any work, carefully inspect your roof to determine if it is suitable for a ridge vent installation. Consider the following:
Roof Pitch – Ridge vents require a roof pitch of at least 3/12. Flatter roofs are not good candidates.
Roof Structure – Make sure roof rafters extend to the ridge. Vents need solid framing to attach to.
Roofing Shingles – Ridge vents can be installed on asphalt, wood shake, slate or metal shingles. The vent cuts into the roof, so shingles must be replaceable.
Existing Ventilation – Assess current attic ventilation. Supplement ridge vents with soffit intake vents if needed.
Roof Condition – Repair any moisture damage, leaks or rot before installing new vents.
Once you confirm the roof is suitable, measure to determine the required vent size. Available ridge vent products range from 4 ft to 20 ft sections. Measure your roof’s ridge length and buy enough vent to cover at least 50% of the total ridge.
Gather necessary materials and tools:
- Ridge vent system
- Roofing nails or screws
- Circular saw with fine-toothed blade
- Utility knife
- Caulk and roofing cement
- Hammer, tin snips, tape measure, ladder, safety equipment
Carefully review the vent manufacturer’s installation instructions. Plan workflow and safety precautions. Installation is easiest with an assistant to help position and secure the vent. Check weather and schedule several days of clear conditions.
Prepare the Roof
Proper prep work is crucial for successful ridge vent installation. Follow these steps:
- Set ladder safely and remove existing ridge cap shingles with a utility knife or circular saw. Cut back existing roofing about 6-12 inches from the roof ridge. Sweep away any debris.
- Expose sheathing by removing roofing felt/tar paper along the ridge. Cut a slot about 1 inch wide on each side of the ridge pole. This allows the vent to sit low in the opening.
- Cut and remove roof sheathing in the center gap between those side slots. The width of roof decking to remove equals your vent’s specified opening width. Remove 2-3 feet at a time as you move along the ridge.
- Confirm rafter bays are clear and unblocked from the soffit to ridge. Scrape mortar or spray foam away from rafter ends if needed to ensure airflow.
- Install roof underlayment on each side of the ridge opening. Use heavyweight felt paper or synthetic underlayment. This protects the roof decking exposed by vent installation.
With prep work complete, the roof is ready for the new ridge vent.
Install the Ridge Vent System
Follow the vent manufacturer’s step-by-step instructions closely during installation:
- Position the first vent section at one end of the roof ridge, aligned with the outer roof edge. The vent must cover the entire ridge – do not stop vent sections short.
- Fasten the vent in place by nailing or screwing through the vent side flanges. Use the specified fastener type and follow fastener spacing guidelines.
- Use tin snips to tailor the vent at the end of ridge terminations and at intersections with vertical walls. The vent must fit tightly to roof surfaces.
- Join additional vent sections using connectors provided. Attach each section before moving along the ridge. removable tape can also temporarily hold vent sections in place.
- Inspect underside of vent periodically to ensure proper nail/screw penetration. Fasteners must securely attach the vent through the roof sheathing.
- Caulk the full perimeter of the vent using roofing cement. This helps create a weatherproof seal. Apply caulk anywhere the vent meets the roof.
- Install a foam vent closure strip along the ridge pole, under the vent, to seal any gaps at the peak.
- Cap ridge vent ends using provided end pieces, caulk, roofing cement or metal flashing. This prevents water infiltration at the vent edges.
Thoroughly seal and secure the vent to ensure it sheds water and allows optimal airflow. Check for any unevenness along the ridge and use caulk to fill gaps as needed.
Replace Shingles and Complete Roofing
The final installation steps involve re-shingling:
- Starting at one end, install new roof shingles up to the ridge vent. Overlap shingles with the vent flange as specified by building codes.
- Trim shingles flush with the vent using a utility knife. Shingle edges must rest flat on the vent surface. Avoid any shingle overhang.
- Use a hammer to secure shingle edges down onto the vent flange. Apply roofing cement for enhanced water protection.
- Complete shingling the second roof side in the same manner, overlapping ridge vent flanges.
- Seal any exposed shingle nail heads with roofing cement. Fill gaps around protruding roof vents/pipes with caulk.
- Inspect and clean up the roof area thoroughly. Sweep away any nails, shingle scraps or debris.
- Extend piping from downspouts if needed to direct water away from the roof. Test that water flows away from the house.
Allow roofing cement and caulk to fully cure before walking on the new roof. The ridge vent improves ventilation as soon as it is installed, but it takes a rain or two for the roof to fully seal and prevent any leaks. Monitor the roof after storms and repair any dripping, gaps or loose shingles.
FAQs About Ridge Vent Installation
Below are some common questions and answers about installing ridge vents:
Should I close gable vents when adding a ridge vent?
Yes, the presence of ridge vents eliminates the need for gable vents. Leaving gable vents open creates shortcuts for airflow, reducing the effectiveness of the ridge vent.
Can I install a ridge vent on a flat roof?
No, ridge vents require a sloped roof to work properly. For flat roofs, consider installation of rooftop turbine vents instead.
What width ridge vent do I need?
Match the installed width to the vent manufacturer’s recommended air opening for your roof pitch and climate. Wider is generally better for optimal airflow.
How do I cut the ridge board when installing a vent?
In most cases, you can cut out a section of ridge board the same width as the vent opening without compromising roof structure or ventilation effectiveness.
Can I install ridge vents on a roof without soffit vents?
It is not recommended. Balanced intake and exhaust ventilation achieves the best moisture control and cooling. Add soffit vents or under-eave vents.
How do I attach ridge vent to architectural shingles?
Follow manufacturer instructions to adhere self-sealing architectural shingle tabs to the vent flange. Avoid nailing through the tabs.
Should I caulk the entire ridge vent perimeter?
Yes, use roofing cement to seal the full perimeter for optimal weatherproofing. Pay special attention tocaulking vent end pieces and junctions.
How long does ridge vent installation take?
The process typically takes 2 full days – 1 day for roof prep work and 1 day for vent installation and re-shingling. The timeline can vary based on roof complexity.
Conclusion
Installing a ridge vent brings much-needed airflow into your attic, helping manage temperature and moisture. The project extends shingle life, reduces ice dams, and improves indoor comfort. With careful planning and application of roofing best practices, an experienced DIYer can successfully tackle a ridge vent installation project. Just be sure to complete prep work thoroughly, follow manufacturer instructions closely, and use proper safety precautions. Your improved attic ventilation will provide benefits for many years to come.