A Step-by-Step Guide to Roof Vent Installation: Static, Turbine, and Ridge Vents
If you are a roofing contractor or a builder, you understand the necessity of roof vents. You also know how important it is to install them correctly.
Whether it is ridge vents, turbine vents, or static vents, proper ventilation is vital to the longevity and efficiency of any metal roof. But installing vents on a metal roof usually comes with a bit of extra pressure since the standing seam is more costly and less forgiving than shingles.
But the good news?
With clear directions, you can correctly and confidently install a roof vent on a metal roof.
In this blog, we’ll provide simple steps to install three vents you’ll likely need to install on a metal roof. *
*Gable vents are another widespread method of venting a roof. However, since they are installed on the gables rather than the metal roof, we won’t include them in this article.
Static Vents
Static vents are (as the name suggests) vents that allow air to escape naturally without the help of moving parts. They are often used for kitchen and bathroom exhaust. Static vents come in various shapes and sizes, including round, box, and goose-neck. Some, like the round vents, may come in two parts – the base layer and the vent itself.
Box vents (also called roof louvers) are one of the most common, so they are the ones we will focus on in this tutorial. However, the same basic principles apply to at least the base layer of all of these venting options.
Here are five steps for installing a static vent on a metal roof.
Step 1: Determine the location of the vent.
If you are doing a reroofing project where ventilation was already installed – skip to the next step.
If the vent is used as general attic ventilation, it should be installed near the ridge of the roof to catch the rising hot air from inside. However, using a static vent for general ventilation is not the most efficient and only works when used with other forms of ventilation. Because of this, we don’t recommend static vents for this purpose.
If the vent is a kitchen or bathroom exhaust, it should be placed as close to that room as possible. Coordinating with the contractor installing the vent inside the house is good to ensure the most efficient placement.
Step 2: Cut the hole through the roof decking and metal
If you are installing a new venting system, you (or the contractor in charge of the inside venting) will need to cut a hole through the roof decking to run the exhaust duct. After completing this, carefully measure and cut a hole in your metal sheet.
Cutting the hole as close to the duct/vent dimensions as possible is essential, as you want the vent to fit snugly. This will decrease the area that needs to be sealed and, consequently, the chances of leaking.
Step 3: Install
Place your vent over the hole/duct and fasten it securely to the roof with screws. If the duct/vent connection is on the inside, ensure they are securely connected using duct tape or clamps.
Step 4: Seal the edges
Seal the edges of the vent with a healthy amount of sealant. Using your finger (or a tool), spread the sealant over the edge of the vent and the roof to ensure an airtight, waterproof seal.
Step 5: Test the vent
Run the bathroom or kitchen fan to ensure everything is working correctly. If you want extra certainty, you can also use the smoke test to ensure no leaks in the sealant. The smoke test is when artificial smoke is pushed through the ventilation system. If there are any gaps or leaks, the smoke will escape, and you can see and repair them.
Turbine Vents
Another method of attic ventilation is turbine vents. Using convection (rising heat), these turbines will ventilate an attic fairly effectively even when there is no wind (although they work better when there is wind).
Turbine vents are an alternative to ridge vents for roofs where ridge venting doesn’t work (e.g., hip roofs, roofs with a pitch under 3/12). Because they aren’t aesthetically pleasing and need maintenance, they aren’t usually a first choice. However, they do perform well when working correctly.
Installing a turbine vent is very similar to installing a box vent, with a few additional steps.
Step 1: Choose a location for the vent.
If you are doing a reroofing project where ventilation was already installed – skip to the next step.
Because turbine vents work via convection, they should be installed near the peak of the roof to catch the rising hot air from inside. They should be placed on the back side of the roof, just sticking over the ridge. This way, they can benefit from any wind.
Step 2: Mark and cut the hole through the roof decking and metal
Carefully mark and cut the hole for the vent base. Like the box vent, it is very important to cut the hole as close to the vent dimensions as possible so you can get a snug fit. This will decrease the area that needs to be sealed and, consequently, the chances of leaking.
Step 3: Install the base
Install the base of the vent into the hole and fasten it securely to the roof with screws.
Step 4: Install the turbine
The turbine is installed on top of the base. Make sure it is properly aligned and secured using screws or clips.
Step 5: Seal the edges
Seal the edges of the vent with a healthy amount of sealant. Using your finger (or a tool), spread the sealant over the edge of the vent and the roof to ensure an airtight, waterproof seal.
Step 6: Test the vent
To ensure that everything is working correctly, check the airflow through the vent. Like the box vent, you can also use the smoke test to make sure there aren’t any leaks in the sealant.
Ridge Vents
Ridge vents are, in most cases, the best venting option for a metal roof. Not only do they vent effectively and efficiently, but ridge vents are by far the most aesthetically pleasing. Additionally, they increase the lifespan of the roof and prevent insects from entering the attic.
However, there are different kinds of ridge vents, and not all are high quality, easy to install, and waterproof.
In this tutorial, we’ll demonstrate how to install our own Snap-Z ridge vent. This product is easy to install, comes with a limited lifetime warranty, and has been tested for snow, rain, and wind up to 110 mph.
Step 1: Measure
Snap a chalk line about 1/8 - 1/16 of an inch above wear the ridge cap will sit.
Step 2: Prepare the vent
Remove the backing on the pre-attached butyl tape. Pull out the overstuffed foam just enough so it fills the gap between the top of the rib and the Snap-Z. Place the Snap-Z along the chalk line.
Step 3: Secure
Fasten the Snap-Z with Type 410 fasteners using the pre-punched fasteners as a guide. Make sure there is at least ½ inch of penetration into the roof decking. Space your fasteners no more than three inches apart.
Step 4: Apply sealant
Apply a generous amount of quality sealant where the Snap-Z joins the panel ribs.
Step 5: Prepare and install the ridge cap
Prepare the gable end of a one-inch open-hemmed ridge cap. Snap the riddle cap into place. Apply sealant to the overlaps. Fasten the ridge cap to the Snap-Z using a least three pop rivets per 10 feet of the ridge cap.
For a video tutorial of this process, click here.
Common Mistakes
We spoke with Edwin, a roofing salesman with 22 years of experience, and these are some common mistakes he identified.
- Not sealing a vent well enough. Be sure to use a generous amount of sealant to seal off any potential problem areas. This is especially important if the hole is a bit too large.
- Using a mesh-style ridge vent. This vent style has an excellent NFA and is a cheaper ridge vent option. However, the good stops there. In reality, it performs very poorly. Because it is made only of mesh, it often gets squeezed by the ridge cap, effectively shutting off its venting capabilities.
Tips & Best Practices
Here are a few tips and best practices Edwin identified from his years of experience that ensure an efficient, effective install.
- Always inspect the ventilation system of the building where you’re installing the roof. It's common (especially in older buildings) that the insulation was placed all the way up against the roof deck. This prevents airflow that is necessary for the ventilation system to work correctly.
- Always measure carefully. As we mentioned previously, metal isn’t very forgiving. Measuring incorrectly might mean needing to replace an entire sheet – and that gets expensive. Don’t rush measuring.
- When sealing a vent, don't start your bead of sealant at the most critical spot (e.g., where the water is most likely to hit). Instead, begin the bead before the critical spot. This creates a continuous bead of sealant across this strike point, making leaks even less likely.
- An odd but effective way to spread sealant without having it stick to your fingers is using saliva. As long as it doesn’t gross you out, it's one of the best ways to get the job done!
- Roof vents are a vital part of roofing, and it is important to install them correctly. If you need ridge vents for your roofing project, we’d love to work with you! Here are a few of the benefits of Snap-Z ridges vents:
- Pre-cut lengths
- Pre-punched fasteners
- Pre-applied butyl tape
- Foam protected by wire mesh for long-term critter protection
- Limited lifetime warranty
- Preserves the look of hidden fasteners
The easy installation Increases your crew’s efficiency, which is a win-win for you and your customers! Get a free quote today!
We hope you found this written tutorial helpful! If you did, you might also be interested in our other blogs, including:
- 7 Reasons Snap-Z Is The Ultimate Standing Seam Ridge Roof Vent
- The Why and How of Proper Roof Ventilation
- 4 Reasons You Need Snap-Z Metal Roof Ridge Vent
If you have further questions or are ready to place your Snap-Z order, give us a call! We look forward to hearing from you!