How To Install Roof Ventilators

How To Install Roof Ventilators

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James
February 23, 2022
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Is your home getting enough ventilation? If your attic feels musty, hot, or uncomfortable, you need to install a roof vent, or ventilator, that will better circulate the air.

What’s a roof vent?

A roof vent is a unit that gets installed on your roof, and it’s basically the foundation of your attic ventilation system. It also protects your roof against damage. 

Let’s explore everything you need to know about roof ventilators. We’ll also look at how to install roof ventilators easily and without having to call a professional. 

Why Are Roof Ventilators Important? 

How To Install Roof Ventilators

Your home needs a roof ventilator because of how it ensures your attic remains properly ventilated. If you don’t install one, you risk various problems in your home and roof. Here are benefits of installing a roof vent.

  • It prevents mold and mildew growth. This is because mold and mildew thrive in damp areas where there’s not a lot of ventilation.
  • It reduces your energy usage. Roof ventilators help to remove hot air from your attic, which not only makes it more comfortable to be inside your house but it prevents your HVAC from having to work very hard, therefore helping you save money on your energy bill.
  • It prevents ice dams. When warm air melts ice and snow on your roof, this water can accumulate at the roof edges. This causes ice dams which damage the roof. By ensuring that hot air is removed from the attic, the ice and snow won’t melt, preventing water damage.
  • It prevents an accumulation of heat. High amounts of heat in the attic can cause damage to wooden structural components in your roof.  

Four Main Types Of Roof Ventilators

There are four main types of roof ventilators.

Turbine vents

How To Install Roof Ventilators

Known as “whirly birds,” turbine vents are designed with slats to encourage greater air circulation. How they work is that they contain aluminum blades inside an aluminum covering. The blades rotate as a result of wind from outside the house, then they draw air up from inside the attic, releasing it from the house. 

Power vents

How To Install Roof Ventilators
RP4200 Picture

These roof vents are circular in shape and are low-profile in design so that they aren’t visible. They get installed near the top of the roof and make use of electricity to draw hot air from your attic so that it stays cool.

However, during the colder months you’ll have to use power vents with a humidistat to prevent humidity accumulating in your attic. 

Ridge vent

How To Install Roof Ventilators

This type of vent is interesting because it gets installed into the roof ridge and it runs the length of it, which prevents it from being noticeable from the ground. It requires a filter otherwise debris, water, and insects can gain access into it and end up in your attic. 

A ridge vent works well because it gets installed at the roof’s highest peak. This means that it’s in the perfect spot to allow hot air to escape from the attic. Since this vent runs along the roof line’s length, it has enough surface area to effectively release large amounts of hot air. 

Box vents

How To Install Roof Ventilators

Box vents are a popular type of roof vent. They look like small boxes that get installed on the roof. They don’t make use of electricity and they work most effectively with open-attic plans. They work by moving stale air out of the attic, therefore removing moisture and heat from the space.

How To Install Roof Ventilators 

You can install a roof ventilator without calling the pros, but just make sure that you read the instructions for your specific ventilator as installation instructions can vary. However, there are some general tips to consider.

The tools you’ll need:

  • Roof vent 
  • Ruler
  • Drill and drill bit 
  • Ladder 
  • Marking pencil 
  • Nails 
  • Hammer 
  • Pry bar 
  • Jigsaw (or reciprocating saw) 

How to install roof ventilators: 

  1. Go into your attic and find the spot where you want to install the roof vent.
  2. Drill a hole through the center of the area. Make sure you leave the drill bit through the roof – this will enable you to find it from outside. 
  3. Place your ladder against the roof and climb onto the roof to find the drill bit. 
  4. Measure the open area of your vent (this is the part that sits flush with your roof) with a ruler. 
  5. With the drill bit as your center, use a ruler and pencil to get the same measurement of your vent’s open area, and make this mark on your roof. 
  6. With your jigsaw, cut along the lines you’ve measured. Cut through the shingles and wood underneath. 
  7. Use a pry bar to ensure you loosen the shingles around the hole. 
  8. Flip the vent upside down and put a bead of caulk onto the flange. 
  9. Slide the sides and top of your vent beneath the surrounding shingles. Make sure you leave the bottom side of the vent so that it’s exposed and lay it over the shingles. 
  10. Then, you can attach the vent to the roofing structure with nails. 
  11. Make sure you secure the loose shingles around the area with more nails. 

How To Install Different Types Of Vents 

How To Install Roof Ventilators

How To Install A Ridge Vent 

First, you will have to remove cap shingles along the ridge. Then follow these tips:

  1. Cut away sheathing with a circular saw, about one inch down on either side of the ridge. Stop about three inches from the end of the roof on either side.  
  2. Be careful not to cut into the ridge board or trusses. 
  3. Remove the sheathing and install the ridge vent by fastening one piece of vent at a time and then attaching the next piece onto it. Nail each piece as you go through the process. 
  4. Cap the ends. If you have a shingle-over-roof vent, you will apply ridge cap shingles over the vent and then fasten them with two-inch nails. 

How To Install A Turbine Vent 

  1. You will mark a spot near the ridge, then cut away shingles as well as underlayment. 
  2. Use a saber saw to cut a hole that’s the same size as the vent diameter. 
  3. Use some plastic roof cement underneath the vent, then put it over the hole and slip the flange underneath the top-side shingles. Place the flange over the down-slope shingles. 
  4. Use nails to secure the vent’s base and cover the nail heads with some roofing cement to make them waterproof.

How To Install A Powered Vent 

  1. Inside the attic, insert a nail one-third of the way down from the ridge between the two rafters. 
  2. Then, on the roof you will cut a hole that’s the same size as the vent diameter. 
  3. Fasten the flange underneath the top-side layer of shingles, and place the flange on top of the bottom shingles. Use roofing cement to seal it up.  

How To Install A Box Vent

  1. Position the box vent near the ridge of the roof. 
  2. With a hook blade, mark the spot on the roof where you want to install the box vent. 
  3. With the straight edge of the box vent in line with the shingles so it will be straight, line it up on the mark you made. 
  4. With your blade, cut through the shingles, and across the top, then remove the shingles so that the box vent will be able to sit in the roof.
  5. Remove the nails that were underneath the shingles. 
  6. You will also have to remove nails from some of the surrounding shingles, as the box vent flange will slide underneath them, but be careful not to damage the shingles. 
  7. You can then secure the box vent to the roof with nails. 

How To Calculate How Much Roof Ventilation You Need 

One of the things you’ll have to consider when purchasing a roof vent is how much ventilation you actually need in your attic.

Vents get rated according to their net free area, or the amount of space for air to flow in or out.

Therefore, calculate the attic ventilation that’s required by figuring out the square footage of your attic floor (width x length). Then compare this to the total required net free area (NFA) of the vent. Doing this calculation will help you to know how many vents are required for your home. 

Related Questions 

What is a solar-powered vent?

A solar-powered vent uses the sun’s rays for power but it doesn’t usually manage to hold a charge for the whole day. This means your air conditioner will have to work harder.

What is a hook blade for roofing? 

A hook blade is a utility knife blade with hooks on the edges. It’s used in roofing because it can cut through thick materials, such as shingles. 

Conclusion 

If your roof doesn’t have a vent installed, this can cause your attic space to become hot and uncomfortable.

A roof vent is important to ensure the health of your roof, so make sure that you have one installed. You don’t have to leave this task to the pros – you can do it yourself, as we’ve featured the installation steps to follow.

Reference Articles:

James

James Weldon is a professional roofing contractor with many years of experience on the job. He does not only handle large projects and provide excellent services for his company’s many clients; James Weldon also dedicates his spare time to teaching others useful tricks of the trade. Using BuildCampus as an avenue to reach many roofers and aspiring roofing contractors, James Weldon continues to provide high-quality educational posts and buying recommendations for anyone who visits the website.