Continuous Venting Ridge vs Static/Box Vents: Which is better?

by Jul 31, 2018

Regardless of the situation, all roofs need to be properly ventilated. There are a few differences between Static vents and Continuous Ridge Vents. Deciding which one to put on your roof depends on which one better fits the type and design of your roof. Both static and box vents are exhaust vents for your roof, meaning that these are the vents placed at (or near) the top of a sloped roof for out-flow of air. Both styles, therefore, must also be paired with adequate intake vents – most commonly soffit vents. For more on the basics of attic ventilation and why it’s so important, see our article on Why Proper Attic Ventilation is so Important

Proper roof ventilation not only vents excess heat from your attic to the outdoors, but moisture as well. Moisture is the enemy of materials like lumber, insulation, and the decking of the roof itself. Accumulated moisture is responsible for most of the mold, mildew and rot your home will experience.

Two of the most popular venting methods will be discussed here: ridge vents and box vents. Ridge vents run the length of your roof, while box vents are placed strategically across the roof, often in visible locations.

Box vents and ridge vents keep moisture drawn in by the soffit vents from settling in your attic. This air movement helps prevent the moisture from being absorbed by the insulation and framing. Vents also help dry an attic in the event a leak occurs.

Here we will specifically focus on how box vents and ridge vents differ, how they work, what they do, and when to use them.

What Is a Box Vent?

Historically, the most common type of roof exhaust ventilation are “Static” or “Box” vents (sometimes also called “Turtle Vents” for their appearance). This type of vent is exactly what it sounds like: box shaped vents that remove damaging heat and moisture from the attic. One reason that they are so popular is because they provide a very economical way to ventilate your attic. Box vents are ideal whenever you have an open attic. The vents must be placed very close to the ridge of your roof. Installation is simple, quick, and easy.

Box vents are small boxes (usually 1’ square foot in diameter) that provide enough ventilation for about 150 square feet of roof area. Technically, most box vents can ventilate up to 300 square feet if a vapor barrier is installed as well.

Box vents can take square or circular shapes and can take a short or tall profile. In contrast to ridge vents, box vents are usually installed in groups on the surface of the roof. In most instances, box vents are placed on the side of the roof facing away from the street to improve curb appeal, as box vents are clearly visible.


What Is a Ridge Vent?

Continuous venting ridge is a type of ventilation that allows outward air flow along the ridge or peak of a roof. An opening is cut along the desired ridge line and the continuous ridge vent is laid over the opening and sealed with standard ridge cap shingles. Having the entire ridge line open for venting allows more even airflow out and, in turn, will allow better ventilation of the attic space. Installation is more difficult and time consuming (and therefore more expensive). 

Home designers often struggle with integrating dozens of small boxes protruding from the roof into the curb appeal. For this reason, most pitched roofs today will use a shingle-over type ridge vent, which makes the vent virtually invisible from below.

Some people have concerns with ridge vents because, as a relatively newer type of ventilation, they had a bad reputation in the early days before designs improved. Today, most experts (and our team at Rhoden Roofing agrees), ridge vents are superior products to box vents. However, as they are more expensive to install than box vents, they still are not the vest fit for every situation. There is also more variety in the types of ridge vents. This is important to know for some history of ridge vents and the adaptions that modern ones have made to overcome challenges faced by earlier versions. 

Aluminum Ridge Vents

Aluminum ridge vents were common in the 1980’s and 1990’s because they were easy to install, inexpensive, and effective. Very lightweight, aluminum ridge vents are available in long sections to reduce joints, although color selection is often limited to brown or black.

Aluminum ridge vents are easily dented, clogged, and are notorious for becoming nests for birds. In the past, many aluminum ridge vents used rubber stoppers in the ends to discourage birds and rodents. However, being made from rubber, they rarely outlived the aluminum and fell off, leaving an opening.

Resin and Rubber Ridge Vents

Similar in design to aluminum ridge vents, other materials like resin and rubber are common in modern construction. Most of these ridge vents are designed to be shingled over, but double check before purchasing if you plan to use ridge shingles.

If you accidentally drive fasteners in the wrong place, you can cause a leak instead of preventing one. Always observe and use the nailing flange or nail slots if your resin ridge vents have them. Never drive a fastener into any ridge vent without consulting the directions first.

Corrugated Ridge Vent

Corrugated ridge vent is made in a fashion similar to a cardboard box, which makes the vent inexpensive and strong. Corrugated ridge vent is usually made from heat resistant plastic, which retains its shape well and is very impact resistant.

However, corrugated ridge vents can appear unsightly on shallower roofs and protrude from the ridge. Corrugated ridge vent can usually be shingled over, but always check the installation directions that come with your vent.

Mesh Style Ridge Vent

Mesh style ridge vent uses a semi-dense material to allow the passage of air, but not much else. Mesh ridge vents look and feel like a really long scrubby pad (like you would use for dishes or cleaning), which adds durability and flexibility to the vent.

Mesh ridge vents are about 10” wide and available in very long rolls (usually 25’), limiting joints on long ridges. Mesh ridges are tacked into place with roofing tacks and a ridge cap shingle is installed over it.

Mesh style ridge vents are essentially hidden from view, so the color choices for the roof are endless. Mesh ridge vents are far too dense for a bird or large insects to traverse, which helps it retain its shape.


When Is it Important to Pick One Over the Other?

This is easier to start with when it isn’t very important. Simple roof designs, such as a gable roof with two long slopes and an even attic space, will be served just as comparably by ridge and box vents. Assuming both are installed with proper calculations for intake and exhaust venting area, both will perform well. 

What is already existing? On a roof replacement for a simple roof/attic design where both exhaust vent styles would be adequate, the decision often comes down to cost. If one type of vent is already there during a re-roofing project, and no changes to ventilation are needed to meet building code, going back with the same type of exhaust vent is perfectly okay. If there are no aesthetic preferences, keeping what’s existing saves the cost of changing styles. 

Complex roofs are often served better by ridge vents. Multi-height ridges, interconnected attic spaces, and buildings with many different roof slopes (dormers, connected areas, complex layout) are a prime example to make use of the more even airflow of ridge vents. When sections of an attic risk having low airflow, or areas of ridge are not directly above areas of the intakes, ridge vent helps air flow more evenly through all spaces. This happens with elbow-shaped attics, or in areas where the lower roof is cut off by a porch roof or attached garage that has a separate/divided attic). 

Flat or very low-sloped roofs cannot have ridge vents. Box vents are used in commercial and “low slope” (which most people call “flat”) roofs, like on a school or warehouse. Conversely, very steep roofs are usually done with ridge vents because the steeper the roof slope, the more visible it is from the ground, and most people like the look of ridge vents (essentially invisible) over box vents. 

Aesthetics – where this is the most important, people typically choose ridge vents for the cleaner look. An event venue, for example, may have a very visible roof where box vents would interrupt the look. Alternatively, a home on a corner lot might have both sides of the roof clearly visible from the street so box vents cannot be hidden behind the main ridge of the roof from the street. 

Why are Ridge Vents More Common than Box Vents on Modern Residential Homes?

Ridge vents have come a long way since their introduction in the 1980s. And while still more expensive to install on retrofit applications, they are often cheaper to install on new construction because the vent itself can be cut into the roof deck with a single pass of a circular saw, and the vents themselves come in a roll (or long sections), as opposed to box vents, which are individually installed. Box vents depend on close proximity to the ridge vent for effective operation, which is why you normally see them in the middle section of the roof or higher. Every box vent will require a separate cut, sealant, and adjustments to the surrounding shingles. For many homebuilders, the superior performance of ridge vents is an obvious pick when it is also cheaper to install. 

Ridge vents are installed at the highest point on a roof, so sometimes shingles designed to conform to the pitch of the roof are installed over the vent to improve the appearance. Known as ridge cap shingles, these shingles are heavier than normal shingles, which helps deter wind lift.

Ridge cap shingles are usually available in the same color as the shingles, and require no additional flashing, shingles, or sealant to be effective. They don’t interfere with curb appeal either because they essentially make the vent invisible.

Roofing manufacturers’ warranties require a minimum of one square foot of ventilation for every 150 square feet of attic space for traditional static venting systems, but only one square foot of ventilation for every 300 square feet when a ridge vent system is used. That is a good indication of the difference in efficiency. Using the continuous venting ridge system, when installed properly, can prolong the life of your roof and cut down on energy costs. When applicable, we recommend ridge venting, systems, but in many situations, both are perfectly acceptable exhaust venting solutions.

If you are in the greater Wichita area and looking for a professional opinion on your roofing system, Rhoden Roofing offers free inspections and estimates

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