3 Best Ways to Clean Attic Soffit Vents

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

Soffit vents are effective at helping to ventilate an attic. However, to be effective at bringing fresh air into an attic, they need to be kept clean and free of obstructions. What is the best way to clean attic soffit vents?

The best way to clean attic soffit vents will depend on how high it is from the ground, the type of soffit vent to be cleaned, the material it is made of, and whether there is a heavy accumulation of dirt or debris. The best ways include using compressed air, water pressure cleaners, and brooms.

This article will present the different situations that you may encounter in cleaning attic soffit vents. It will provide you with information on the different types of soffit vents and the particular cleaning challenges that each presents. So, if you want to find the best way to clean your soffit vents, read on, and find out how.

A Basic Rundown of Soffit Vents

The soffit is the underside of the eaves of a roof. Soffit vents are called as such because they are attached directly to the soffit. They are also known as under-eave vents.

Being placed on the soffit allows for air to enter the attic from the lowest possible point. This way, the air drawn in can be channeled through the attic and released at a higher venting point. This external vent can be a roof ridge vent or a side-gable vent. The airflow that is created helps to cool the attic in the summer. In winter, it helps to keep moisture from condensing in the attic.

Since it is recommended that a house have 30 square inches (19.5 square millimeters) of soffit venting per 100 square feet (9.3 square meters) of attic space, the average home will have several soffit vents. These can run continuously along the soffit or be placed individually in intervals. While a soffit vent has no moving parts, it still requires maintenance.

Since a soffit vent is drawing in outside air into the attic, dirt and debris will accumulate. The rate of this accumulation will depend on your local environmental conditions. The frequency of winds in your area—even the presence of foliage and other landscaping decisions can affect the amount of dirt and debris on a soffit vent.

Additionally, the number of soffit vents can also affect how fast they can become dirty. The fewer the number of soffit vents, the more air that will be drawn through them. The more air passes, the faster the accumulation of ambient dirt and dust.

What Type of Soffit Vent Do You Have?

The specific type of soffit vent that you have on your home will play a large role in determining the best way to clean them.

Soffit Style

Individual Soffit Vents

This soffit vent is a grill placed on the soffit of the roof’s eave. The vents are spaced to be in between each joist.

Due to their grill-type design and the fact that they are spaced widely between each other, they tend to accumulate more dirt than other soffit vents. This accumulation is intensified if the venting higher up the attic consists of electric fan vents constantly drawing air in from the soffit vents.

Continuous Soffit Vents

A continuous soffit vent will run around the entire soffit. As such, a greater amount of air enters your attic. It also distributes it more uniformly.

Continuous soffit vents rely on strips of grills. Some will have an overlay that is placed on top of the grills. The overlay can be for aesthetic purposes, but it can also have the practical effect of discouraging vermin from accessing the attic through the vent.

While being continuous results in greater air flows into the attic, it also spreads out the intake. As such, dirt and debris will not concentrate so heavily throughout the vent. However, when it comes to cleaning, instead of dealing with vent grills every few feet, you now have to contend with a continuous grill around the entire house along the soffit.

Perforated Soffit Vents

These types of soffit vents do not use the grill design. Instead, they rely on panels with small perforations on them to allow the air to flow. The design is the best way to prevent rodents or insects from accessing your attic through the vent.

However, since the holes are much smaller than the spacing on a grill, dirt and debris can accumulate faster. Perforated soffit vents will usually require cleaning with greater frequency than other soffit vents.

Circular Soffit Vents

These soffit vents are smaller and circular. They can use either a grill-type vent opening or one that is perforated. Due to their small diameter, many would have to be present to draw in sufficient air into your attic to be used effectively.

The large number required and their small form-factor can make circular soffit vents a hassle to clean.

Soffit Material

Soffit vents are made of a variety of materials. These materials can be aluminum, stainless steel, PVC, and resin. While all materials are chosen for their resilience, when harsher cleaning is required, PVC and resin vents need more care than aluminum and stainless steel ones.

Other Key Conditions to Consider with Soffit Vent Cleaning

The style and material of a soffit vent are fundamental to how you approach cleaning each one. However, other factors also come into play when cleaning your soffit vents.

Height

How high your soffit is from the ground plays a role in how difficult it will be to clean them. On single-story homes, the soffit vents can be reached using a standard ladder. Two-story homes require an extension ladder to reach the soffit.

Accessibility

The area immediately below the eaves of your roof is not always clear of obstacles. There could be shrubbery or other forms of landscaping. There could also be air conditioning units and other items that make placing a ladder difficult. These obstructions need to be taken into consideration before you begin cleaning your soffit vents.

Current State

Soffit vents are made to last for years, with many being used for decades. As tough and resilient as they are, they can fall into various states of disrepair. Screws holding the vent in place can become loose. Paint can begin to chip away.

In the case of perforated soffit vents, if they are painted when the house’s exterior is painted, the paint can clog the venting holes and make them inefficient or ineffective.

Mold or mildew also can form on the vent openings. If that is the case, you will need to make sure that your preferred cleaning method takes this into account. For mold and mildew, using a mild detergent or bleach and water solution can remove the problem.

Analyzing your soffit vents’ current state before you start the cleaning process will make you able to assess the magnitude of the cleaning job at hand properly. It will allow you to determine the equipment you need correctly and to adequately set aside sufficient time to complete the task in a single day.

Using Compressed Air

Compressed air is one of the most effective ways of cleaning your soffit vents. It is effective with all types of soffit vents.

If you already own an air compressor, using it for this purpose can be quite useful. The main issues that arise when using compressed air to clean soffit vents have to do with getting the air nozzle close enough to the vent to blast them clean. It implies having a portable air compressor that is light enough to carry with you on a ladder.

Alternatively, it means having a full-sized compressor that you can reposition below the roof overhang and have a long enough hose to reach the vents.

When using a portable or full-size compressor in this way while on a ladder, you need to exercise extreme caution and care—it would be wise to have somebody assisting you as a ladder spotter. This person could also help you keep the air hose from becoming entangled with the ladder or becoming jarred on other obstacles.

To clean soffit vents with compressed air, you should bring the air nozzle one to six inches (2.5 to 15 cm) from the vent. Using medium pressure, in short bursts, apply air to the entire surface of the vent. In areas where there is excessive dirt build-up, apply more bursts until it is blown away.

The angle at which you hold the nozzle to the vent is essential. Pointing the nozzle straight into the vent openings is not advisable. It is best to do your best to angle the nozzle so that as much of the dirt and debris that you are blowing away flies off to the side or downward. In other words, you want to avoid as much as possible blowing the dirt and residue into the duct and your attic.

Compressed air can be very effective at blowing away dirt and debris from a vent, but it cannot do anything for rust stains or mold and mildew build-up. If you spot any of those conditions on your vent, you need to treat them after blowing the vent clean.

Carrying a spray bottle with a solution of water and dishwashing detergent would be handy for this. You can spray the solution on the affected areas and allow it to rest for a minute or two. Then, using a cloth or cleaning brush, scrub the affected area. Once the stain or mildew is removed, wipe down one more time with a clean cloth.

Using a Pressure Washer

Using a pressure washer to clean your soffit vents is another effective way. Unlike using an air compressor, you don’t have to be as close to the vent to get effective results when using a pressure washer.

That said, the closer that you can get to the vent, the better. The reason is that the closer you get, the lower the water pressure you have to use on the vent.

Ideally, soffit vents should be cleaned using a low-pressure nozzle connected to your pressure washer. The reason for this is not because a high-pressure stream would damage your vent. Rather, it is to prevent unnecessary amounts of water from entering your attic.

To get the best results and avoid the risk of water penetrating your attic, you should sway the nozzle from side to side, avoiding concentrating too much pressure for an extended period in one area of your vent.

A first pass should be given using nothing but water. This action removes the surface dirt and grime from the vents.

Another pass then follows this, this time using medium pressure incorporating a mild detergent to the stream. This action removes deeper dirt and also removes stains from mold and mildew. A final low-pressure pass using nothing but water is applied to remove any remaining detergent.

Using a pressure washer with a sufficiently long extension nozzle can eliminate the need to use a ladder. A pressure washer used in this fashion is perhaps the best way to clean soffit vents on two-story homes.

If, however, you do not have a sufficiently long extension to reach the vents and you do have to use a ladder, be careful not to place it on a slippery surface. Also, be careful where the residual splashback from the stream lands to avoid your face.

Using Brooms and Brushes

An “old school” but effective way to clean soffit vents involves using brooms and brushes. The process is as simple as it sounds. You use long-handled brooms and brushes to brush and scrub dirt and debris from your soffit vent.

An extended-length handle may eliminate the need to get up on a ladder to clean the vents using this method on single-story homes.

Similar to using compressed air, since the cleaning action used is dry, any stains or mildew on the vents will not be removed using brooms and brushes. In those cases, just as with the compressed air method, you will need to carry a soap and water solution with you to apply and scrub away such stains.

When Should You Clean Your Soffit Vents?

It is important not only to know how to clean your soffit vents but also when to clean them.

A general rule would be once per year. If you live in a climate with harsh winters, it is best to do so in mid to late autumn, before winter starts. Doing so will allow your soffit vents to be clean and free from potential obstructions when temperatures drop, and the chance for forming ice dams on your roof increases.

Ice dams form when rising heat from your roof melts snow and ice unevenly. The top melts and refreezes as it reaches the bottom of the roof. Eventually, ridges form, trapping more water and refreezing it.

When this accumulation eventually does melt, it can penetrate roof shingles and leak into your walls. By having clean and unobstructed soffit vents, the heat dissipation from your roof is more even, thus avoiding the creation of ice dams.

Precautions to Take When Cleaning Attic Soffit Vents

Whenever you clean your soffit vents, regardless of which method you use, there are certain precautions that you should always take.

Wear Eye Protection

If you are using compressed air, a pressure washer, or a brush, debris will be coming off the soffit vent that you are cleaning. This debris can potentially strike your eyes and cause damage. Wearing protective lenses or goggles will prevent this.

Wear a Face Mask

The same way that you should wear eye protection, so too should you wear a face mask. Some of the dirt, dust, and debris that will come off your soffit vent could be irritating to your lungs. This issue is magnified if you suffer from allergies or asthma.

Additionally, if there is the risk of mold or mildew growth on the soffit vents you are cleaning, you want to keep that out of your respiratory system.

Implement Proper Ladder Safety

If you use a ladder to clean your soffit vents, remember always to set the ladder on a stable surface. Many times, the substrate immediately below the roof eave consists of a patch of dirt with landscaping. This surface could be saturated with water. Never place a ladder on a surface that does not provide it with stability.

If you are climbing a ladder with either a pressure washer or air compressor hose, ensure that the hose does not get snarled on your legs or feet.

Use Only Mild Detergents

When using detergents to clean your soffit vents, make sure that you use mild detergents. Doing so will prevent any discoloration of the vent or soffit. Any runoff that splashes on your walls or lands on the ground below will not cause stains or harm shrubs or grasses.

Conclusion

Cleaning your soffit vents should be a task that is performed at least once per year. If you live in areas with harsh winters, this is even more important to prevent ice dams.

Using compressed air, using a pressure washer, or relying on elbow grease with extended brooms and brushes are the three most effective methods to clean your soffit vents.