Dryer Venting Through Roof: Is it Advisable?

As a homeowner, you often have to make difficult decisions. One of the most difficult decisions to make is whether you should vent a dryer through the roof or the wall. Some people vent their dryers through the roof, and there are many who does this through an outside wall. But which is recommended?

The best way to vent a dryer is through the outside wall. Generally, it is not advisable to vent a dryer through the roof because it can cause moisture buildup and mold in the attic. and fire hazards due to blockage of roof vent and pipes as a result of lint collection.

But there are situations where venting through the roof is your only option.

Let’s first see the reasons why venting a dryer through the roof is not advisable and how to do it properly if you have no other options.

Reasons why dryer vent through the roof is generally not advised

A dryer vent installed on a roof

One of the most common mistakes people make is installing the dryer vent on the roof, so the moist air gets on the outside area of the house through the roof. There are several reasons why this is generally a bad idea!

Water risks

If it rains and chances are every now and then it will rain, a roof dryer vent could give you a lot of trouble. While dryer vents do come with caps that prevent rainwater from getting into them they can’t prevent rain 100%. If you live in a windy area and the vents face the direction of the wind, there is good chance water will enter the dryer vents. Since these vents are routed through the attic, this water leakage can cause condensation and mold problems in the attic and cause damage to the insulation, wood, and things there.

Roof dryer vents are harder to clean

One of the main issues with roof dryer vents is that they are difficult to clean since you will have to get on the roof to do that. Dryer vents need to be cleaned often to avoid lint build-up. So installing them on the roof makes the cleaning process difficult, making a person reluctant to clean it, which further leads to air blockage and even fire hazards. Therefore, it is always better to install the vent on an outside wall than on the roof.

The moisure drainage can be a hassle

Dryer vents installed on the roof go vertical compared to a wall vent parallel to the ceiling. There is always the chance of moisture condensation in the vent pipes. A wall vent is normally pitched to the outside to drain any water as a result of condensation. However, for roof vents, the condensed water will move back into the dryer since the whole piping is installed vertically. This can be troublesome.

Fire hazards

A dryer vented through the roof is more prone to fire hazards than one vented through the wall. This is more true in the case of 2-story houses. In such cases, the vent pipes will have to a long way to the roof, assuming the dryer is on the ground floor. This adds load to the dryer’s exhaust system. It is difficult for the dryer to blow away all the moisture and lint content in the exhaust air all the way to the top. This can cause blockage in the vent pipes leading to fire hazards.

Steps for installation of dryer vent through the roof

Even if installing your dryer vent through the roof is not the best option, in some cases, it might be the only option you have. And since you want to install your roof dryer vent, it is essential to install it the right way because you want to avoid any additional issues such a system might give you. So here is how to install a dryer vent through the roof the right way!

1. Choose the right location

The vent opening location should be less than 25 feet away from the dryer you have in your home. You want this distance to be as short as your space allows you. The location of your vent will depend greatly on the way your home is built but if you keep it less than 25 feet, your dryer should be able to handle it efficiently.

2. Prepare the outside hole

Before you cut into the roof to create the hole you need you will have to trace it with a marker or pencil from the attic. Measure your vent and trace the size of it on the roof so you know exactly where to cut it. You can drill a hole of one or two inches so you can place a saw that will help you cut the vent opening hole. Make sure to follow the outline you created so your hole will fit your vent perfectly. You can do all this from the attic, without getting on top of the roof yet.

3. Install the dryer vent

To add a duct elbow you will need to get on top of the roof. First of all, you will have to cover the hole perimeter with roofing tar. Next, remove any shingles or other pieces of material that could cover the hole. Add the pipe of the vent through the hole and place the flashing on the shingles.

During this installation, you will have to nail the flashing to the roof with nails of 1 inch, made especially for roofs. Make sure to cover the edges with tar and attach the cap. The cap of the vent will be attached according to the model you have but most of them just snap on and off with no struggle.

You will have to connect the tube of the vent to the dryer as well. Do this by securing the tube on the fittings that your dryer comes with and follow the instructions of the product as each dryer is different. 

4. Insulate the vent

Insulation is also very important in order to reduce condensation as much as possible. You can use pipe insulation and metal foil tape to insulate the pipe that goes through your attic. If you live in a primarily cold climate, it is essential to insulate the pipe.

5. Check the security of the joints

Finally, you will have to check the joints and empower them with metal foil tape to make sure there will be no leaks. Check especially the joint between the vent and the duct.

Should a roof dryer vent have a screen?

If your dryer vent is installed on the roof of your home, it is recommended to avoid adding a screen to it. However, you will see that most vents don’t come with a screen anyway, so this is not something you should consider.

The main reason why you shouldn’t add a screen to your roof dryer is that it will prevent the lint from escaping properly. Lint will clog over time, and your vent will not work properly due to the screen, which is why it is better not to add such an accessory.

If your vent accumulates too much lint, you expose your home to a fire risk. Because of this lint layer, air will not flow smoothly through your venting system and the heating element can get to temperatures of 190 degrees F. If this heat gets in contact with a lint clump, the risk of a fire happening is very high.

Roof vent suggestions for dryer

Duraflo 6013BR Roof Dryer Vent Flap

  • Excellent UV performance
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  • Attractive low profile styling
  • Flexible flange will not crack on installation, even in extreme cold

How to clean a roof dryer vent

Cleaning your roof dryer vent is a task you will most likely have to do several times a year or as often as it is necessary. The better you control condensation, the less you will have to clean this vent. Cleaning the dryer vent regularly is part of proper maintenance that you shouldn’t ignore if you want to benefit from your system in the long run.

If you do need to clean your rooftop dryer vent, here is how you can do it with less struggle!

Method 1

You will need to turn the dryer on and get on top of the roof if you want to clean the rooftop vent. To get on top of the roof, you will need to use a ladder and make sure you do this safely.

Once you are on top of the roof, you will need to remove the cap of the vent and the screen if you use a screen. You can use a metal stick or an unraveled coat hanger to stick it inside the vent. Get the lint out with such a tool and go back to the dryer to turn it off.

Method 2

You can also clean the dryer vent by taking it off the dryer and sticking a vacuum tube inside of it. To do that, you will have to remove the tube of the dryer from the dryer and turn your vacuum on before you stick it inside. The stronger your vacuum is, the easier it will be to clean the tube and the vent. Your vacuum should pull most of the lint and debris inside the tube and from the vent exit.

This method tends to be safer since you will not have to get on top of the roof. You can do it all from the inside of your house and with the tools you already have.

How to prevent dryer vents on the roof from clogging

As we mentioned previously, the best thing to do is to prevent your rooftop dryer vent from clogging in the first place.

Not using a screen will help airflow go through the vent easier and reduce clogging risks. The cap of the dryer should be enough to keep birds out and still allow the lint to escape your system.

Long drying cycles also facilitate clogging. It is a lot more efficient to run your dryer in cycles of 30 to 40 minutes and give it a break before you restart it. Long drying cycles increase moisture levels and attract more debris as well as more lint, creating the perfect conditions for clogging.


If your home structure doesn’t allow you to install a dryer vent on any other wall but the rooftop, this guide should give you the important information that you need to avoid the hassle. Rooftop dryer vents can be functional and efficient as long as they are well maintained. If you have trouble installing or cleaning your dryer vent, talk to a professional, so you don’t take any risks. It is important to keep an eye on the condensation level and to reduce mold risk as much as possible if you install the dryer vent through the rooftop.

Additional reading:

Charles John

Experienced HVAC technician with 8 years of experience in the industry. Capable of handling all sorts of heating and cooling equipment as well as proficient in operational management, construction-related techniques such as preventative maintenance, electrical troubleshooting and AutoCAD

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