Ventilating A Crawl Space: The Best Way

As the name goes, a Crawl space is a small place beneath the roof or the first floors where you have to crawl through. This place is helpful as you can utilize this place to access the plumbing and wiring of the building.

If you have a crawl space in your home or office, you have to take care of it, or it might negatively impact your property. You have to be very specific about maintaining good ventilation in the Crawl Space Vents, and also see that the lace is as clean and hygienic as the interiors of your property.

If you are wondering why these tiny places are so important, we have all your doubts answered. Keep reading and crawl your way through various information you need to have about crawl spaces. .

You can also seek professional help for ventilating your crawl space. Some agencies deal with this sector of work, have the proper knowledge, and are well-equipped to work on crawl spaces.

Crawl Space Ventilation Requirements

The International Residential Code lists things you need to do if you have a crawl space on your property. We have simplified some basic rules that the crawl space ventilation requires:

Ventilated Opening

The IRC states that the crawl space in any property, be it your home or office, must have a one-square-foot size opening at the opening of the structure. Have a look at the following to ensure that the vent has efficient criss-cross air ventilation:

  • A 0.070 inches thick sheet metal plate with a hole in it.
  • A 0.047 inches thick expanded metal sheet plate.
  • Grill or grating made with cast iron.
  • A wire mesh that is corrosion-resistant.

Using these materials will allow the vent to be dry and humidity free. They will not allow moisture to collect within the vent. The opening that you have at either side will help the vent o have proper ventilation and make the space breathable.


The IRC emphasizes having an open-square-foot opening at every 100-150 square feet of space. In order to make the place more suitable, you can cover the ground with a sheet that is vapor resistant. You also need to ensure that each corner of your property has an opening so the air comes in and goes out without any barrier.

Unventilated Crawl Vents

To keep the interiors of the property ward and avoid thermal heat loss, some landowners choose not to have a ventilated crawl space. With the recent guidelines of the IRC, you can allow having an unventilated vent space, given the builder introduces ways by which air can be ventilated in the upper air-conditioned areas and the crawl space. If you want to opt for an unventilated crawl space, ensure that you cover the interiors of the space with materials that are vapor resistant.

Ways Of Ventilation In A Crawl Space

There are various ways that you can choose from while you are ventilating your crawl space. Let us have a look at some basic and most sort our way:

Outside Venting

If you choose to leave the interiors of your crawl space untouched, you can choose to insulate the vent from the outside. All you have to do is cover the outer walls of the space with substances that do not absorb moisture.

However, if you are located in a humid climate, this option is the worst for you, and it is advised that you do not opt for this one.

Installing Dehumidifier

You can also install a dehumidifier to keep your crawl space moisture-free. This dehumidifier is different from what you have installed in your house. This one is only for the crawl space and is by far one of the best options to keep the crawl space free from moisture.

The drawback of the humidifier is you need to get your hands on the extra equipment. Furthermore, you will be needed to maintain the dehumidifier on a regular basis. If the drainage fails, then you need to remove bulk water from the crawl space.

Air Exhaustion To The Outside

According to crawl space ventilation rules in the IRC, it is stated that you can install small exhaust fans so that the inside sir can be pushed outside. If you have a crawl space of 2000 soiree feet, you will need to install 40 cfm exhaust fans.

Air From HVAC Supply System

It is perhaps the most common method that people use. In this method, a little bit of air is pushed into the crawl space from the HVAC system. If your crawl vent has a duct in it, this is probably going to be the best and cheapest way of ventilating the crawl space.

The air that is pushed from the system helps the air inside the space to dry and makes the space moisture free. But the main drawback of this way is that it will put the crawl space under positive pressure while the interior of the property will experience negative pressure.

Benefits Of Well Ventilated Crawl Space

Crawl space is an extremely useful feature in a property, here are some of its benefits that will help you understand its importance:

  • It helps to keep the vent moisture free so that there is no mold growth, fungi or pests.
  • It helps to maintain the air quality
  • It eliminates bad odor from the vents
  • It keeps the space cleans thus you can use it for storage.


Now that you have so much information about crawl space, it is time that you get to work on fixing the crawl space. If you have a hard time figuring out what should be done, you can ask for professional help. The professionals are trained and well-versed in taking care of the crawl space. Call them for assistance to make your crawl space well-functioning and hygienic.