Does A Crawl Space Need A Sump Pump?

Installing sump pump in the crawl space is important even if you don’t face frequent floods. Sometimes, you might be unaware that the groundwater levels could be high in the area. A sump pump detects the rise in water as it fills in the sump basin and automatically starts removing water. If you know that water damage has impacted the house previously, you should install one. Here’s everything you need to know about your crawl space and why it needs a sump pump.

installing sump pump in crawl space

Why is It Important to Install a Sump Pump?

The crawl space is the hollow area between the ground floor and the first floor, which is not easily accessible. It adds more height to the house and creates space for most HVAC, electrical, plumbing, and insulation systems. So, it is necessary to prevent water from accumulating in this area. This shows the importance of having a water removal mechanism in the crawl space

The sump pump is the ideal solution as it can collect and pump out water. It is installed in the lowest part of the basement or crawl space in a “sump pit.” The pit collects water, and the sump pump activates through the floatation system. Once the float switch rises to a certain level with the water, it turns on the sump pump to start removing water.

Sump pumps come in two main types; submersible and pedestal. The submersible pumps sit below the ground, while pedestal sump pumps are usually on the ground level. The two types have slightly different mechanisms for removing the water. 

Why Do You Need a Sump Pump in Crawl Space?

You need a sump pump if there is any water in the crawl space. The presence of water in the basement or crawl space indicates that there is a high risk of water damage. The best way to prevent costly repairs is to install a sump pump that can keep the area from flooding. You can find the best crawl space sump pump, depending on the application. You can also consider having multiple sump pumps or backup pumps to suit your need. Here are some of the various issues that occur due to water in crawl spaces.

  • Mold grows in moist environments, especially in dark and damp areas. It triggers allergic reactions such as sneezing, coughing, and breathing difficulties.
  • Moisture attracts insects, parasites, and pests that damage the property. They tend to live in damp woody environments such as crawl spaces. 
  • Damp air takes more energy to heat and cool than dry air. So, moist crawl spaces increase electricity bills.
  • If there is no water removal method in the crawl space, the water collected in it will then move into the basement. It will flood the basement, causing more property damage.

How to Install a Sump Pump in Crawl Space?

Installation of a crawl space sump pump is quite different from the normal procedure. The ground inside the crawl space may not be even and could create pools of water in low spots. Consider ease of access, drainage plan, and the accessibility to a power source when installing sump pump in crawl space. The installation of the basin and the discharge system is similar to the usual process. But finishing the hole for the basin is different since it is not filled with concrete. It is recommended to add pea gravel up to the brink of the basin to support proper drainage

Make sure that water cannot get near the electrical wires of the sump pump system. It is important to have a check valve attached to the drainage pipe to confirm that water doesn’t flow back. Test the function of this check valve after installation. The drainage pipe coming from the sump pump should go out to a distant location away from the house. It should get the water at least 20 feet away from the foundation. If not, the water will find its way back, and the sump pump needs to remove the water again.

The installation of a crawl space sump pump requires experience and takes quite some time. This is why you should get professional help for the task. The procedure of this installation can be broken down into the following steps.

  1. Find the lowest part of the crawl space and start digging a hole. It should have a depth of about 2 feet on average. But this requirement may differ from one house to another.
  2. Move the soil around the hole to make a slope so that the water around it can run into the pit easily without collecting nearby.
  3. Place a liner before installing the basin. It acts as a barrier that stops mud from clogging the pump. The line needs to have small holes through which groundwater can come in.
  4. Then install the basin tightly against the liber. Do not allow any space for water to build up between the two surfaces, or the water will not drain properly.
  5. If you find any space between the basin and the liner, fill it with stones to prevent dirt from passing through. 
  6. Put an airtight lid on the basin to prevent any radon from seeping into the house through the crawl space. This lid can also block moisture that can damage the crawl space.
  7. The next step is to install the sump pump. Place it upright and connect the necessary wires and drainage lines. This is where the skill of an experienced sump pump installer is important.

Maintenance of a Crawl Space Sump Pump

Scheduled inspection and maintenance are important parts of using a sump pump. It ensures that your sump pump is in proper order to remove water during a possible storm. Examine the pump to check that it is positioned correctly in the basin. Then test is run by pouring some water into the basin to check whether the pump activates and pumps out the water. If it does not function, check the impeller, float switch, valves, and intakes. Sometimes, the float switch stuck inside can prevent the sump pump from starting.

Unclogging any discharge at the vent openings where sediment collects very often. Clean any buildups on the grate that prevent water from moving out. Always keep the sump pump in good working condition. Test the alarm system that informs you if something goes wrong in the system. If you have a backup sump pump, test it as well. 

Other Ways to Protect Your Crawl Space

Removing water from the crawl space is important to keep it dry. There are additional precautionary steps that protect the crawl space and basement from water damage. 

  • Certain basement waterproofing systems prevent wall and floor leaks. It is a drainage channel system beneath the concrete with small holes that allow water to enter the drain. 
  • Some seal systems use hollow PVC basements to collect water and drain it to the sump pump. This prevents hydrostatic water pressure from coming through the wall or floor joints.
  • Vapor barriers help identify any plumbing leaks rather than checking on the ground soil. Install an airtight door that fits around the sump pump to keep the moisture away from the basement.
  • Crawl space fans can remove stale air and radon from the house. It also keeps the room dry through proper air circulation.
  • Using dehumidifiers in crawl spaces filters the air and keeps it dry. Most dehumidifiers contain a water collection that shuts off automatically once they reach the water capacity. They need very little maintenance after installation, which makes the usage easier.

Frequently Asked Questions

What Kind of Sump Pump Do I Need for My Crawl Space?

Sump pumps are of two types: submersible and pedestal pumps. Sump pumps are completely under the ground, while pedestal pumps are partially above. Pedestal pumps are more durable as the motor is positioned out of the water. But it consumes more space than the other type. The submersible pump can handle larger volumes of water and can pump solid particles in the water. You can determine which type of sump pump to use depending on the room of your crawl space. Most homes with an above-average water table need a pump with a power of 1/2 hp. If the water is higher than usual, a 1/3 hp can handle it. 

How Much Does It Cost to Install a Sump Pump?

Installing a sump pump in crawl space costs around $1,000 – $3,000. The prices may vary depending on the complexity of the project and the labor charges. The average price of a sump pump is between $200 and $600. Although this may appear to be expensive, it is definitely worth the cost since it protects the basement from water damage and adds value to the house.

Will a Crawl Space Dry Out on Its Own?

Allowing the crawl space to try on its own is not a good idea. You need to remove all moisture and maintain the humidity at acceptable levels. If not, it damages the structural integrity of the house. You will even find mold and pests attracted into your crawl space. You can use large fans to dry the surfaces by creating air circulation throughout the area. Use dehumidifiers to reduce the relative humidity to a suitable level that doesn’t affect the woodwork. 


Installing sump pump in crawl space is the best way to prevent it from flooding. You might not have to use it often unless you live in an area with heavy rainfall and frequent storms. However, installing a crawl space sump pump is a good idea so that you don’t have to stress over water damage. Call a professional installer to find the correct type of sump pump and get an estimate on the expenses.