Sump Pit Sealing: A Crucial Step for Radon Safety

What is a sump pit, how it works, and how to make sure its not causing a problem.

What Is a Sump Basin

A sump pit, also known as a sump basin or sump well, is an essential component of a basement or crawlspace drainage system designed to manage and collect water. Here’s what you need to know about sump pits:

Key Features:

• Location: Positioned at the lowest point in the basement or crawlspace, the sump pit efficiently gathers water.
• Material: Typically constructed from plastic, fiberglass, or concrete to ensure durability and resistance to corrosion.
• Size: Varies, but generally large enough to hold a significant amount of water until it can be pumped out.

Functions:

• Water Collection: The primary role of a sump pit is to collect water from groundwater seepage, rain, snowmelt, or plumbing leaks.
• Preventing Flooding: By collecting water, the sump pit helps prevent basement or crawlspace flooding and water damage.
• Facilitating Pumping: Acts as the reservoir for the sump pump, which pumps the collected water out and away from the building, typically to a storm drain or dry well.

How It Works:

1. Water Accumulation: Water enters the sump pit through drains or natural seepage.
2. Activation of Sump Pump: When the water level in the sump pit reaches a certain height, a float switch activates the sump pump.
3. Pumping Out Water: The sump pump then removes the water from the pit, discharging it away from the building to prevent water accumulation and potential flooding.

A sump pit is a crucial part of any effective sump pump system, playing a vital role in protecting your basement or crawlspace from water damage by efficiently managing water collection and discharge.

Proper Sealing

Essentially a sump pit is just a big whole in the ground and because of this, if left unsealed can be a major entry point for not only radon, but other soil gases, odors, and even bugs. While sealing is essential, it is seldom a standalone fix to radon problems.

Building Code

Canadas building code (section A-9.13.4. Soil Gas Control) requires that sump pits must be made airtight. Unfortunately, even when built correctly improper maintenance can cause leaks to the seal. Because sump pits require maintenance every time a pit is opened care must be taken to ensure it is re sealed correctly.

Best Practices for Sealing

Your sump pit is protecting your home from flooding – we want to make sure its airtight but don’t want to stop it from doing its job.

1. Airtight
   • Make sure there are no leaks
2. Accessible
   • Sump pumps require annual maintenance and should be visually inspected a few times a year. A proper should seal ensure it can be quickly opened in an emergency, easily checked and tested for annual maintenance, and easy to put back together to maintain the seal.
3. Safe
   • Ensure the seal is strong enough that if someone steps on it they wont fall in – We don’t want a trap door in the mechanical room.

Our Process

1. Identify the Problem

What’s wrong with this sump basin?

1. Not Airtight – leak point in and around the pit
2. Trap Door – If someone stepped here without looking, they might have a bad day
3. Check Valve – No one way valve on the water discharge.
4. Small access point – the small opening would make it tricky to replace the pump

2. Adjustments to Existing Pit

• Pump has been removed
• While we are here – lets clean the pit and remove and debris that may cause a future problem
• Access has been enlarged for easier maintenance.

3. Install Check Valve

Required by most sump pump manufacturers, this not only will extend the life of the sump pump but is crucial if the sump may be used for depressurization. Without it, the pit may pull in outdoor air and which can cause plumbing problems during cold temperatures.

4. Re Install the Pump and Prep

• Pump is re-installed
• Floor is marked where the new lid will be installed
• Sealant applied to where the lid will sit

5. Base Ring Installed

Base Ring is sealed to the concrete, another layer of sealant is applied from the inside.

This part of the lid is permanently attached. As you can see, the pump is far more accessible than it was before.

6. Lid and Gaskets Installed

The lid is sealed, label and gaskets are installed. In this case pressure field diagnostic testing revealed this was a suitable location for the suction point. Note this is not always the case and ASD should never be applied to the sump pit without proper testing.

Disconnect point for the system installed to ensure easy access, viewing port to check on water levels and check tab (the red button on the bottom) to quickly insert a hose for yearly sump pump maintenance. The lid we used here is the Jackel SMR16101-CV.

FAQ