What Causes Water to Come Up Through Basement Floor Drains?

As a home improvement professional with over 10 years of experience, I often get calls from distressed homeowners dealing with water bubbling up from their basement floor drains. This flooding can lead to thousands in damage if left unchecked.

In this comprehensive guide, I‘ll draw from my expertise to explore the common causes of basement drain backups and how to correctly diagnose the issue. I‘ll also provide temporary fixes to stop the flooding, along with proven methods to prevent future occurrences.

Why Water Comes Through Floor Drains

Before we dive into solutions, it‘s important to understand what causes water to flow upwards into your basement through the floor drains in the first place.

There are three main ways this can happen:

1. Blocked Drain Pipes

The most common reason is a partial or complete clog in the drain pipe itself. Drains connect to larger pipes that move wastewater away from your home. If these become blocked, water has nowhere to go.

Causes of clogged basement drain pipes include:

• Built-up debris, dirt, or grease
• Damaged or improperly installed pipes
• Intruding tree roots
• Collapsed or shifted pipes

In over 20% of homes, drain clogs stem from tree roots entering through cracks or joints in the pipes. Roots grow towards water and can completely choke drains over time.

2. Backed Up Sewer Lines

Municipal sewer lines that your home connects into can also become blocked, causing wastewater to back up into your basement drains.

This is more common in cities with aging sewer systems. Causes include:

• Pipe breaks or cracks
• Settling/shifting pipes
• Grease or soap buildup
• Tree root invasions
• Undersized sewers
• Excess stormwater entering the system

According to the EPA, there are an estimated 240,000 sewer overflows each year across the US.

3. High Water Table

Heavy rains or wet seasons can cause the water table around your home to rise. If your drainage system sits higher than the saturated ground, water will flow upwards into your basement.

This is most common with shallow drains or when downspouts empty too close to your home‘s foundation.

Now let‘s move on to diagnosing the specific cause of backups in your home‘s floor drains.

How to Diagnose the Source of the Problem

Finding the exact root of the problem is crucial for determining the right fixes. Start by running through this checklist:

Inspect Visible Pipes and Drains

Use a flashlight to peer down into your basement floor drains. Check for any debris, grease, soap buildup, or tree roots that may be clogging the pipes.

Also inspect any other visible plumbing to see if tree roots have entered or caused damage. Burst pipes or joint separations can allow roots to intrude.

Check for Sinkholes and Grading Issues

Walk around your home‘s exterior foundation. Look for areas where the ground is settling or pulling away from the foundation walls. This signals that soil is eroding downwards, which can rupture drain pipes.

Also check that the ground slopes away from your house on all sides. A minimum of 6 inches of fall per 10 feet is recommended. Flat or negative grading causes rainwater to pool next to your home‘s foundation.

Inspect Plumbing Fixtures and Appliances

Leaks from indoor plumbing fixtures or appliances allow water to seep downwards into your basement floor drain.

Thoroughly check water heaters, under sinks, around toilets, and under washing machines for any slow drips or pooling water. Damaged seals or loose connections may be to blame.

Test Sump Pumps

For homes with groundwater issues, improperly functioning sump pumps are often the culprit for water backups.

Examine your sump pump and test that it turns on when water fills the basin. Make sure the discharge pipe is clear. Old pumps may lack the power to keep up.

Check Backflow Prevention

Many homes have backflow valves installed on the main sewer line to prevent wastewater backups. Make sure these valves are properly installed and functioning.

A cracked or faulty backflow preventer can allow sewage to reverse flow into your basement when clogs occur further down the municipal sewer line.

Professional Drain Inspections

If your visual inspections don‘t reveal an obvious cause, call a professional plumber to diagnose the issue.

A camera scope fed down your drain line can identify obstructions and damage like intruding tree roots, cracks, and pipe separations.

Plumbers can also pinpoint leaks using special dye added to appliance water. The dye will then leak out at the problem area.

4 Quick Fixes to Stop Water Coming Through Drains

Taking steps to stop the water flow gives you time to properly diagnose and repair the problem. Here are 4 common quick fixes:

Plunging the Drain

Forces created by plunging can dislodge minor obstructions like grease buildup or debris clogs. Use a heavy-duty sink plunger and plug any other nearby drains with a damp cloth first.

Snaking the Drain Pipe

A mechanical auger or drain snake fed down the pipe can physically remove blockages like tree root masses. Be sure to wear gloves and eye protection.

Pumping Out Water

Submersible pumps, wet/dry vacuums, or sump pumps all remove standing water from your basement. Reduce water levels before tackling repairs.

Sealing the Drain

Temporarily plug or dam the floor drain with an inflatable stopper or rubber mat. This prevents more water entering the basement during heavy rains.

These quick fixes buy you time but won‘t solve the underlying problem. Let‘s explore permanent solutions.

6 Methods to Prevent Future Sewage Backups

Once you‘ve diagnosed the specific cause, implement the right solutions to prevent repeated backups through floor drains:

Install an Interior Drainage System

A properly sized sump pump provides the fastest way to pump away incoming groundwater before it floods your basement.

I recommend a cast iron sump pit and a 1/2 HP pump for most homes. Installing a backup sump and battery system prevents failure during outages.

Connecting the sump pump to a perimeter drainage system or drainage tiles around your basement walls provides added protection by diverting groundwater away from your foundation.

Repair Structural Issues

Fix any foundational cracks or gaps that allow water to seep into your basement. Injecting epoxy fillers or polyurethane foams can seal openings.

A professional waterproofing contractor can also install an interior drainage membrane along your foundation walls to direct seepage into your sump pit.

Clear Tree Roots and Restore Pipes

Severely clogged, damaged, or improperly sloped drain pipes allow water backups and root intrusions. Replacing compromised sections of pipe or laying new drainage lines prevents obstructions.

A plumber can also use mechanical rodding or hydro-jetting to clear out tree roots if the infestation is not too severe.

Install a Backflow Preventer

Adding a backflow prevention device on your home’s main sewer line prevents wastewater from reversing back into your basement when clogs occur further down the municipal sewer pipes.

I recommend having a licensed plumber install the backflow preventer to ensure proper placement and functionality. Annually check that the device is working properly.

Improve Perimeter Grading

Regrading the soil to create a slope of at least 6 inches per 10 feet carrying water away from your foundation keeps groundwater from saturating the soil near your home.

Downspouts and gutters should also direct rainwater at least 5 feet away from your home. Extensions, splashblocks, or drainage pipes help prevent puddling.

Waterproof Basement Walls

Applying waterproof paints or membrane coatings to exterior foundation walls prevents moisture seepage into your basement.

Closed-cell spray foam adds insulating value while also blocking moisture migration through concrete pores.

Interior drainage membranes like Delta MS also wick moisture down to your sump pump system.

4 Tips to Avoid Future Sewage Backups

Implementing these best practices helps avoid repeated backup occurrences:

• Annually inspect and service sump pumps, backflow valves, and drains.
• Stagger use of appliances to avoid overloading drains.
• Keep all drains clear of debris, soap residue, and grease.
• Ensure gutters and downspouts divert rainwater away from your home.
• Install a sump pump battery backup to operate during power outages.
• Consider enrolling in insurance programs that cover sewer and drain repairs.

Following the advice in this guide helps homeowners like you diagnose drainage issues, stop basement flooding, and prevent future headaches from clogged drains and sewer backups.

I hope you found my home improvement expertise helpful. Don‘t hesitate to reach out if you have any other basement waterproofing or drainage questions!