How do you stop a backflow from a floor drain?

What causes backflow from a floor drain?

Backflow from a floor drain occurs when there is a blockage or backup in the main sewer line. This causes wastewater to back up through the floor drain and into the building. There are a few common causes of backflow from floor drains:

• Main sewer line blockage – Tree roots, grease buildup, or collapsed pipes can block the main sewer line and prevent wastewater from flowing out of the building. This backed up sewage has nowhere to go but up through the floor drain.
• Undersized drain pipes – If the drain pipes in the building are too narrow to handle the flow of wastewater, it can cause backups and backflow into the floor drain.
• Improper drain slope – Drain pipes need to be sloped properly to allow wastewater to flow out by gravity. If the pipes are flat or sag, it allows wastewater to back up.
• High water table – A high groundwater table can cause water to flow back up through the floor drain and into the building.
• Sewer overload – Heavy rain or excessive water use in the building can overload the municipal sewer system and cause backflows.

Signs of backflow from a floor drain

There are a few signs that indicate you may be experiencing backflow from a floor drain:

• Water or sewage coming up through the drain – This is the most obvious sign of backflow. You may see dirty water, sewage, or toilet paper coming up from the floor drain.
• Gurgling sounds – Listen for gurgling sounds or see bubbles coming from the drain as wastewater backs up.
• Sewage odors – You may notice foul odors coming from the drain if sewage is backing up.
• Multiple drains affected – If more than one floor drain has backflow, it indicates a larger system problem rather than just one clogged drain.
• Toilets and sinks draining slowly – Slow drainage throughout the building can indicate a main sewer line backup.
• Standing water around floor drain – Water that remains pooled around the drain may indicate backflow.

How to stop backflow from a floor drain

If you notice signs of backflow from a floor drain, take action right away to stop it. Here are the steps to stop backflow:

1. Turn off water supply – Locate the main shut off valve for the building and turn off the water supply. This will prevent more water from entering the drainage system.
2. Plug the floor drain – Use a rubber stopper, inflatable drain plug, or watertight seal to temporarily plug the floor drain opening and prevent more backflow.
3. Contact a professional – Call a licensed plumber or drain technician to inspect the drain pipes and sewer line. They can rod the drain, clear obstructions, and make repairs.
4. Install a backflow preventer – Your plumber may recommend installing a gate valve or swing check valve in the floor drain. This allows water to flow out but prevents backflow.
5. Repair sewer lines – If the main sewer line is damaged or blocked, the plumbers will need to clear the clog or repair or replace sewer pipes.
6. Treat backflow contamination – If sewage has overflowed, you’ll need to thoroughly disinfect the affected areas to ensure there is no contamination.
7. Improve drainage slope – The plumber may recommend re-sloping pipes or drain replacements to improve flow and prevent future backflow.

How to choose the right backflow preventer

There are a few types of backflow preventers that can be installed to stop future backflow through floor drains:

Gate Valve

A gate valve allows you to manually open or close the drain pipe. Keeping it closed blocks backflow, but you have to remember to open it when needed for drainage.

Swing Check Valve

This valve allows water to flow out but automatically swings shut to prevent backflow. It requires no manual operation.

Overflow Drainplug

This fitting goes in the drain and seals when water tries to back up. It also lets normal drainage flow through.

Air Gap Fitting

An air gap is a vertical separation between the drain and sewer line. It prevents backflow while still allowing drainage.

When choosing a backflow preventer, consider:

• Type of drainage system
• Severity of backflow issue
• Ease of access for maintenance
• Local plumbing codes

Your plumber can recommend the best solution based on the specific problem and drainage system.

How to maintain backflow prevention devices

Once you have a backflow preventer installed, follow these tips to maintain it:

• Test periodically – Gate valves and check valves should be tested annually to ensure they seal properly.
• Inspect for obstructions – Remove any debris that could obstruct the backflow preventer and impede drainage.
• Check air gaps – Ensure air gaps meet the proper code requirements and are not blocked.
• Follow manufacturer instructions – Clean, service, and inspect devices according to the manufacturer recommendations.
• Repair leaks – Fix any leaking pipes or fittings near floor drains as leaking water can contribute to backflow problems.

Properly maintaining backflow preventers helps ensure they continue working effectively. Contact a plumber if you have any concerns about their operation.

Steps for cleaning up a backflow incident

If you have a backflow incident from the floor drain, follow these steps for cleanup:

1. Wear protective equipment – Wear rubber gloves, boots, goggles, and protective clothing when cleaning up sewage.
2. Stop the backflow – Plug the drain and turn off the water supply to stop further backflow.
3. Remove solid materials – Scoop or pump out any solid sewage or materials.
4. Disinfect surfaces – Scrub affected surfaces with hot soapy water and disinfectant.
5. Deodorize – Apply deodorizers or odor-removing chemicals to affected areas.
6. Extract water – Use wet vacs or extraction equipment to remove standing water.
7. Dry areas – Use dehumidifiers, fans, and air movers to dry out affected carpets, baseboards, and other absorbent materials.
8. Replace damaged items – Contaminated carpeting, drywall, furniture, or other porous materials may need to be replaced.
9. Check for hidden damage – Look for damage behind walls, under floors and behind cabinets.

Extensive water damage or contamination may require professional remediation services. Contact your insurance provider about coverage.

How to prevent backflow from floor drains

Here are some tips to help prevent backflow from floor drains in the future:

• Install backflow preventers – Adding a gate valve, swing check valve or air gap fitting provides an extra barrier.
• Regular drain maintenance – Clean floor drains regularly to remove grease, soap buildup and other debris that can lead to clogs.
• Avoid pouring fats or oils down the drain – Grease and oils can coat pipes and cause blockages.
• Don’t pour chemicals down drains – Harsh chemicals can damage pipes over time.
• Check for drain pipe issues – Inspect drain pipes regularly for cracks, improper sloping or other problems needing repair.
• Update old or damaged plumbing – If pipes are aging or damaged, replace them to prevent backups.
• Install cleanouts – Outdoor sewer line cleanouts allow access to rod or clear main drain clogs.
• Landscape and re-grade properly – Ensure the ground slopes away from the building’s foundation to prevent excess moisture in soils.
• Update sewer lines if undersized – Larger drain pipes are less likely to clog and backup.

Prevention is the best way to avoid costly backflow incidents. Being proactive about maintenance and plumbing improvements can minimize your risk.

When to call a professional for backflow issues

In some cases of backflow, a professional plumber may be needed. Call a plumber if:

• You experience recurrent backflow incidents
• Backflow release sewage or hazardous materials
• The floor drain has a strong unpleasant odor
• You find indoor sinkholes or soil subsidence near exterior drains
• The problem persists after attempting DIY drain cleaning
• Interior flooding covers a large area
• Backflow is accompanied by a main sewer line clog
• You need backflow devices installed or repaired
• Video camera inspection of drain lines is required
• Sections of drain pipe need repair or replacement
• Professional cleaning/disinfection of flooded areas is needed

Though some minor backflow can be managed with DIY methods, extensive backflow, repeated incidents or backflows of hazardous materials call for a professional.

The pros have the expertise and equipment to fully diagnose problems and provide the needed plumbing repairs to stop recurrent backflow problems.

Costs to repair backflow floor drain issues

Here are typical costs to repair backflow issues from a floor drain:

Service	Cost
Basic main line drain cleaning	$100 – $250
Sewer camera inspection	$175 – $300
Floor drain plugs	$5 – $20 each
Backflow drain valve installation	$150 – $350
Trenchless sewer pipe repair	$2,000 – $8,000
Sewer line replacement	$4,000 – $12,000
Biohazard cleaning/disinfection	$500 – $5,000

There may also be additional costs for drywall/flooring removal and replacement if needed after extensive backflow flooding. Insurance policies may cover some costs if the backflow incident causes major home damage.

Conclusion

Backflow from a floor drain can cause serious water and sanitation hazards if left unchecked. Being aware of the signs and causes of backflow can help detect issues early before major damage occurs. In many cases, a professional plumber is needed to properly diagnose and repair recurrent backflow problems. Investing in proper maintenance and backflow prevention devices can help minimize the risk of expensive sewer backups or contamination incidents. With the right plumbing repairs and prevention strategy, your home’s drainage system can work smoothly for years to come.