Drain Cleaning & Unclogging
Open clogged kitchen, bath, laundry and main drains, then find out why the stoppage came back.
Homeowner tips
Basement Floor Drain Backing Up in Westminster, CO
Stop using water in the house. A floor drain is the lowest opening in the plumbing, so a blocked main line shows there first.
By the Westminster Plumbing Co. team ·
First steps
Stop running water. That means no flushing, showers, dishwasher or laundry. Every gallon you add has to go somewhere, and the basement is the lowest place.
Keep people and pets away from the water. Sewage carries bacteria. Wear gloves and boots if you must enter, and keep electrical devices out of the water.
Sewage or groundwater?
Smell and clarity tell you. Sewage is cloudy, smells foul and may carry paper. Groundwater is clearer and has little smell. It may seep up through the slab or cracks after heavy rain.
A meter test also helps. If the water appears when no one is using water, it is not the house plumbing.
Sewage or groundwater
Use this table to sort the two.
| Sign | Sewage backup | Groundwater |
|---|---|---|
| Smell | Foul | Little or earthy |
| Clarity | Cloudy, with paper | Clearer |
| Timing | After flushing or running water | After heavy rain |
| Other drains | Gurgle and slow down | Behave normally |
Where the blockage may be
If several fixtures drain slowly, the main line is blocked. A cleanout near the basement floor lets a plumber reach it. Roots, grease and flushed items are the usual culprits.
The city owns the main under the street. If a manhole is overflowing or neighbors are affected, call wastewater collections. If only your house is backing up, the lateral is likely blocked.
Clearing and prevention
A plumber clears the line with a cable or jets it. A camera shows whether the pipe is damaged. Some homes have a backwater valve that closes against a backup.
Prevent repeat backups by keeping grease and wipes out of drains, watching trees near the lateral and having the line inspected.
Sump pumps and drainage
A sump pump moves groundwater away from the foundation. If the pump fails, water can rise through the slab. Test it before wet seasons, and keep the pit clear.
A battery backup protects against power failures during storms.
Insurance and cleanup
Many standard policies exclude sewer backup unless a rider is added. Ask your insurer. Take photos before cleanup and keep receipts.
Sewage cleanup is a restoration job. Crews wear protective gear, remove affected materials and disinfect the area.
Protecting the room while you wait
Move anything stored on the floor to higher shelves. Wear rubber gloves and boots if you must enter the area, and keep children and pets away from the water. Turn off power to the basement if water is near outlets or appliances, but only from a dry spot.
Open windows for ventilation and run fans if it is safe. Do not use a household vacuum on wastewater. A wet vacuum rated for liquids is the right tool, and the area should be disinfected after cleanup.
Questions to ask the contractor
Ask whether the blockage is in your lateral or in the city main, and request photos or video as proof. A camera inspection after clearing shows the condition of the pipe and whether the problem is likely to come back.
Ask about a backwater valve too. This device lets sewage flow out of the house but blocks it from flowing in. It must be installed correctly and maintained, but it can protect a basement in a city main backup.
Longer-term fixes
Repeated backups usually mean a defect such as a belly, an offset joint or invasive roots. Hydro jetting clears buildup, and lining or replacement fixes the pipe itself. Treating only the symptom leads to another backup.
Schedule routine maintenance if your line has a history of trouble. Annual cleaning is cheaper than cleanup after a flood, and a camera check every few years tracks whether the pipe is getting worse.
When the city main is the cause
If neighbors on your street have the same problem, the blockage may be in the city main. In that case, call the city's wastewater line rather than paying for private clearing. The city dispatches a crew to clear the main and can document the incident.
Take photos and notes of the date, the time and the extent of the backup. Those records help with an insurance claim or a request for city help, and they establish the cause if responsibility is disputed.
After the main is cleared, run water in every fixture to confirm that the house drains normally. A lingering slow drain may point to a second blockage in your own lateral.
A cleanup checklist
Remove standing water with a pump or a wet vacuum, then discard porous items such as cardboard, carpet pad and drywall that sat in sewage. Hard surfaces can be washed with detergent and disinfected with a bleach solution mixed according to the label.
Dry the room fully using fans and a dehumidifier, and keep going until moisture readings drop. Mold can begin within a day or two on damp materials. If the area is large, a restoration crew has the equipment to dry it faster.
Photograph damaged items before you throw them away, and keep receipts for pumps, rentals and disposal. Your insurer may ask for them, even if the policy limits sewer backup coverage.
Why a floor drain backs up first
A basement floor drain sits at the lowest point of the plumbing, so any blockage downstream sends water there before it shows up elsewhere. That makes the drain an early warning, and noticing it quickly can save the floor.
Many floor drains have a removable grate and a trap below it. Lift the grate and look for debris, but wear gloves and avoid reaching in. If the trap is clear and water still rises, the blockage is farther along the line.
Common questions
Answers about floor drain
Air is escaping from a partly blocked line. Stop using water and have the main line checked.
If the blockage is in your lateral, you are. If it is in the city main, the city is. A plumber or the city can tell.
Often only with a rider. Check your policy.
If the water is clear and appears after rain, the pump or the drainage may be at fault.
Related services
Sewer Camera Inspection
Send a camera down the line before a repair, a purchase or a decision about a tree.
Water Damage Restoration
Dry and rebuild a home after a pipe leak, a frozen-pipe burst or a sewer backup.
Keep reading
Sewer smell in the house: causes and fixes
A sewer smell can come from a dry trap, a cracked pipe or a blocked vent. Here is how to narrow it down and when it needs a plumber.
Tree roots in your sewer line
Roots enter a sewer lateral through tiny cracks and joints. Learn the signs, the options and how to protect the line.
Toilet won't flush: what to check
A toilet that will not flush has a short list of causes. Check the tank, the clog and the bigger line before you call.
Drain filling right now?
Stop using water and call. The dispatcher then matches you with a nearby contractor.