When the drains
back up
Every other water loss begins with stopping the water. This one begins with getting people out of the room, and the reason is what is in the water rather than how much of it there is.
Sewage that appears on a floor has almost always been under that floor first. By the time you can see it, it has already been somewhere you cannot look.
Why the first move is
to leave the room
Water from a drain, a toilet trap or a sewer line is Category 3: grossly contaminated water, treated as a health risk regardless of how clear it looks or how little of it there is. It carries bacteria, viruses and parasites from every fixture in the building, and where the backup came from the municipal side, from every building on that line.
The risk is not only what you touch. Contaminated water that gets agitated, by a vacuum, a fan, a mop or somebody walking through it, goes into the air as fine droplets. So the sequence here is the opposite of the usual one. You are not trying to get the water up quickly. You are trying to stop it spreading through the house while it sits still.
The second reason to stay out
A backup comes up at the lowest opening it can find, and to get there it travelled the length of the lateral under the slab. The water in the room is the last part of the event, not the first.
What to do in the first hour
In order, and the order is doing real work.
- 01
Stop using every fixture in the house, including the ones upstairs
This is the step that gets skipped. If the blockage is in the main line, everything draining anywhere in the building is delivered to the room that is already flooding: a shower upstairs, a washing machine mid cycle, a toilet somebody flushes without thinking.
- 02
Keep everybody out, and close the door
Children, anybody pregnant, anybody with a weakened immune system, and pets in particular. A dog will walk through it and then through the rest of the house, which turns one contaminated room into several.
- 03
Cut the power to the area, from outside the area
Outlets in a slab house sit low on the wall, close to the level standing water reaches. Turn off the circuits serving that room at the panel, without crossing the wet floor to get there. If the panel is on the far side of the water, leave the room.
- 04
Ventilate to the outside, not through the house
Open a window in the affected room and let the air leave the building there. Do not put a fan in the doorway blowing the room out into a hallway, and do not run the air conditioning, because the return will pull that air into the ducts.
- 05
Do not use a household vacuum
A wet vacuum, a carpet shampooer or a shop vacuum with a standard filter moves the water and aerosolises what is in it at the same time, and the machine is then contaminated itself. Leave the water where it is.
- 06
Photograph everything before anything moves
Wide shots from the doorway, then the fixture it came up through, the high water line on walls and cabinets, and anything of value standing in it. These are the only record of how far it went, because within a day the material that shows the extent will have been removed.
- 07
Report it, and use the word sewage
When you call the carrier, say plainly that it was a drain or sewer backup rather than a leak. The category changes what gets removed and whether the policy responds at all, and being vague at the start creates an avoidable argument later.
Important
Contaminated water that is disturbed goes into the air.
Keep children, pets and anyone with a weakened immune system out until the area has been contained.
- 01
No vacuum
Do not vacuum it.
- 02
No shampoo
Do not shampoo it.
- 03
No fans indoors
Do not blow a fan across it into the rest of the house.
- 04
No air conditioning
Do not run the air conditioning while the area is open.
What comes out instead
of being dried
After a clean water loss the question is what can be dried in place. Here the question is different, because a disinfectant only works on the surface it can reach, and porous material holds contamination inside itself rather than on its face. Drying it leaves you with dry contaminated material.
Water that came up through a floor drain also gets under the flooring and along the slab penetration. So the material comes up, the substrate is cleaned and treated, and drying starts after that. Drying first bakes the problem in.
- 01
Removed
Carpet and pad, drywall to a cut line above the water line, batt insulation, particleboard and MDF, cabinet toe kicks and any cabinet base that stood in it, laminate and engineered flooring. Anything that swelled has already taken the water inside.
- 02
Usually cleaned and kept
Tile and grout, the slab itself, glass, metal, and framing lumber that can be cleaned, treated and then dried to a documented standard.
- 03
Decided case by case
Solid hardwood, sealed millwork and contents. Some is salvageable with specialist cleaning and some is not, and the honest answer depends on how long it sat.
Why it happens here
- 01
Roots in the older laterals
The established parts of {{MAIN_AREA}} have clay laterals with jointed sections, and a tree root finds a joint because that is where the moisture is. It grows in as a fine mat, catches solids, and the line narrows over years until one ordinary Tuesday it does not pass. It will happen again if the blockage is cleared and the cause is not. A camera in the line answers that in an afternoon.
- 02
Grease, and the things sold as flushable
Cooking fat goes down warm and sets cold on the pipe wall, and each layer catches the next thing that passes. Wipes sold as flushable clear the toilet and then do not break down, so they gather exactly where the line is already narrowed by grease or a root.
- 03
The storm that arrives in the line before it arrives at the door
Monsoon rain is short and very intense, and the ground sheds it rather than absorbing it. Stormwater gets into sanitary lines through defective joints and manholes, and a municipal line already at capacity has nowhere to put it. When that line surcharges, the pressure looks for relief at the lowest openings connected to it: the ground floor fixtures in the lowest houses on the street. This backup arrives with the storm rather than because of anything anybody in the house did, and people assume it must be a flood claim when it is the water backup endorsement that would have answered.
The part of the policy nobody
reads until it matters
A standard homeowners policy excludes water backing up through sewers or drains. Not limits it, excludes it. The coverage exists, it is added by a water backup endorsement, it is usually one of the least expensive endorsements on a policy, and most households in this valley do not carry it, because it is not automatic and nobody raises it at renewal.
The distinction the policy draws is about direction. A supply line or a water heater failing suddenly is water arriving from the clean side of the plumbing, and that is generally covered. The same volume arriving back up the drain side is a different peril with a different answer.
You can settle this in two minutes on a calm day. Pull up the declarations page and look for a line naming water backup or sewer backup with a limit next to it. If there is no line, there is no coverage. Whether a public agency carries responsibility for a failure in a main is a separate process, and not one to rely on while the house is wet.
In most jurisdictions the lateral from the house to the main belongs to the property owner, so ask your utility where responsibility divides on your street. If backups have happened more than once, a backwater valve is the usual preventive measure.
Read next
-
01
The first hour after a leak
The general protocol, for the losses where the first move is the shut off valve.
-
02
The 48 hour window
What has to be dry, how quickly, and why the dry air outside does not do it for you.
-
03
Why a house nowhere near water takes on water
The other Category 3 water: the kind that arrives across the ground in a storm.
-
04
Questions and answers
Twenty questions about claims, drying, contamination and what any of it depends on.
If a drain has backed up,
keep everybody out of the room
and get a crew moving.
Emergency service across the valley, dispatched 24 hours a day. Independently owned and operated.