Oregon flooded basement cleanuppumped, cleaned and dried out

Groundwater is the most common source in the wet season. After weeks of rain the soil around a foundation is saturated, and water presses against the basement walls and floor. It finds the cracks, the joint where the wall meets the floor, old tie holes and the gaps around pipes. This is why many western Oregon basements stay dry all summer and then take on water in January.

Surface water is the second. Clogged gutters, short downspouts and yards that slope toward the house dump roof and lawn water right against the foundation. Window wells fill like buckets and overflow through the window. A driveway that slopes down to a basement garage door can channel a lot of water inside.

Plumbing is the third. Water heaters, washing machines and supply lines in basements fail just like they do upstairs, but the water has nowhere to go. A failed water heater can empty its whole tank onto the floor and keep refilling until someone shuts it off.

Sewer backups are the fourth. When the public sewer or a home's own line is overwhelmed or blocked, water comes up through the lowest drain, which is usually in the basement. That water is contaminated and handled differently; see sewage backup cleanup.

Western Oregon's rainfall is concentrated in the cool season. Portland's airport averages close to 37 inches a year, with November, December and January the wettest months and about 157 days a year with measurable rain. ^[1] Salem and Eugene each average around 40 inches. Rain that falls steadily for weeks keeps the soil wet down to foundation depth, and water tables can rise.

Atmospheric rivers are what turn a wet winter into a flood. These long, narrow bands of moisture, sometimes called the Pineapple Express when they come from near Hawaii, can drop several inches of rain in a day or two. The 1964 Christmas flood and the February 1996 flood were both driven by warm, heavy rain on top of snow and frozen or saturated ground. ^[5] In 1996 the Willamette crested at 28.6 feet in Portland, about 10.6 feet above flood stage, and downtown Oregon City was underwater for days.

Most basement water in Oregon is not river flooding, though. It is groundwater and surface water during long wet spells, plus the occasional failed sump or water heater. River and creek flooding does affect some neighbourhoods, along Johnson Creek in southeast Portland, the Tualatin River in Washington County or Bear Creek in the Rogue Valley, and those homeowners should know their flood zone.

A small amount of clean water on an unfinished concrete floor, from a water heater drip or a minor seep, is often something you can handle. Mop or shop-vac it up, run a dehumidifier for a few days and keep an eye on the walls.

The job moves beyond DIY when the basement is finished, when water has soaked into carpet, framing or insulation, when it covered more than a small area or when the source was outside water or a drain. Removing wet finishes, drying concrete behind framing and confirming that everything reached normal readings takes equipment and meters most homeowners do not own.

The EPA notes that significant water damage and anything involving sewage should be handled by experienced professionals, and recommends a respirator, gloves and goggles for mold cleanup. Basements combine all of those risks.

Basements are most common in Portland's older neighbourhoods, where many early twentieth-century houses have full or partial basements, and in some hillside areas around the metro. Many of these basements were built as storage and utility space and later finished. That is where seepage problems most often turn into major cleanups.

In the Willamette Valley outside Portland, crawlspaces are more common than basements, but basements exist in older parts of Salem, Eugene and Albany and in many custom homes. Wherever they are, the same wet-season pattern applies.

Portland's sewer system includes older combined sewers in parts of the city, where storm and sanitary flows share pipes. The city's Big Pipe tunnels were built to cut combined sewer overflows to the rivers. ^[7] For a homeowner, the practical point is that a basement floor drain is the lowest outlet in the house, and if water comes up through it during heavy rain, call it in to the city's Environmental Services as well as getting it cleaned up.

Central Oregon basements see less groundwater seepage, but frozen pipes and snowmelt against the foundation cause their share of basement water.

This is where many homeowners are surprised. Standard homeowners policies commonly cover sudden plumbing failures, like a burst water heater, but commonly exclude flooding from outside and groundwater seepage. Sewer backup coverage is often an add-on endorsement. Flood insurance is usually a separate policy, often through the National Flood Insurance Program.

Exactly what applies depends on your policy, so check before you need to, and ask your agent about sewer backup and flood coverage if you have a basement. The Oregon Division of Financial Regulation can help with questions about how an insurer is handling a claim.

For more on claims, see our guide to working with your insurance adjuster.

Basement water often goes hand in hand with mold, because basements are cool, dark and slow to dry. If water sat for more than a day or two, see mold prevention after water damage. If the source was a drain or toilet, sewage backup cleanup applies. For the drying stage, see structural drying.

Not sure how the water is classified? Our guide to water damage categories explained covers clean, grey and black water.

Basements are where families keep the things they do not use every day: holiday boxes, old photographs, tools, spare furniture and papers. When water comes in, those things are often the first to be ruined and the hardest to replace.

A useful rule is to sort by material and by water type. Hard plastic, metal and glass can usually be cleaned and kept, even after contaminated water, if they are washed and disinfected. Wooden furniture may survive clean water if it is dried slowly. Upholstered furniture, mattresses, stuffed toys and cardboard boxes that sat in groundwater or sewage are generally not worth keeping.

Paper and photographs are a special case. Important documents and irreplaceable photos can sometimes be saved if they are kept from drying stuck together; some people freeze wet papers until they can be dealt with properly, and specialist document restorers exist. Ask the contractor whether they offer contents work or can point you to someone who does.

Whatever you throw away, photograph it first and make a list. Your insurer may want it, and it is much harder to remember afterwards.

Concrete looks solid, but it is porous and holds a surprising amount of water. A basement slab or wall that was under water, or soaked by weeks of seepage, gives that water up slowly, and the cool temperatures in most basements slow it further.

That is why contractors measure the concrete rather than judging by appearance, and why they are cautious about putting new flooring, carpet or framing back against it too soon. Trapping moisture under new finishes leads straight back to musty smells and mold.

In practice, the walls and slab are dried with dehumidifiers and air movers until readings level off, and the rebuild may use materials that tolerate occasional moisture better, such as inorganic insulation or flooring designed for below-grade spaces. The contractor can explain the options for your basement.

A sump pump sits in a pit at the lowest point of the basement floor. Drain tile around the foundation or under the slab carries groundwater to the pit, and when the water rises, a float switch turns the pump on and pushes the water out through a discharge pipe away from the house.

Most sump failures happen for simple reasons: the power goes out during the same storm that brings the water, the float switch sticks, the pump wears out after years of service or the discharge line freezes or clogs. Testing the pump before the rainy season by pouring water into the pit, keeping the pit free of debris and adding a battery backup address the most common ones.

If your basement flooded because the sump failed, tell the contractor. It changes the cleanup only a little, but it matters a lot for what to fix before next winter.

Window wells are a common entry point in Oregon basements. A well is essentially an open pit beside the foundation, and if its drain is clogged or it has no drain at all, it fills with rain during heavy storms until water reaches the window and pours or seeps inside. Leaves and debris make this worse every fall.

Clearing the gravel and debris at the bottom of each well, checking that its drain flows and fitting clear covers that keep rain out while letting light in are simple fixes. Egress windows added during basement finishing deserve the same attention, because their larger wells collect more water.

If water came in through a window during a storm, mention it to the contractor so the wall below the window, often the wettest area, is checked and dried.