Old Marsh, Damp Basements: Moisture Pests Under West Lawn's Brick Homes

A twin suburb that waited 60 years for its houses

Real estate promoters James Webb and John F. Eberhart laid out West Lawn and its eastern twin, Chicago Lawn, in 1877, and Chicago annexed the area in 1889. Chicago Lawn filled in. West Lawn, on lower and wetter land west of the Grand Trunk tracks, mostly did not. Scattered homes appeared in the 1920s, and by 1930 the blocks east of Pulaski and north of 63rd held about 8,900 people, many of them German, Irish, Polish, Czech and Italian families. The Depression stalled building, and the population had reached only about 10,300 by 1940.

The real build-out came after World War II. The Chicago Housing Authority put up housing for returning veterans in 1946, new streets pushed west and south, and builders covered the remaining marsh with brick Georgians, raised ranches and more bungalows. Population climbed to about 14,500 by 1950 and kept rising. Later decades brought many Mexican-American families alongside the Polish and Irish households, and today the community holds about 32,000 residents in roughly three square miles.

That late start leaves two building generations with different weak points. The 1920s and 1930s bungalows east of Pulaski have older block or poured foundations with settled mortar, drain tile that may be clogged or collapsed, and original floor drains tied into the sewer. The postwar Georgians and raised ranches have sounder foundations but often sit low relative to the street, with below-grade entrances and walk-out stairwells that collect water. And both share one thing: the soil was wet before anyone built on it, and in many places it still behaves that way.

Why the lower level is where the trouble lives

Ask local providers what they treat most here and the answer keeps coming back to the basement. Nearly every home has a full lower level, many finished as family rooms, guest space or apartments for relatives, and many sit in soil that holds water. Oriental cockroaches, house centipedes, millipedes, silverfish and camel crickets all need high humidity, and they find it in block walls that wick moisture, floor drains whose traps have dried out and window wells that fill with leaves. None of them damages the house, but large numbers make a finished basement miserable.

Oriental cockroaches are the clearest example. They are large, nearly black, slow and flightless in practice, and they prefer cool, damp spaces to warm kitchens. In these homes they come up through floor drains, out of sump pits and along the cold joint where the slab meets the wall. Sightings climb as basements warm in May and taper by late summer. A pro will usually treat drains and the wall-floor joint with residual products or gel bait, and recommend drain covers or simply refilling traps with water.

Centipedes and millipedes behave differently. House centipedes are fast predators with long, banded legs, so their numbers mirror the silverfish, spiders and crickets they hunt in the basement. Millipedes wander in from mulch beds and wet soil outside, often in waves after heavy rain in late summer and fall, curl up when disturbed and die quickly in dry indoor air. In both cases, drying out the space is what ends the problem.

Combined sewers, summer downpours and what a backup leaves behind

Like most of the city, West Lawn is served by a combined sewer system that carries storm water and household waste in the same pipes. During intense summer storms, those pipes can surcharge and push water back up through basement floor drains, especially in older homes without backflow protection. A backup does more than ruin carpet. It leaves organic debris in drains and on the floor, soaks paneling and cardboard, and raises humidity for weeks, which is exactly what silverfish, springtails, drain flies and oriental cockroaches need to multiply.

After any water event, the pest-smart response is fast drying. Run fans and a dehumidifier, pull out soaked cardboard and wet carpet pad, open up paneling that stayed damp, and clean and disinfect the floor drain. Ask a plumber about a backflow valve or overhead sewer conversion for the long term. Homeowners who handle the drying in the first few days usually avoid the surge of insects that otherwise shows up two or three weeks after a storm.

German cockroaches when two kitchens share one house

Many homes here hold more than one household, with grandparents, adult children or tenants living in a basement unit with its own kitchen. Two kitchens under one roof double the places German cockroaches can settle. These are the pale, half-inch roaches with two dark bars behind the head, and they cluster near heat, food and water: behind refrigerators, in dishwasher frames, under sinks and inside cabinet hinges. They usually arrive in cardboard boxes, grocery bags, used appliances and secondhand furniture.

A single egg case carries dozens of young, so a few roaches on a carton can become a kitchen-wide population by midsummer. Foggers and over-the-counter sprays tend to push them deeper into walls. Providers work with gel baits placed where roaches rest, a growth regulator that stops young from maturing into breeders, and sticky monitors that show whether numbers are really falling. With a basement unit, both kitchens and the plumbing chase that connects them must be treated in the same round.

Fall mice, spring ants and the occasional termite

House mice are the other steady call, especially in the bungalows east of Pulaski and on blocks nearer the Midway area and the rail tracks. They enter at gaps around gas and water lines, under worn garage door seals and along basement window frames, then nest in finished ceilings and behind appliances. Activity jumps in October and November. Trapping alone rarely ends it; the entry points have to be found and sealed with copper mesh, steel wool and mortar.

Pavement ants and odorous house ants trail into kitchens in spring, the first along slab cracks and the second after rain floods their outdoor nests. Eastern subterranean termites live in Cook County soil here too. In a brick home, they usually reach wood through porch steps, wood-framed rear additions or lumber and debris left against the foundation. Mud tubes on a basement wall or a swarm of winged insects near a window in April or May is a reason to call for an inspection.

Norway rats are less of a headline here than in communities along the canal, but blocks backing onto the Grand Trunk tracks on the east and the busy Cicero corridor on the west do see burrows under alley garages, especially where slabs have cracked and carts sit open. Locked bait stations along the garage, packed burrows and a 311 request for alley baiting usually bring a problem down within a few weeks.

Bungalow, Georgian, raised ranch: a below-grade guide

Each main house type here has a basement with its own weak points, and knowing which one you live in helps when describing a problem. Many homes have also been altered over the decades, with enclosed rear porches, added basement bathrooms and rec rooms paneled over bare block. Each change can hide moisture or create a new gap where plumbing was run, so mention any additions when you call.

• 1920s and 1930s bungalows: settled mortar around basement windows, original floor drains, the void under the front stoop
• Postwar brick Georgians: below-grade walk-out stairwells and their drains, the joint where a rear addition meets the main wall
• Raised ranches: the half-buried lower level where brick meets slab, often paneled over damp block
• Homes with basement apartments: two kitchens, a shared plumbing chase and extra laundry moisture
• All types: sump pits without tight lids, dryer vents, A/C line sets and the gas meter penetration

A year in a West Lawn basement

Early spring wakes the basement roaches and sends the first ant lines across kitchen floors. Late spring is the high point for oriental cockroaches and for termite swarms on warm afternoons. The muggy weeks of June and July bring centipedes and silverfish out in force, and July and August storms can push water into basements and drive millipedes in from saturated soil. September and October bring the fall mouse season and another round of millipedes. Kitchen roaches ignore the calendar entirely, and many households notice them most in January, when windows stay shut and two stoves run every evening.

Two local factors bend that pattern. A wet spring raises the water table under the old marsh, and basements that were dry the year before can turn damp enough by June to draw centipedes and springtails. And the first hard cold snap of fall, usually in late October, is the week mice show up in bungalow basements that were quiet all summer, so October sealing beats November trapping.

Drying out the house: a prevention list

Because so many local pests depend on moisture, the most effective prevention here is about water. Treatments help, but they will not hold in a basement that stays damp all summer. Start with the cheapest steps, such as refilling drain traps and extending downspouts, and judge the results over a few weeks before spending on bigger fixes like drain tile repair or regrading. If water shows up on the floor after every storm, a waterproofing contractor or plumber may do more for the insect count than any pest treatment.

• Run a dehumidifier in the basement from May through September, aiming for about 50 percent humidity
• Pour water into unused floor drains monthly, or fit drain covers
• Put a tight lid on the sump pit
• Clear leaves from window wells and fit well covers
• Extend downspouts several feet from the foundation
• Keep mulch thin and pulled back from the brick
• Check boxes and used appliances before bringing them into either kitchen
• Seal utility penetrations and replace garage door seals before October

What a visit looks like in a multi-household home

A provider working in a home with a basement apartment will ask for access to both kitchens and both bathrooms, and will want to know whether anyone is pregnant, elderly or has respiratory issues so products and methods can be chosen carefully. For cockroaches, cabinets usually need to be emptied before treatment. For moisture pests, expect the inspection to cover drains, the sump, window wells and grading outside, with suggestions that may sound more like plumbing advice than pest control. Plan on a return visit after a few weeks to read the monitors and retreat hot spots. A cockroach clean-out is usually scheduled around kitchen prep, but an inspection can often happen the same day.

For mouse work, the visit runs from the garage and gangway to the basement and attic, with sealing done before traps go down. For termites, the inspector will focus on porches, rear additions and any wood touching soil, then explain whether activity is current. Follow-ups are normal for every one of these jobs, so ask how many are included and what each will check.