Mold Damage & Crawl Spaces in Wisconsin & Illinois

Rotting, decaying crawl space wood damaged over time in Greendale

When mold and rot are allowed to grow in crawl spaces, they lead to health and structural problems that will affect the entire home.

Crawl space mold and rot is a housing epidemic across the United States and Canada that, with a small investment, can be easily avoided.

Installing a crawl space vapor barrier system in your home will protect it from most of the common causes of rot, damage, and humidity. Installation of this kind of system usually takes less than a day to complete.

Free Mold Repair Quotes!

At Badger Basement Systems, we're proud to offer homeowners within our Wisconsin & Illinois service area free, no-obligation crawl space repair quotes.

Each quote includes a professional, on-site inspection of your home, a consultation where we answer any questions you may have, and a written cost quote. To get started on your home repairs, contact us by phone or e-mail today!

What Causes Crawl Space Mold?

Open crawl space vents allowing in humidity and water in Belvidere

Crawl space vents allow humidity, rainwater, and pests into your home.

Mold loves dark spaces, unseasoned lumber, and high humidity levels. Because your crawl space is warmed by your home above it and the natural warmth of the ground below, it stays at about 50 °-60 ° Fahrenheit all year long.

Practically speaking, mold spores are everywhere -- no matter how clean your home is.

To begin growing in your home, mold needs the following:

  • Oxygen
  • A relative humidity level of at least 60%
  • Temperatures at 40°F or higher
  • Organic material to use as food

For rot and mold to grow on wood, the wood needs to have a moisture content of 20-29% or higher.

If your home meets all of these requirements (many do), then you have mold growing in, and damaging, your home.

Mold & Moisture Sources In Your Crawl Space

Even in the case of dry rot, there will need to be a source of water nearby. This water can enter a crawl space through poorly designed downspouts or grading, through groundwater flooding, and/or through plumbing leaks.

Mold can also grow when there's adequate moisture in the air, in the form of humidity. This moisture commonly enters a crawl space as water vapor passing thorough the soil or concrete. In this case, concrete will wick water and through the ground and releases it into the air.

One of the most common and avoidable reasons for crawl space mold and rot, however, are crawl space vents. In the summer, these open vents let in summer air, which is often loaded with humidity. As the air enters the crawl space, it quickly cools in this dark space. As air cools, it loses some of its ability to hold moisture, and the excess moisture is dropped on surfaces in your crawl space as condensation.

Over time, this condensation will saturate the wood in your crawl space--and mold will grow.

Still Believe Crawl Space Vents Work?

Ask yourself these questions:

  1. Are my crawl space vents drying my home when it's rainy, foggy, or damp outside?
  2. If crawl space vents work, why is my vented crawl space damp and rotting?
  3. When cold winter air is blowing through my vents in the winter, what's happening to my furnace, hot air ducts, water heater, and hot water pipes? What is that costing me?
  4. Will my open crawl space vents keep out termites, ants, mice, and other pests?

Signs Of Crawl Space Mold Problems

Extensive crawl space rot damage growing in Richland Center

Surface mold will create cosmetic discoloration only and can be cleaned off without worry.

Decay fungi (above) will darken and shrink the wood while causing structural damage.

Signs of crawl space mold are often evident without having to enter the crawl space at all. Because air moves upwards in a home as it's heated, a vacuum is created that will pull air up through the crawl space through a process known as the "stack effect". If your crawl space has mold, you will be able to tell -- your house will smell musty, and you may even begin to feel and/or display symptoms of mold and dust mite allergies.

Additionally, as crawl spaces begin to rot and decay, the floor above will begin to sag, buckle, or become uneven. Doors may jam, mold may grow on first floor carpeting, and, in the long run, the floor itself will collapse inwards.

In the crawl space itself, warning signs include visible mold growth, musty odors, and discoloration and/or signs of water damage on the wood.

White, powdery substances on concrete walls is not likely to be mold itself, but it's indicative of moisture passing through the walls and creating a humid environment. If there are moldy, musty odors, then mold will be somewhere.

Types Of Mold In Crawl Spaces

Dry rot damage on wood in Watertown

Dry rot damage on wood. Notice the cube-shaped pieces flaking off the wood's surface.

Mold and rot fungi can be classified in two ways: what grows on the surface, and what grows within the wood itself.

Surface mold fungi will cause cosmetic discoloration only, and it will not significantly damage the structural strength of the wood. This mold can simply be cleaned off the surface.

Decay fungi will darken and shrink the wood, leading to severe structural damage of the wood and the eventual crumbling and decomposition of the wood overall. Wood with decay fungi looks soggy and spongy. This cannot simply be cleaned off, and replacement of damaged wood may be necessary.

One other variety of wood-damaging fungi is dry rot, also known as brown rot and cubical rot. As displayed in the photo above, wood damage from this kind of rot is shown as deteriorating the wood into small squares or rectangles. Often mistaken for termite damage because of its appearance, this is an extremely damaging type of fungi.

One other unique feature of dry rot is its ability to pull water from far-away water sources through "rhizomorphs." Rhizomorphs can extend for as much as thirty feet, stretching across brick, concrete, mortar, and similar materials. In the case of Serpula lacrymans, water has been transported as much as three stories upwards!

More About Dry Rot Damage

Preventing & Eliminating Crawl Space Mold

Humidity Warning!

Some major cases of crawl space humidity stem from where your dryer vents end. If your dryer is sending air into your crawl space, it's also sending a ton of humidity with it! This humidity is exactly what mold, rot, and mildew need to start thriving in your home. If your dryer is sending air into your crawl space, fix the problem right away!

Traditional methods of mold removal, such as bleach and water, will not provide a long-term solution for mold removal. These methods do not address rot damage or humidity issues.

Mold will begin growing again in 24-48 hours if the mold-growing environment is not changed. And dormant fungi can reactivate when dry, infected wood becomes wet again.

The solution to crawl space mold and moisture is to seal the crawl space vents, install a plastic liner on the walls and floors, and dry the space with a self-draining dehumidifier. Otherwise, any repairs and mold remediation steps you take are a temporary fix only.

Badger Basement Systems offers free crawl space repair quotes in Wisconsin & Illinois, including Racine, Waukesha, Eau Claire, Janesville, West Allis and many areas nearby. Contact us today to get started!

Looking for a price? Get a no cost, no obligation free estimate.

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Cities in Boone County, IL
Belvidere
Caledonia
Capron
Garden Prairie
Poplar Grove

Cities in Dekalb County, IL
Kirkland

Cities in Mchenry County, IL
Alden
Harvard
Hebron

Cities in Stephenson County, IL
Davis
German Valley
Ridott
Rock City

Cities in Winnebago County, IL
Cherry Valley
Durand
Loves Park
Machesney Park
Pecatonica
Rockford
Rockton
Roscoe
Seward
Shirland
South Beloit
Winnebago

Cities in Adams County, WI
Adams
Arkdale
Friendship

Cities in Barron County, WI
Almena
Barron
Cameron
Chetek
Dallas
Prairie Farm
Turtle Lake

Cities in Buffalo County, WI
Alma
Cochrane
Fountain City
Mondovi
Nelson

Cities in Chippewa County, WI
Bloomer
Boyd
Cadott
Chippewa Falls
Cornell
Holcombe
Jim Falls
New Auburn
Stanley

Cities in Clark County, WI
Chili
Curtiss
Granton
Greenwood
Humbird
Loyal
Neillsville
Owen
Thorp
Willard
Withee

Cities in Columbia County, WI
Arlington
Cambria
Columbus
Doylestown
Fall River
Lodi
Pardeeville
Portage
Poynette
Rio
Wisconsin Dells

Cities in Crawford County, WI
Eastman
Ferryville
Gays Mills
Prairie Du Chien
Soldiers Grove
Steuben
Wauzeka

Cities in Dane County, WI
Belleville
Black Earth
Blue Mounds
Cambridge
Cottage Grove
Cross Plains
Dane
De Forest
Deerfield
Madison
Marshall
Mazomanie
Mc Farland
Middleton
Morrisonville
Mount Horeb
Oregon
Stoughton
Sun Prairie
Verona
Waunakee
Windsor

Cities in Dodge County, WI
Beaver Dam
Horicon
Hustisford
Iron Ridge
Juneau
Lowell
Neosho
Randolph
Reeseville
Rubicon
Watertown

Cities in Dunn County, WI
Boyceville
Colfax
Downing
Eau Galle
Elk Mound
Knapp
Menomonie
Ridgeland
Sand Creek
Wheeler

Cities in Eau Claire County, WI
Altoona
Augusta
Eau Claire
Fairchild
Fall Creek

Cities in Grant County, WI
Bagley
Bloomington
Blue River
Boscobel
Cassville
Cuba City
Dickeyville
Fennimore
Glen Haven
Hazel Green
Lancaster
Livingston
Montfort
Mount Hope
Muscoda
Platteville
Potosi
Stitzer
Woodman

Cities in Green County, WI
Albany
Brodhead
Brooklyn
Browntown
Juda
Monroe
Monticello
New Glarus

Cities in Iowa County, WI
Arena
Avoca
Barneveld
Cobb
Dodgeville
Edmund
Highland
Hollandale
Linden
Mineral Point
Rewey
Ridgeway

Cities in Jackson County, WI
Alma Center
Black River Falls
Hixton
Melrose
Merrillan
Millston
Taylor

Cities in Jefferson County, WI
Fort Atkinson
Helenville
Ixonia
Jefferson
Johnson Creek
Lake Mills
Palmyra
Sullivan
Waterloo
Watertown

Cities in Juneau County, WI
Camp Douglas
Elroy
Hustler
Lyndon Station
Mather
Mauston
Necedah
New Lisbon
Wonewoc

Cities in Kenosha County, WI
Bristol
Kenosha
Pleasant Prairie
Powers Lake
Salem
Silver Lake
Trevor
Twin Lakes
Wilmot

Cities in La Crosse County, WI
Bangor
Holmen
La Crosse
Mindoro
Onalaska
Rockland
West Salem

Cities in Lafayette County, WI
Argyle
Belmont
Benton
Blanchardville
Darlington
Gratiot
Shullsburg
South Wayne
Woodford

Cities in Marquette County, WI
Briggsville

Cities in Milwaukee County, WI
Cudahy
Franklin
Greendale
Hales Corners
Milwaukee
Oak Creek
Saint Francis
South Milwaukee
West Allis

Cities in Monroe County, WI
Cashton
Kendall
Norwalk
Sparta
Tomah
Warrens
Wilton

Cities in Ozaukee County, WI
Cedarburg
Grafton
Mequon
Saukville
Thiensville

Cities in Pepin County, WI
Arkansaw
Durand
Pepin
Stockholm

Cities in Pierce County, WI
El Paso
Elmwood
Maiden Rock
Plum City
Rock Elm
Spring Valley

Cities in Polk County, WI
Amery
Balsam Lake
Clayton
Clear Lake

Cities in Racine County, WI
Burlington
Caledonia
Franksville
Kansasville
Racine
Sturtevant
Union Grove
Waterford

Cities in Richland County, WI
Cazenovia
Gotham
Lone Rock
Richland Center
Viola

Cities in Rock County, WI
Avalon
Beloit
Clinton
Edgerton
Evansville
Footville
Janesville
Milton
Orfordville

Cities in Rusk County, WI
Conrath
Sheldon

Cities in Saint Croix County, WI
Baldwin
Cylon
Deer Park
Emerald
Forest
Glenwood City
Hersey
Wilson
Woodville

Cities in Sauk County, WI
Baraboo
Hillpoint
La Valle
Lake Delton
Loganville
Merrimac
North Freedom
Plain
Prairie Du Sac
Reedsburg
Rock Springs
Sauk City
Spring Green

Cities in Taylor County, WI
Gilman
Lublin

Cities in Trempealeau County, WI
Arcadia
Blair
Dodge
Eleva
Ettrick
Galesville
Independence
Osseo
Strum
Trempealeau
Whitehall

Cities in Vernon County, WI
Chaseburg
Coon Valley
De Soto
Genoa
Hillsboro
La Farge
Ontario
Readstown
Stoddard
Viroqua
Westby

Cities in Walworth County, WI
Darien
Delavan
East Troy
Elkhorn
Fontana
Genoa City
Lake Geneva
Lyons
Pell Lake
Sharon
Walworth
Whitewater
Williams Bay

Cities in Washington County, WI
Colgate
Germantown
Hartford
Hubertus
Jackson
Richfield
Slinger
West Bend

Cities in Waukesha County, WI
Big Bend
Brookfield
Butler
Delafield
Dousman
Eagle
Elm Grove
Hartland
Lannon
Menomonee Falls
Mukwonago
Muskego
Nashotah
New Berlin
North Prairie
Oconomowoc
Okauchee
Pewaukee
Sussex
Wales
Waukesha

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