You may notice a variety of foundation damage symptoms throughout your home, depending on what is causing the issue and how severe it is. We’ll go over the typical signs of an under-home issue below and discuss the most likely trigger of each.
Foundation Cracks
Foundation cracks are typically the easiest form of damage to spot, but they don’t always mean you have a severe problem. The gap’s location, orientation, and width can help determine how dangerous it is.
Basement Floor Cracks
Gaps that develop on your crawlspace or basement floor that remain thin and level across the fissure are attributed most often to natural concrete settling. You may also be able to identify these on a slab foundation if your concrete is exposed for any reason.
Your foundation adjusts to the ground underneath and the weight of your house above after construction, and thin cracks in the floor typically occur during that period.
They aren’t usually a sign of structural damage, so the best option is to have them sealed with epoxy or polyurethane to reduce the risk of water or moisture entering your house through them.
If the cracks widen beyond ⅛”, continue to grow after the first few years following construction, or are uneven from side to side, they’re likely due to differential settling. In these cases, your foundation may need structural repair to avoid significant damage and foundation failure.
Vertical Wall Cracks
Cracks that develop on your concrete block wall or the outside of your slab that run in a vertical direction are also usually from settling.
These gaps should always be sealed to keep water out. If the crack widens to beyond ⅛”, it’s best to consult a structural engineer or foundation repair expert with years of experience to inspect the gap and make sure there isn’t a severe problem.
Horizontal Wall Cracks
Fissures on your crawlspace or basement wall that run laterally to the ground are significantly more hazardous. They’re a result of excess hydrostatic pressure from outside that has forced your wall inward to the point where it cracked.
This can occur if underground erosion leaves voids against your concrete, as the water that fills them is much heavier than the soil and can compromise the walls’ structural integrity.
Generally, these cracks require extensive and costly stabilization before they are sealed.
Stair-Step Wall Cracks
Cracks can also develop in a step pattern between the concrete blocks of your foundation wall. This type of damage is common in Minneapolis because differential settling from underground erosion can leave portions of your concrete without support.
The area that loses support sinks further into the earth, eventually cracking away from the rest of your home.
Stair-step cracks typically indicate structural problems and necessitate the most costly repairs. Neglecting to correct this problem could lead to structure collapse over time.
Bowing Foundation Wall
When hydrostatic pressure from the soil around your home pushes your foundation walls inward, the concrete eventually cracks from the added stress. However, your foundation wall can flex slightly before a fissure forms.
As such, you may notice inwardly bowing walls in your crawlspace or basement. This is often caused by water accumulation in voids against your concrete, and it typically precedes the formation of a horizontal crack.
Water Damage or Moisture Build-Up
Liquid water and water vapor both pose serious problems for foundations in many areas. Unfortunately, the soil and climate in Minneapolis make these very prevalent issues.
Water typically enters your foundation through cracks, so you may notice water trickling in through gaps in the concrete. You might also find water pooling on the floor, water stains on the walls or floor of your under-home area, standing water, or wet spots on the concrete. These symptoms will generally be most apparent following rainfall.

Water vapor isn’t visible, as it seeps through pores in the foundation and evaporates in the air. However, the accumulation of moisture under your house typically leaves behind identifiable symptoms.
These include efflorescence on the foundation walls, mold growth, musty or moldy smells, and damp air. Insects or rodents living under your home can also indicate moisture presence, as they are attracted to humidity.
Poor Indoor Air Quality
Lastly, water and moisture problems under your home can decrease the air quality in your living space, as moisture and mold spores can seep up into your house from underneath.
You may notice uncomfortably hot or cold temperatures in your living space from the moisture in the air or utility bills that are higher than usual because of the greater demand for heat or cooling. Mold spores coming into your living area can cause allergic reactions, so unexplainable sneezing, itchy eyes, or respiratory distress can all indicate a water-related mold issue.
These symptoms are particularly useful for detecting a moisture problem if you have a slab foundation, as you won’t have access to the space under your house to look for more obvious signs of water intrusion or moisture accumulation.