Need a Basement Inspection? Here’s What Pros Check For

Scott Dylan Westerlund
Updated November 1, 2022
New family room in the basement
Photo: alabn / iStock / Getty Images Plus

Your basement can be out of sight, but not out of mind

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Whether you spend time in your basement for work, pleasure, or to occasionally reset the circuit box, a basement inspection is a practical way to get ahead of any issues lurking down below. Similar to a home inspection, but focused on your lower level, basement inspections can clue you into structural breaches, moisture and mold, pests, and other unwelcome trouble. A qualified contractor can spot any problems and boil them down for you. Here are tips on what to expect from a basement inspection.

Basement Problems to Watch For

There are a few signs of trouble you should know to spot on your own. Water that seeps into the basement due to poor waterproofing can cause cracks. Cracks are prioritized during basement inspections because they threaten your foundation's structural integrity. Your inspector will also examine several key systems in your home prone to moisture and leaks.

You should also keep your ears—and nose—open for any strange odors, or noises coming from large appliances. If your basement has windows, look out for any broken glass panes.

1. Cracks in Your Walls or Foundation

Cracks usually form along your home's joints. However, contractors should review every possible crack location to avoid overlooking dangers.

A pro will be able to suggest remediation options for waterproofing your basement against cracks. However, a serious crack in your foundation may require you to consult a structural engineer.

Here are the specific crack types your contractor will look for in your basement.

  1. Horizontal cracks: Stress and pressure on your home's foundation caused by rainwater and groundwater are usually responsible for horizontal cracks.

  2. Vertical cracks: If a builder cut corners with low-quality materials when constructing your home, moisture seepage may cause vertical cracks.

  3. Diagonal Cracks: Disasters happen when pressure from rainwater and groundwater sources causes uneven settling.

  4. Stair-Step cracks: These unique cracks form down your home's mortar lines due to pressure from rainwater and groundwater if you have a home built using mortar.

2. Your Sump Pump

Sump pump installed in a home basement
Photo: IcemanJ / Adobe Stock

If your home has a sump pump, your basement contractor will surely take a look at it. Sump pumps keep groundwater from leaking into your basement, which can cause structural damage as well as humidity, mold, and foul odors. Signs of clogs in the inlet screen or discharge line or indicators that your sump pump’s motor is not working will trigger your inspector to dig deeper and search for additional leaks or signs of flooding.  

3. Plumbing System and Water Damage

Basement contractors will look at plumbing pipes to detect potential leak sources. Exposed pipes lead to dampness and moisture. Eventually, pipes will rust, degrade, and drip in places they shouldn’t. Some obvious signs of a basement leak include:

  • Basement temperature dips

  • Foggy basement windows

  • Sticking doors

  • Warming items

  • Mold

  • Odors

If a contractor comes back with a report that your basement is showing signs of a leak, you may want to consult a second professional for a full basement inspection. It's a good idea to use a professional service that utilizes engineers when diagnosing basement issues to ensure that the problem can be covered from a structural angle.

Pipes don't always tell the full story. Here's a list of the obvious signs of a basement leak.

Basement Temperature Dips

Don't ignore a nip in your basement’s air. A chilly basement reveals a potential leak source. When the basement temperature dips, this is a sign of water seeping through the foundation. Water entering a basement through a leak source will increase moisture levels to create higher-than-normal ambient air temperature.

Foggy Basement Windows

Like chillier ambient air temperature, foggy basement windows also point to excessive moisture. Windows don't actually cause condensation. However, they can provide the most obvious visual indicator that moisture has moved in. Condensation forms on windows when warm, humid air interacts with a cold surface. This is why condensation often appears on days when the outdoor temperature drops.

Sticking Doors

A sticking door isn't usually a "door" problem, but rather a moisture problem. Sticking doors indicate that wooden frames around your doors are expanding due to moisture. The obvious reason for a sticking door in the basement is that basement air has grown damp.

Warming Items

If there's a general feeling of damp warmth when you touch items in your basement, this is a sign of a leak. Rainwater and groundwater can create a humid environment that leaves furniture, electronics, and other objects stored in your basement feeling unsettlingly warm to the touch.


In an ideal world, mold would be detected before it can spread throughout a home. Mold can be a sign of previous, current, and recurring leaks in a basement. If mold is detected, homeowners need to come up with a plan to address mold from several angles.

The first task is identifying the source of the mold. The second is to remediate any mold damage by cleaning mold-infected areas, throwing away items that cannot be salvaged, and properly airing out the space. Lastly, a plan for preventing future mold growth by cutting off the moisture source must be created.


A musty smell is the signature scent of a basement leak. You may also notice that objects that are taken from the basement carry a strong odor. People who are allergic to mold, mildew, and allergens may have strong physical reactions that range from sneezing to headaches when entering an odorous basement. 

Rotten Wood

Warmed, rotted trim around basement doors and windows signals leakage. In many cases, trim needs to be removed in order for a professional to conduct a full inspection.

Peeling Paint

Chipping and peeling on the walls may indicate a leak. Typically, these are signs of an older leak. Wallpaper that pulls away from a wall can mean that adhesive was soaked at one point. Chipping paint occurs after wet walls have dried.

Weak Caulking

Peeling or disintegrating caulk can indicate excess moisture. This is more likely if the caulking job is damaged even though it's relatively fresh.

Sagging Drywall

Sagging drywall is a sign of severe water leakage in a basement. While it's rare for drywall sagging to occur unless a homeowner has ignored other obvious signs of leakage in a basement, it's possible for sagging to grow extreme if a homeowner is not regularly entering the basement to check for signs of water damage.

4. Your Insulation

 Large unfinished basement with wall insulation
Photo: Jason / Adobe Stock

Did you know that your home's insulation helps create a barrier between the dry interior of your basement and the soil outside? Insulation failing to provide waterproofing support actually creates the perfect environment for dangerous mold to form. Wet insulation can even attract rodents from the outside who will chew through insulation and render it much less effective. 

Signs that it’s time to replace your basement insulation include holes, rodent droppings, mold, and moisture. You may get the word from a local inspector that it's time to replace your insulation if your current insulation fails to insulate properly or creates a health hazard in your home.

5. Pest Damage

Inspectors will look for signs of pest infiltrations. The moist environment of basements attracts crickets, millipedes, pill bugs, sow bugs, and termites. In addition, a combination of easy access and inviting warmth can make basements appealing to mice and rats. When tracking down pests, inspectors will look for droppings, greasy rub marks, dead bugs, dead rodents, nests, and damaged items.

6. Basement Appliances

Ideally, a savvy basement inspector will also examine any large appliances in your basement. They can check out anything from your washer and dryer to an auxiliary freezer. Generally, an inspector will check for any fire hazards caused by improper connections or placement.

7. Home Exterior

What happens outside the walls of your basement can affect the health and safety of your basement. During a basement inspection, a professional will do a perimeter check to ensure that soil isn't touching wood framing or siding. Having a clearance of several inches is necessary to prevent water damage, rot, and insect entry.

In addition, soil placement that allows for water to slope toward the house following rainstorms can create flooding conditions in a basement.

A basement inspector also looks for corner cracks and bowing that indicate movement of the basement wall. Repairing a basement block wall can be done by using hydraulic cement, carbon fiber straps, epoxy crack injections, or wall beams as reinforcement materials.

Exterior veneer is also checked for signs of movement. Cracking, shifting, or bowing veneer indicates movement of a home's foundation.

Lastly, a basement inspector will look for any cracks in the home's foundation. Cracks are entry points for moisture that can ultimately compromise the foundational integrity of a home.

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