Skip to Main Content
Stair step crack in basement wall.

Everything to Know About Basement Wall Cracks 

Even though wall cracks are a pretty common occurrence, that doesn’t mean you should ignore them. Wall cracks get worse over time and put your basement at risk – it’s important to understand what causes them so you can stay prepared.

Schedule Free Inspection

Wall cracks are NEVER something to ignore, especially when they’re in your basement. 

Not only does your basement provide additional space for your home, but it also serves as the main foundation – supporting virtually every part of the building such as the floors, ceilings, and walls.  

Understanding what causes basement wall cracks is the first step in preventing them and keeping your home protected.  

Baker’s Waterproofing wants to make sure homeowners in cities like Pittsburgh, Scranton, Harrisburg, and surrounding areas receive helpful information about basement wall cracks. This common problem sign affects thousands of homes every year, so read on to learn more! 

Why Basement Walls Crack

Simply put, basement walls crack because of water accumulation. Since Pittsburgh, and the surrounding areas, tend to receive high amounts of rainfall throughout the year, basement issues are common. 

Hydrostatic Pressure

After rain or snow, water drains into the soil. Some of this water collects next to your basement’s exterior walls. Every time it rains or snows, even more water accumulates near the basement.  

Eventually, this buildup of water causes pressure to rise and push against the basement walls. This is the force called hydrostatic pressure and it’s one of the biggest reasons for basement cracks in our area. 

Expansive Clay Soil

Soil in the Greater Pittsburgh area is around 80% clay. This is a problem for your basement’s walls because clay soil is highly expansive which means the ground swells up when it absorbs water. 

Since soil surrounds your basement on all sides, it’s likely that expansive soil will push against the walls after rain or snow. In our area, rain and snow are common, so this is a big issue. 

Clay Bowl Effect

In the paragraph above, we covered how clay soil expands and pushes against your basement walls. Well, clay soil also causes another issue that puts your walls at even more risk.  

Once all the water has drained from the ground, clay soil becomes dry, which causes it to shrink back down and become brittle. This creates two problems: 

  • Brittle soil does not provide adequate support for your basement walls and makes the entire structure vulnerable to damage.  
  • After the soil shrinks, a gap opens up between the ground and your basement walls. When it rains again, water can build up in the gap and put pressure on basement walls.  

As you can see, clay soil has the capacity to cause multiple problems for your basement. Since this type of soil is so common in our area, it’s important to understand the risks.  

Identifying Basement Wall Cracks

Looking for basement wall cracks is easy because the damage is extremely visible. If you notice any kind of cracking along your basement’s walls, you should always contact someone to inspect them.  

That being said, there are a few specific types of basement wall cracks you can look out for. Below, we’ll outline a few and provide corresponding images so you know what to look for: 

  • Horizontal Cracks – run horizontally along basement walls and indicate exterior pressure 
  • Stair Step Cracks – appear along mortar joints, where individual brick or cement blocks meet 
  • Hairline Cracks – smaller cracks that indicate settling concrete, will get larger if not addressed 
  • Vertical Cracks – run vertically along basement walls, generally caused by foundation settlement 

Remember, if you see any cracks on your basement walls be sure to contact a professional to inspect your home as soon as possible. Even the smallest cracks will get worse over time and pose serious risks.  

The Risks of Ignoring Basement Wall Cracks

Once you see a basement wall crack, do not ignore it. Without any action, the problem gets worse over time and eventually leads to even worse basement problem signs, some of which we’ll go over here. 

Basement Flooding

Water always finds the path of least resistance, so when cracks open up in your basement walls, water begins to seep through them. If ignored, the cracks will only get bigger and allow more water inside. 

Eventually, all of this water will build up in your basement and lead to large puddles, standing water, and flooding throughout the space. No one wants to wade through water below their home. 

Water Damage

Once water gets into your basement through wall cracks, it can cause various types of water damage. Most prominently, mold growth is likely to occur and humidity levels will rise throughout the space.

This can ruin any personal possessions like furniture, important documents, appliances, or decorations found in your basement. Moreover, this may lead to structural issues like wood rot or wet drywall. 

Iron Bacteria

Iron bacteria, also called iron ochre, is most easily identified by its rust colored appearance. This occurs after certain bacteria feed on iron minerals found in soil and water.

This issue can put pipes and appliances found in your basement at risk. If given enough time, iron bacteria builds up on this equipment and corrodes it.  

This can cause clogs and leaking, which only leads to more water in your basement. Fixing wall cracks helps prevent iron bacteria from getting out of control.

Basement Wall Cracks


No, cracks are never normal, but some are more common than others.  

Some cracks arise because of foundation settlement or the concrete curing process. Other cracks are caused by exterior pressure. All cracks should be inspected and repaired as soon as possible. 

The bigger the crack is, the more serious it is. However, all cracks should be taken seriously because even the smallest grow bigger over time – they won’t fix themselves.  

If floor cracks occur in your basement, it’s probably because of foundation settlement and groundwater. For that reason, you should always address floor cracks quickly.  

Call Baker’s for a Free Estimate!

Baker’s Waterproofing, a Groundworks company, is the largest and most reputable foundation repair company in Pennsylvania.  

Since 1975, our team has been helping homeowners across the state repair and protect their foundations and concrete.  

We value our customers’ safety first and foremost, and we hope this information has helped you feel more prepared and educated about potential basement issues.  

If you’ve seen wall cracks below your home, or you want to prevent them all together, contact us today for a free estimate and inspection! 

We’re proud to serve the following areas: 

  • Pittsburgh 
  • Harrisburg 
  • Johnstown 
  • Lancaster 
  • Lehigh Valley 
  • Morgantown, WV 
  • Scranton 
  • State College 
  • York 

Don’t See Your Area? Check Here

Publish Date:

Last Modified Date:

Baker's Waterproofing Service Areas

Our Locations

Central PA

3819 N Susquehanna Trail
Shamokin Dam, PA  17876


922 North 3rd Street
Harrisburg, PA 17102


701 North Hermitage Rd, Suite 25,
Hermitage, PA 16148


5 Industrial Road, Building B
Washington, PA 15301

Wilkins Township

201 Penn Center Blvd Suite 400

Wilkins Township, PA 15235

York, PA

800 E King St, Suite 518
York, PA 17402