Common Slab Foundation Repair Problems & How to Solve Them

There are so many reasons why your slab foundation might need repairs. In this article, we’ll talk about common slab foundation problems homeowners have and some foundation repair solutions for these problems.

Problem No. 1: Slab Foundation Settlement

Foundation Settlement is another way to say that the foundation, or parts of it, is slowly sinking into the ground. Settlement can be divided into two main categories.

  1. Uniform settlement
  2. Differential settlement
A crack radiating from a window frame

Uniform settlement is by far the less harmful. This is when the entire foundation settles roughly the same amount. Small amounts of uniform, or roughly uniform, settlement generally isn’t a significant issue. It might cause some minor hairline cracking that might need to be repaired if it leads to water intrusion. Generally, however, it does not cause structural issues.

Differential settlement, however, occurs when a portion of the slab settles more than the rest. As you might expect, this can cause a host of problems.

Issues Caused By Differential Settlement

  • Wall Cracks: If a portion of the foundation isn’t being properly supported by the soil below, it places some of the walls under a level of tensile or compressive force that is sometimes more than the wall can withstand, leading to cracking. This can affect both interior and exterior walls, with stair-step cracks common in exterior masonry walls. Some vertical cracks wider than a hairline can also appear. Often they are wider on one end than the other depending on which section of the house is settling.
  • Slab Cracks: The same forces being applied to the walls are also being applied to the slab floor. This can cause cracking, sometimes including an elevation change on either side of the crack. This of course can lead to another problem.
  • Water Intrusion: Slab cracks offer an avenue for water to make its way into your home, particularly if you have poor drainage around your foundation.
  • Sticking Doors and Windows: Differential settlement can shift the whole home out of alignment. Outside of leading to cracks, this also causes problems for doors and windows. The door or window likely will no longer fit the opening correctly. Some places might stick while others have gaps.
  • Tilting Chimneys: If your chimney is on the outside wall of the house, the settlement could cause it to start tilting and pulling away from the house.
  • Slanting Floors: If your floors suddenly start tilting in one direction, differential settlement might be to blame.

Problem No. 2: Foundation Heaving

While heaving is technically the opposite of settlement, it can cause many of the same problems. This is because it has the same result, the building’s foundation being thrown out of alignment.

Generally heaving is related to “active” clay soils. These soils have extreme shrink-swell cycles. If the clay soil wasn’t properly accounted for during the building process, you could have a cycle of heaving and settlement depending upon the weather and soil conditions.

Frost heaving can also produce similar results.

Problem No. 3: Slab Foundation Construction Defects

If the building’s foundation slab was improperly poured or inadequately supported, it will lead to problems.

This is the only real man-made problem on the list. If the slab isn’t able to support the weight of the home, there are inevitably going to be issues.

Solutions for Slab Foundation Problems

Generally the most common cause of slab foundation problems is settlement. To solve settlement-related issues, you need to accomplish two things:

  1. Lift the foundation back to level
  2. Prevent additional settlement
ECP resistance piers raising foundation

To accomplish this, in most cases we use a foundation underpinning system. Underpinning involves sinking piers into the soil before hydraulically lifting the house back to level and transferring the load to them.

We use steel helical piers and push piers in our underpinning projects. Steel provides the strength needed to support the weight of the house while being able to be sunk deep enough to reach a layer of soil or bedrock strong enough to support the house. Many of the foundation repair methods using concrete can’t say the same thing.

Helical piers are steel bars with helical plates attached to give it the look of a giant screw. Push piers are an end-bearing pier without the helical plates which is sunk into the soil rather than screwed.

We can also repair any cracks that have been caused by the foundation problems.

Need to Repair a Slab Foundation in Southern California? Call us Today.

If you are looking for a professional foundation repair company don’t look any further! Here at Foundations on the Level, we strongly believe in quality customer service and treat every home as if it was our own. Our specialists will work directly with you to analyze the unique problems that your home is facing and come up with the best solution for your needs and budget. We have established a fantastic reputation within Orange County & San Diego County for foundation repair, slab releveling, retaining walls, and more. Contact us for a free estimate!

Do You Know the Signs of Foundation Settlement? (Video)

Do you know the signs of foundation problems related to settlement? Knowing the signs can save you money in the long run. Foundation repairs are much less expensive than foundation replacement. Sticking doors or windows, drywall cracks, interior or exterior cracks in the foundation, countertops pulling away from the wall or your chimney pulling away from the home are all indicators of foundation settlement and could be a serious issue.


If you are a homeowner with any of these issues contact Foundations on the Level for a free estimate today. 

Read more – Article: Solutions for Foundation Settlement

Understanding Foundation Cracks and Knowing When to Repair Them

understanding foundation cracks

The best way to know how to repair foundation cracks is to understand why they happened in the first place. In this post we’re outlining the different types of cracks, how they form, and letting you know when they need to be repaired. In some cases, cracks in your foundation aren’t always a cause for concern.

Types of Foundation Cracks

Hairline Cracks

These nonstructural foundation cracks are generally vertical, and aren’t a cause for concern. These cracks include settlement cracks and shrinkage cracks. They are generally less than 1/32″ in width.

Especially in new construction homes, some cracking from settling is normal, and to be expected. More serious settlement can cause larger cracks, but so long as the cracks remain hairline, they aren’t a cause for concern.

Shrinkage cracks appear within the first few years of the home being built due to stress caused by the concrete shrinking as it dries. These are common and aren’t structural in nature. On their own, shrinkage cracks aren’t a cause for concern.

Vertical Cracks

These types of cracks run straight up and down, or within 30 degrees of vertical. Vertical cracks in walls usually appear due to concrete shrinkage if you have a newer home.

Even if your home isn’t new construction and vertical cracks appear, they are not usually a structural issue. However, over time, this type of crack will allow for water and insects to easily enter your home.

You will want to watch for any moisture, or a rusty looking discoloration in or near the crack. To repair a vertical crack, or make it water-tight, we will use a high-density polyurethane foam to fill in any gaps and voids within the concrete. In some cases, we will use other waterproofing methods throughout the rest of the basement if needed.

Diagonal Cracks

Diagonal cracks are often caused by differential settling of the foundation. Differential settling can happen at any time, whether the house is new or old. This type of settling is caused by a change in the ground conditions underneath the footings, which is why one end of the crack will generally be larger than the other.

They are often harmless, but not always. The most troublesome type of diagonal crack isn’t really a diagonal crack at all. Stair-step cracks in brick or concrete block foundation walls can indicate serious structural issues.

If it is just a hairline, and it doesn’t grow, it probably isn’t structural. Larger stair-step cracks, however, should be looked at by a foundation repair professional, as should other diagonal cracks that are growing or change direction.

Diagonal cracks, assuming they are not structural in nature, can be repaired using the same method we mentioned earlier. However, with diagonal cracks, more foam is typically needed to account for additional future movement.

Horizontal Cracks

A horizontal crack in the foundation is a structural concern. Horizontal cracks are a sign that your foundation might be failing.

Sometimes this is because the damaged foundation can no longer withstand the pressure and weight of the structure. These cracks will appear on load-bearing foundation walls, and develop below grade.

Other times, horizontal cracks in a below-grade foundation wall could be caused by hydrostatic pressure from water-logged soil pressing inward on the wall. If the pressure becomes more than the wall can bear, it will begin to bow inward and crack horizontally.

Tip: Monitor Your Foundation Cracks

If you notice new cracks in your foundation, especially if your home isn’t new, don’t simply write them off as unimportant and forget about them.

Instead, monitor them monthly for growth.

A growing hairline crack, at minimum, might eventually need to be filled to prevent water infiltration.

Also, while vertical and diagonal cracks generally aren’t big deals structurally, there are exceptions (like if you have multiple horizontal cracks in a small area). Monitoring the length and width of these cracks can give you a better idea on if the cracking is minor or if there is an on-going issue causing the damage.

Fixing Structural Foundation Cracks

If you have horizontal or stair-step cracks, you will eventually need to fix to them the same way as the vertical or diagonal cracks.

It does no good, however, to seal them when the underlying problem isn’t fixed. The cracks will just open up again, and other problems caused by the structural issues will only continue to grow.

If unstable soil beneath your home is the culprit, you might need foundation underpinning, where a professional foundation contractor installs a piering system that extends down to a load-bearing strata of soil.

If hydrostatic pressure is making your foundation wall bow, helical tiebacks or plate anchors might be in order, anchoring the wall in the soil outside to provide a counteracting force.

These repairs won’t fix the cracks. That requires an epoxy or foam injection or some other true crack repair method. These fixes will, however, remove the stresses that were causing the cracks to grow in the first place, allowing any cracks repairs to provide long-term benefits.

When In Doubt, Contact a Foundation Crack Repair Professional

All of the information listed here is general, and not all cracks are created equal. If you notice a crack growing or if you are experiencing other symptoms that might point to deeper foundation issues, don’t hesitate to contact a reputable foundation repair company. If all you need is crack filler, we’ll tell you that.

Foundation issues aren’t something to mess around with. It is better to be safe and have the peace of mind that everything is good than to let a potential problem fester.

For any of your foundation crack concerns and foundation repairs needs, contact us for a free quote.

Around the House in Carlsbad, CA


What are the most common problems we see in Carlsbad?

So many of the calls we receive from our Carlsbad customers start with something small. Something that people aren’t even sure is a true problem.

“I have a small crack in my ceiling, should I be worried?”

“I noticed my steps have separated from my foundation, is this a big problem?”

People generally are just around the house and they notice something that wasn’t there before. Then, like we all do, they go to Google and search:

Are you seeing a pattern here? I bet you are….cracks (among a few other things!) So how serious are these cracks and do they REALLY mean a problem is happening underneath your home?

Err on the side of caution ⚠️

Here is our recommendation to Southern California homeowners:

What does it hurt to get it checked out?

If you notice cracks, even if they are just hairline cracks, it’s worth having a foundation repair expert take a look. We live in an area, whether you are talking about Carlsbad or other parts of Southern California, that is prone to movement and changes in the ground around your home.

The cracks you are finding might just be from minor settlement but they truly can be a sign of something bigger. Especially if you are seeing more than one item on that list above. A few other items to keep your eyes on? Countertops pulling away from the wall, cracked tiles, cracked molding, or cracks in the joint where walls meet – these are all potential signs of problems.

We offer free estimates, and perform foundation repairs that can keep your home structurally sound. Call us – ask questions – and have us take a look. We’re here to help and proud to serve Carlsbad and Southern California. Thanks for reading!

Most Common Foundation Issues in Southern California

People in Southern California deal with a very specific set of foundation problems. Because most people have slab foundations, foundation repair and foundation raising in Southern California is different than in other states and other parts of the state. Learn what the common foundation issues are in Southern California as well as how to identify a foundation problem. Once you know you have a problem, you should call an expert at FOUNDATIONS ON THE LEVEL.

Common Foundation Issues and How to Repair Them

Bowing Walls & Wall Cracks

Wall cracks are among the most common foundation problems in Southern California

Look for bowing and buckling of walls. Walls that are bowing and leaning often have cracks as well. This issue is caused by unstable foundations and is typically repaired by pier installation. Sometimes helical tiebacks can be used to repair retaining walls and other walls in SoCal properties.

Foundation Settlement

foundation settlement often causes foundation cracks and other common foundation issues

If you see visible signs that your foundation is sinking or settling, it could indicate major foundation failure. Underpinning with steel push piers or helical piers can help lift and stabilize settled foundations in Southern California.

Floor Cracks & Uneven Floors

floor cracks are often caused by foundation issues

Cracks in the floor of a home or separating between walls and floors can mean that the foundation has settled unevenly. This also causes floors to slope. Sagging and bounciness in floors may accompany cracks. This problem usually requires underpinning with piers or polyurethane injection.

Ceiling Cracks

wall crack repair Southern California

Cracks in your ceiling can also indicate foundation failure. These cracks come in a variety of shapes – spiderweb cracks, angled cracks, and horizontal or vertical cracks. Larger cracks that extend down the wall or occur near doors and windows are usually more serious. Underpinning or slab lifting with polyurethane helps fix this issue.

Sticking Doors & Windows

sticking windows and doors Southern California

If your doors and windows are sticking closed or not closing properly, it may be the sign of movement in your foundation or even foundation failure. If you find this in conjunction with other issues, call an expert right away. Foundation repair and foundation raising can help fix the underlying issues causing this problem.

Foundation Cracks

foundation cracks Southern California

Here in California, we’re more prone to cracking and settling foundations due to our climate and soil conditions. Foundation settlement and upheaval, which is the opposite of settlement, are both very common in Southern California. Cracks can also lead to foundation leakage. Get these cracks fixed right away with underpinning or professional crack injection repair.

free inspections

We utilize foundation underpinning and polyurethane injection for slab leveling to fix all of these issues for SoCal homeowners. Contact FOUNDATIONS ON THE LEVEL for foundation repair solutions in Southern California.