Types of Foundation Cracks and How to Repair It?

Foundation cracks trigger a number of questions;

  1. Is this a structural crack that compromises the strength and stability of the wall?
  2. Will the crack get bigger over time?
  3. What caused it?
  4. Will the crack allow water to leak inside the foundation?
  5. What can be done to fix it?

Leaving these questions unanswered can cause any house owner to lose sleep. So, answer all these questions, let’s understand that foundation cracks in detail.

Types of Foundation Cracks

Types of Foundation Cracks and How to Repair It?

1. Vertical Crack:

This type of foundation crack goes straight up and down or slightly diagonal, within 30 degrees. Vertical cracks are of least concern and are commonly seen in almost all the houses. In fact, it is very rare to have a concrete foundation that does not have one or two vertical cracks.

They occur because concrete is very strong under compression, but cracks easily under tension. Most houses will see one, two or even three vertical cracks to form within the first couple of years after construction. These cracks are not a real structural concern, but they can allow water seepage during heavy rains.

Recommended Read – How to Prevent Basement Water Seepage?

Again, this is normal and common. The solution to vertical cracks is usually simple, inexpensive and permanent.

We recommend you to fix vertical cracks by using urethane or epoxy injection. In short, the material is injected through small holes drilled into the crack face from inside. A sealing material is injected under pressure and the crack is well sealed.

The material is also flexible so that the crack will not re-open in the future. Fixed once and fixed forever.

2. Diagonal Cracks:

A diagonal foundation crack is one that runs from about 30 to 75 degrees. Many times, diagonal cracks will be wider at one end than the other, and sometimes, the crack will be very narrow (also called a hairline crack).

Diagonal cracks are usually caused by differential settling of the foundation and can occur when the house is new or old. Differential settling is caused by a change in the ground conditions under the foundation footings.

One part of the house’s foundation, say one corner, settles a little lower into the ground while the rest of the foundation stays fully supported. This causes tension on the foundation just like described above. But this tension is not in a straight horizontal vector, but horizontal and vertical.

The foundation cracks at an angle rather than straight up-and-down. It is the reason why most of the diagonal cracks are wider at one end. Because the foundation is moving in two directions, part of the crack is also wider and will indicate the exact settling area.

This differential settling could be caused by the house being built on a hill or because of changes in the soil conditions due to excessive rain or drought. It cal also be caused by simple things like having your gutter downspouts drain too close to the house’s foundation on one side or at one corner.

Diagonal cracks can be repaired in the same manner as vertical cracks, but more injection material is used to account for any additional future movement. Repairing diagonal cracks also calls for determining the cause and position of the differential settling.

This is where a certified home inspector, one who has specialized training in structural and foundation issues, can be of help.

3. Horizontal Cracks:

Foundation cracks that run sideways are the most serious type of cracks. They are sometimes seen in poured concrete foundations but more commonly in concrete block and brick foundations.

Horizontal cracks are caused by a bowing foundation. The foundation wall’s exterior is usually covered by the backfilling of dirt and gravel. If this backfill is improperly done, it does not get proper drainage or gets overly compressed (many times by the construction equipment that was used to build the house) the excessive pressure against the foundation wall cases it to bow inwards.

Sometimes there is excessive rain which can also be followed by a freeze. This can increase the hydrostatic pressure behind the foundation wall and cause it to bow inwards. Bowing foundations are serious and can lead to structural failure of the foundation and collapse of the house.

There are a couple of different techniques for horizontal foundation cracks repair. Some involve the installation of high-strength strapping on the interior of the foundation to keep the wall from bowing further.

Sometimes a number of reinforcing posts or braces are installed in the basement or crawlspace. There are also techniques that use anchors buried in the surrounding soil that pull the foundation wall back out and secure it.

Regardless of the solution, a bowing foundation should always be evaluated by a licensed Structural Engineer and the repair technique and plan be determined by him/her. Bowing foundations are serious and their repair should always be done by a professional.

4. Step Cracks:

Sometimes the cracks are not at the foundation but are seen on the exterior wall above the foundation. This is commonly seen in brick or concrete block exterior houses. Step cracks should be treated just like diagonal cracks and are the result of differential settling of the house.

If the cracks are only in the mortar joints between the brick or block, the problem is usually not serious and can be repaired by the re-pointing of the mortar. However, if the brick or block is displaced such as moved in or out from the material on the other side of the crack or the cracking extends through the blocks, the problem may be more serious.

Step cracks should always be evaluated by a Certified Home Inspector or a Structural Engineer to determine their severity.

What Causes Foundation Damage?

For the vast majority of issues, water is the primary culprit. In fact, variations in moisture cause components of the soil to swell or shrink, leading to movement beneath your foundation.

Recommended Read – How to Prevent Water Damage?

Your property may be more susceptible to foundation damage if:

  1. It was built on expansive clay
  2. It was built on improperly compacted fill soils
  3. The area around the foundation has poor drainage
  4. You live in an area with extreme seasonal changes
  5. You experienced a plumbing leak below your home
  6. Tree roots are growing too close to your home
  7. An earthquake, flood or drought compromised the structure

Those soils highest in clay content are generally more susceptible, while those lowest in clay content are the least ones. In some areas the movement is insignificant; in others, it is quite noticeable.

When unstable soils are used as a base, the movement is transferred to the foundation. Since soil movement is rarely uniform, the foundation is subjected to a differential or upheaval. The problem shows up in both slab, and pier and beam type foundations.

If all the soil beneath a foundation swells uniformly, there usually is no problem. Issues occur, only when the part of the home settles. Then, the differential movement causes cracks or other damages.

Issues resulting from foundation settlement:

  1. Damage to the structure
  2. Loss of real estate value
  3. Tripping hazards
  4. Unsightly cracks
  5. Equipment malfunctions

Whatever the cause, settlement can destroy the value of your home and even render it unsafe. If you see any cracks in the foundation, don’t delay in taking immediate actions. The longer you wait, the more your foundation will sink, causing further costly damage.

What Are The Signs Of Foundation Problems?

Are you wondering if you have foundation issues? All foundations will settle with time, but problems arise when this settlement is uneven or extreme. Here are the common signs of foundation stress:

1. Exterior Warning Signs

  1. Wall rotation
  2. Separation around garage door, windows and/or walls
  3. Cracked bricks
  4. Broken and/or cracked foundation
  5. Displaced moldings

2. Interior Warning Signs

  1. Misaligned doors and windows
  2. Cracked sheetrock
  3. Cracks in floor
  4. Uneven floors

Bulging floors, cracked walls, and doors that won’t close are all signs of foundation distress. Sixty percent of all houses built on expansive soils suffer from foundation distress. The trouble occurs when the foundation heaves or settles, causing cracks and other damage.

This differential movement largely occurs due to differences in soil moisture. Loss or gain of soil moisture can cause serious shrinkage or swelling.

If the frame of a house does not begin to distort until after three or more years of satisfactory performance, it is doubtful that the distortion is due to a full-depth foundation settlement, which is always evident by matching cracks.

Cracks occur at each side of a portion of the foundation wall that is undergoing downward movement caused by soil bearing failure.

Settlement cracks are nearly always vertical, and they should not be confused with cracks that occur when a wall is subjected to lateral movement from soil pressure.

Foundation Wall Cracks can Often be Repaired Quickly and Affordably

With the exception of tiny shrinkage, any foundation cracks should be inspected by an expert. Since structural cracks are likely to become more severe over time, get your crack inspection done sooner rather than later.

Wondering whom to hire for foundation crack repair in Cincinnati? Dry Effect is here to assist you in foundation crack repair, basement waterproofing, mold removal and more. We are one of the most-recommended names when it comes to basement waterproofing and cracks repair.

With us, you can be assured of quality services at competitive rates. Our knowledgeable technicians are updated about the latest methods to repair foundation cracks. After a thorough inspection of the site, we can suggest the right solution that is affordable, effective and durable.

Contact us or give us a call right away! We are happy to respond to your queries and ready to clear your doubts on foundation crack repair.

About Lisa McIntyre

Lisa McIntyre has always resided in the Greater Cincinnati and Northern Kentucky. She graduated from University of Cincinnati with a degree in Applied Science. Ultimately, her passion for science and teaching came to fruition after her husband requested her assistance in developing Dry Effect Restoration Services. She was able to develop her knowledge, degrees and certifications further in many indoor air quality associations and organizations. Thus allowing her to educate Realtors and Insurance Agents on the damages that many common indoor air quality irritants and water bacterial growths can lead to in ones home or business. Over 10 years later she’s glad to have taken the leap of faith to assist her husband what seemed to be a fun project into a lifetime achievement and to see the individuals she teaches prosper from their newly found knowledge.

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