Top 10 Signs of Foundation Issues

The foundation is one of the most important components of a building. It provides the support and stability necessary for the entire structure to stand. However, foundations can deteriorate over time due to various factors, such as weather conditions, soil movement, and wear & tear.

In thousands of homes across Connecticut, homeowners are discovering naturally occurring iron sulfides called pyrrhotites in their foundations. These sulfides, when exposed to oxygen and water, tend to result in crumbling foundations. This is because the sulfates take up more space than the original iron sulfides, causing the foundation to crack. 

Let’s look at the most common materials of foundations found in New England area:

1. Stone
2. Cinder Block
3. Cement Block
4. Brick
5. Poured Cement
6. Wood
7. Composite Panels

Signs of Foundation Issues

1. Water Staining
2. Efflorescence
3. Gaps in Seams
4. Vertical Cracking
5. Diagonal Cracking
6. Horizontal Cracking
7. Mapping Cracking
8. Pour Line Crack
9. Honeycombing
10. Deterioration

Regardless of the material your foundation is made of, it’s important to be aware of the warning signs that may indicate foundation issues. In this article, we’ll focus on poured concrete foundations, which are the most common type found in the New England area, and go over the top 10 warning signs of foundation issues.

1. Water Staining

   Did you know that water always leaves a signature that it was present. Its signature is in the form of staining. As long as the staining hasn’t been removed, you will know where it was and how much was there. Water staining on the walls or floors of your foundation can indicate that moisture is penetrating through or around the concrete. Staining on concrete can look differently and it’s important to know what the staining can look like. Some of the staining can come in brown lines where it pushes dust and minerals in the water to its outer edge. This is when water comes through the foundation cracking, seams, and penetrations. When water is absorbed by the concrete, like a sponge, it will turn the concrete a darker gray. This happens when there is a lot of water on the other side of the concrete for a long period of time, such as a high water table. Either of these conditions can cause damage or deterioration to the foundation over time. If water is penetrating through the foundation, you should hire a professional to have the cracks, seams, penetrations sealed properly, which will help prevent the water from coming in through the foundation. Keep in mind that this will not stop the water from coming up against the foundation and could cause further issues in the future. Once the work on the inside is done, then work on the outside to help prevent the water from reaching the foundation in the first place. If the foundation is absorbing water from the exterior, then an exterior drain system should be installed to redirect the water away from the foundation.

2. Efflorescence

   Efflorescence appears as a white, chalky powder, or a light crystal-like powder on the surface of the concrete. It indicates moisture or water vapors has been there. Efflorescence, much like the brown staining from water entry, can be from the minerals in the moisture and as it dries up the salts or lime left behind leaves staining. There are two common ways this occurs. The first and most common is when water drains through the footing drains under the concrete floor in a garage or basement/crawlspace and the vapors will rise and come up through the seam between the wall and floor. This shows up as a white powdery or crystal like substance on the walls. If it is heavy, it may indicate the water in the drain pipes is not flowing as much as it used to. Roots or silt/soil could be is trapped in the drain pipe which would slow the water flow down. If it is around your support columns, this indicates moisture is pushing up against the concrete from underneath. This can cause harm to the columns in the form of rot with both wood and metal. Check for pitting on the metal and check for rot or softening of the wood. If you see it on the floor, it probably is from moisture that has been sitting on the concrete and evaporated leaving the mineral deposits behind.

3. Gaps in Seams

   When there are two different pours in the foundation, a gap may be left between the two sections. This gap can allow water to penetrate, which can freeze and cause heaving and damage to the foundation. Addressing gaps promptly is crucial. If the gap is not too large, then simply having the seam hydro-sealed to prevent moisture entry would be best. If there is movement, then it should be evaluated by a foundation professional to help determine the best course of action prior to or in conjunction with sealing this seam. Typically, when there is a seam in place there should be rebar installed so when the new section is poured there will be something for it to attach to that connects the two sections together. If there is a large gap, it may indicate the rebar is missing or is broken. When this occurs, there will usually be more cracking associated with it and bringing in a specialist or engineer will be important.

4. Vertical Cracking

   There is a wide variety of reasons you may see vertical cracking in poured concrete foundations which cannot all be covered in this article. Vertical cracks can be from common shrinkage, settling, or structural movement that can compromise the structural integrity of the foundation and should be evaluated by a professional. There are three things that get taken into consideration with this type of crack. The first is typical shrinkage which is wider at the top and more narrow as it goes down a foundation wall and sometimes disappears. There should be no other cracking related to it. The next is the crack differential. Meaning, if you put a flat surface against the concrete, both sides of the crack should be level. If not, it would indicate that there is some degree of the concrete shifting and that could have other implications. The last is water penetration. If there is water coming through the crack or water stains present from past entry, then the crack should be sealed to prevent further deterioration.

5. Diagonal Cracking

   This type of cracking is typical when concrete hardens and usually comes from a window, foundation pocket, or a change in the elevation of the foundation. You may also see this in the corner of the foundation if there is a shrinkage crack that appears in that corner. This typically stems from the concrete hardening and shrinkage or as some say, ‘pulling from itself’. However, it is important to know the difference between diagonal cracking from hardening and from structural movement. Similar to vertical cracking, if there is differential of the surfaces from either side of the crack or any other cracks branching off of it, this could indicate structural concerns. It is always best to have these type of cracks evaluated further by a foundation specialist to help determine the nature of the crack. This can save you further, more expensive issues down the road, or give you peace of mind if it’s not a concern. The last sign that tells you to take action is if you see water staining, water entry, or history of water entry in these cracks or any cracks. In this case, you should have them evaluated and properly sealed at a minimum to assure there will not be any movement and deterioration from the moisture.

6. Horizontal Cracking

   Horizontal cracks are usually the result of pressure on the outside commonly referred to bearing cracks. This can stem from soil pressure, mechanical pressure, or freezing. Horizontal cracking is more typical in block foundations along a seam of the blocks. With poured concrete, it takes a lot more force for this to occur. Soil pressure on the exterior of the foundation is commonly referred to as hydrostatic pressure. Hydrostatic pressure is a combination of water and soil causing a pressure against the foundation that is greater than what the foundation was intended to handle. Keep in mind that the foundation was intended to handle a downward pressure rather than a sideward pressure. When you have a lot of moisture above the frost line and it freezes, it will create a stronger hydrostatic pressure against the foundation causing the stress that results in horizontal cracking. Heavy equipment like bulldozers and earth rollers that are used to install driveways, for example, can apply more pressure against the foundation then it was intended to handle causing this type of horizontal cracking. When this occurs, this cracking needs to be evaluated further to determine if the cracking is in need of repair, or sealing.

7. Mapping Cracking

   Mapping cracks appear as a series of intersecting lines on the surface of the foundation that look like a map. In the initial stages, the cracking will be very small hairline cracks. As it progresses, different sizes of cracks will appear and can be found anywhere in the foundation. During the advanced stages associated with this type of cracking you will often (but not always) see a dark grey/black discoloration to the concrete that has a white powdery substance on it. It has been thought that the gray/black is a bacteria and the white powder is efflorescence, which makes sense with the type of reaction that is occurring in the concrete. Mapping cracks are related to an interior pressure such as chemical change or mineral change in the concrete. A chemical change often referred to as Alkalinity Salinity Reactivity (ASR) and a mineral change from expansive pyrrhotite. When the mineral pyrrhotite is subjected to oxygen through water it causes the mineral to convert to iron sulfide. This conversion causes an expansion that is more powerful than some concrete depending on the concrete strength or mixture. When this expansion occurs, it will appear at that time that it cannot be repaired. Therefore, the foundation may eventually need to be replaced.

8. Pour Line Crack

   Pour line cracks occur along the line where one concrete pour ended and the other concrete pour started. This is a common visual occurrence, and if mixed properly, will not cause any concerns. When the concrete is poured for a foundation, it typically takes more than one truck load of concrete to fill the forms. If one truck completes pouring, leaves, and the other truck takes too long to pour its load, the first pour will start to dry and will not mix well with the second pour. This will leave what is called a cold joint. This cold joint is a distinct crack along the pour line. When this occurs below the frost line, it is usually not a concern. However, if it has too much hydrostatic pressure, too much frost heaving above the frost line or water entry can make this a problematic structural concern. This needs to be evaluated and a proper repair should be completed to help prevent movement and water entry.

9. Honeycombing

   Honeycombing refers to the presence of voids or air pockets in the concrete. This shows up as an area or patch that looks like stones with voids around them. It is the aggregate in the concrete mix with missing mortar around it. It’s like making a cake or bread and you get a small area that does not get enough moisture, which causes small dry patches. If they are small, they won’t make a difference in the cake or bread. If the pockets are large, it indicates poor mixing, lack of water, and poor workmanship. This is true with the concrete as well and can cause movement in extreme cases and damage to the foundation. In most cases, it is unsightly. If you see moisture intrusion signs, cracking signs, or deterioration, have it evaluated further by a trained professional.

10. Deterioration

    Deterioration can manifest in various ways, including spalling, flaking, chipping or cracking of the concrete. It can be caused by exposure to water, weather conditions, chemicals, or other factors and can compromise the structural integrity of the foundation. We see more deterioration along the outside foundation when people put chemicals or fertilizers up against the foundation in places like golf courses. This should not be confused with the concrete coping that is often put on the foundation. This will age, crack, and deteriorate faster than the foundation itself will.

---

How to Make Foundation Repairs More Affordable

In Connecticut, there is a program set up by CFSIC (Connecticut Foundation Solutions Indemnity Company) that is in charge of allocating the funds related to crumbling foundations. If you are purchasing a home with potential foundation issues and want to get funding at any time in the future, you must do one of the following:

• Have the foundation evaluated by either a professional engineer or a certified foundation inspector listed on the CFSIC website
• Have core samples taken and submitted to CFSIC

If you do not do one of these two things, you waive all rights to future support from the CFSIC program.

In conclusion, it’s crucial to be aware of the warning signs that indicate potential foundation issues, regardless of the material your foundation is made of. Promptly addressing these issues can help you avoid more serious problems and ensure the long-term stability of your building’s structure. If you have any concerns about the state of your foundation, it’s best to consult with a professional foundation contractor who can provide expert advice and guidance.

For more information regarding foundation inspections, you can call Sherwood Inspection Services at 860-646-9983.