There are four most important types of basement walls; and the cracks can form in each one type.

• Masonry (block) wall– These walls are very widespread, made of what many people refer to “cinder block” or “concrete block” They are usually constructed of permeable concrete with openings in the center.  The cracks can form in the block as well as in the “grout” lines that hold the blocks as one.
• Poured concrete wall– This type of wall is gaining reputation in many countries. It is normally created by pouring concrete into wooden or metal “forms”.  When the concrete hardens, the forms are removed; revealing the completed wall.
• Precast concrete wall– This wall is built offsite and then transported to the location, where it can be put in place by a crane.
• Stone, brick or clay (terra cotta) tile– These walls are trendy in older homes; and they tend to have the most cracks due to their construction design and age.

Basement Wall Cracks Basic Causes

Mostly the cracks that appear in the basement walls are caused by;

• Imperfect backfilling when the foundation is built; creating rough pressures against the new wall. Regularly these kinds of cracks are small and at first they cause a little damage. But over the time they grow and create issues.
• Lateral loads that push against the basement walls.
• Foundation movement that results from settling; soil or some other issues.
• Hydrostatic pressure linking wet, heavy soils, and water-related issue.
• Concrete Shrinkage in poured walls.

Most Frequent Basement Wall Cracks Types

• Horizontal cracks– Commonly speaking the horizontal cracks are not caused by the settling issues. They are created by the issues created by the lateral pressure against the walls in the basement.  There are some “warning” signs to look after in a block wall.  Cracks that have opened where wall bowing already begun and those that are more than 1/8 of an inch in the center; are particularly big concern.  Furthermore, another concern is where the horizontal cracks formed within the first courses of block from the bottom; or when those blocks are starting to shift or maybe showing other deterioration.
  
  

  Below are five important causes of the horizontal cracks;

  
  Faulty backfilling– Backfilling the house right after the walls are been poured or throwing leftover construction materials into the backfill field will decay; and cause “open” spaces in the soil and even decaying debris that may enter and clog the French drain and many other waterproofing components. Appropriate backfilling must occur with materials that will allow easy water flow and no soil load issues.

  Overloading– This will occur when the contractor allows overweight and heavy vehicles near the basement walls immediately after backfilling. The weight of the soil is pushing against the basement foundation wall; and can also cause many horizontal cracks.

  Compaction that is too soon or maybe too forceful– Gradually is the best way to backfill against basement walls; and with an element that does not retain water, like the gravel for example. The wall should be backfilled at levels, allowing compaction and natural settling before each next level is added.

  Backfilling all at once is identified as number one cracks cause.

  
  Hydrostatic pressure and moisture loading – Houses with clay-based soil backfilled against their foundations will frequently experience severe cracks when the soil gets wet. These soils are predisposed for expanding when they are wet; and so they create remarkable lateral pressure against the wall. Additionally, when the soil will no longer absorb the moisture; the water itself will create a pressure against walls and floors. Creating what is called “hydrostatic pressure”. Underground springs, high water tables and the poor drainage are key causes for the hydrostatic pressure. But there are also many other reasons as well; for example faulty downspout, leaky sewer line or other drain lines.

  Freeze/thaw process – In climate conditions where the soil next to the foundation walls might experience freezing more than once in a season. This process exerts great pressure on the basement walls; that much so they can crack, bow or tilt.

  Usually these cracks are noticeable as horizontal cracks upper on the foundation walls.

• Vertical cracks– Given that vertical cracks stay straight; they are the least worrying cracks from a structural point of view. These types of cracks are usually a sign of what is identified as differential settlement; in other words, uneven vertical and horizontal pressure).They normally occur when parts of your home settle more rapidly than others; or they settle at uneven pressures.  Even though they are not as serious as the horizontal cracks; they are still an issue to be careful with. They can allow water flow in the basement; and cause great damage.
• Diagonal cracks– Large diagonal cracks may indicate a structural problem; and they need to be carefully inspected by a professional.
• Step cracks– Suitably named because they look like a set of stairs from the side. The step cracks are commonly caused by the uneven settling and shifting soil, happening normally below the footer. These types of cracks may indicate issues with the footer; and they are usually found in the foundation corners.  Like any type of crack, they are a problem since they indicate a hidden force that’s working on the foundation and may allow moisture or even water to enter.
• Cracks at the basement door or window corners– The uneven pressure is main reason for these types of cracks to appear. Especially in poured walls.

Important Things to Know about the Cracks in the Basement Walls

• It is not horribly uncommon for the basement walls to develop cracks over time. Depending upon the severity, the type of the crack, and whether the crack is getting worse; is an sign of whether the crack must to be inspected by professionals. The moisture seepage and also the water flow are at all times an indication that you must contact skilled technicians.
• Looking only at one crack in a small part of your basement wall is not enough to diagnose the overall problem. The state of all foundation walls must be taken into consideration; because the foundation is acting as a unit.
• Most wall cracks are related to poor drainage and moisture issues. If you start to see cracks you should contact foundation professionals straight away.
• Efflorescence is always a sign that you have a moisture issue on the external side of the wall; which will begin over time translating through to the internal part of your property.

If you have questions regarding your basement foundation, or maybe you are experiencing signs of moisture in your home contact the basement professionals at Draintony Toronto for free basement estimation.