When evaluating foundation cracks for foundation repair, the first question to ask yourself is, “Are the cracks a symptom of vertical movement (settlement or heaving) or horizonal movement (bowing/leaning)?”
Once you understand this, you can know how to properly repair the foundation to permanently resolve the issues present. One of the biggest differences when hiring a foundation repair company is finding one that can diagnose the foundation problems correctly.
STEP 1 – IDENTIFY IF HORIZONTAL OR VERTICAL MOVEMENT
After we have evaluated if there is horizontal movement, vertical movement, or sometimes both, then we can fully assess what repairs would be needed, and any other waterproofing measures that may be desired.
WHICH STRUCTURAL REPAIRS FOR WHICH CRACK TYPES:
- Settlement or Heaving = Piering or Posts and Footings
- Horizontal Movement = Wall Bracing and/or Crack Repair (Several Options) and Sometimes Excavating and Pushing the Wall Back to Level.
- Basement Waterproofing = Secondary Consideration of Options (For a different article)
READING FOUNDATION CRACKS SIMPLIFIED:
It definitely gets more complicated that this, but the rule of thumb on quickly reading cracks is this:
Horizontal Movement or Bowing
When the crack starts at the bottom corner and comes up to the middle of the wall, or is a horizontal cracks, this is signs of bowing
Horizontal Movement or Bowing
If there is horizontal cracking, or what can sometimes be an “envelope crack”, because it looks like an envelope, this almost always due to horizontal movement or bowing.
Vertical Movement or Settling
Cracks starting from the middle and leading up to the top corners are typically clear signs that is the foundation is settling, heaving or both.
HOW TO IDENTIFY MOVEMENT ON REAL LIFE FOUNDATION CRACKS
Now that I have helped simplify what are the basic ways to identify crack patterns, I want to show real life examples and how they might look based on different scenarios and foundation type
1. Stairstep Foundation Crack (Vertical Movement or Settling)
What makes this crack an indicator of vertical movement? Almost every time when the top of the crack is leading toward the top corner it is showing that the right side of the this wall has dropped. This may mean the whole wall, or just the side portion.
2. Exterior Vertical Corner Crack (Horizontal Movement or Bowing)
Cracks such as this are almost always signs that the wall is bowing in, or horizontal movement. These corner is the strongest part of the wall, so when the middle of the wall begins to bow in due to soil and water pressure, this corner becomes a “hinge” for the wall to swing on creating the crack in the corner.
3. Horizontal or Envelope Cracks (Bowing or Horizontal Movement)
A crack such as this is very normal on concrete block foundations such as this. When the clay soil expands from high moisture, the wall can buckle in the middle just like this.
4. Stairstep Crack in First Floor Brick (Vertical Movement or Settling)
Many times when there are several cracks in the brick of the home like this, it is because the foundation is going up and down with the seasons. In the dry season it falls and in the wet season, it rises up.
5. Stairstep Crack in First Floor Brick (Vertical Movement or Settling)
This crack is indicating that the foundation has settled to the left on this photo. You can see how the left side of this foundation has dropped 1/2″ or better. You can see the gap around the window and how the left side of the window is lower than the right side. All very common signs.
6. Diagonal Crack From Bottom Corner Into Top Middle (Horizontal Movement or Bowing)
This is the most common type of foundation cracking, as that wall bows in at the top of the wall, the cracks lead to the bottom corners, the strongest point of the wall.
7. Sheetrock Crack on First or Second Floor (Vertical Movement or Settling)
Almost always accompanied with settlement around doors and windows. These sorts of sheetrock cracks always point like an arrow to where the foundation is settling.
8. Horizontal Crack or Envelope Crack (Horizontal Movement or Bowing)
Things types of cracks are most common when you have excessive ground water or high water tables that swell the clay soil lower on the wall. They are also very common on long walls that range 40+ feet.