A foundation wall problem is different from a settlement problem, and confusing the two leads to the wrong repair being sold. Settlement is the house going down. A wall problem is the wall being pushed sideways by the soil behind it.
How to Tell Which One You Have
The direction of the crack is the giveaway.
A horizontal crack running along a block wall, often near the middle third of its height, means lateral pressure. The wall is bending inward. This is the pattern that needs taking seriously.
Stair-step cracking following the mortar joints can mean either, depending on whether the wall has also moved inward. Put a straightedge or a plumb line against it — if the middle of the wall is further into the room than the top and bottom, it is bowing.
Vertical cracks are more often settlement or shrinkage than pressure.
What Pushes a Wall In
Water is nearly always involved. Saturated clay behind a wall exerts far more pressure than dry clay, both from the weight of the water and because our clay expands as it wets. Add a blocked or absent drain, guttering that discharges next to the wall, or a grade that falls toward the house, and the load on that wall goes up substantially every time it rains.
Frost is a minor factor in central Alabama compared with further north, but heavy vehicles parked close to a wall and tree roots are both worth ruling out.
The Repair Options
Carbon fiber straps are bonded vertically to the inside face of the wall to stop further inward movement. They are low-profile, do not require excavation, and suit walls with limited deflection — usually up to about two inches of bow. They hold the wall where it is; they do not straighten it.
Wall anchors use a plate on the inside of the wall connected by a rod to an anchor plate buried in stable soil out in the yard. They stop movement and, tightened gradually over months, can recover some of the bow. They need access to the yard and they leave small plates visible on the wall.
Helical tiebacks do a similar job to wall anchors where there is not enough yard to place an earth anchor, screwing into the soil at an angle instead.
Rebuilding the wall is the honest answer when deflection is severe or the block has fractured through. It is the most expensive route and the one contractors are least keen to quote, which is worth knowing when you are comparing proposals.
Fix the Water First
Whichever repair is chosen, the drainage that caused it needs correcting or the pressure simply returns. Extending downspouts well away from the house, correcting the grade so it falls away, and installing or clearing a footing drain are unglamorous and cheap next to structural work — and they are the difference between a repair that lasts and one that is revisited.