restump
To renew the stumps supporting a house
restump: replace rotted foundation posts under a house
Restumping is the work of replacing the wooden or concrete posts, called stumps or piers, that sit between the ground and the underside of a house frame. These vertical supports carry the full dead load of the structure plus live loads from occupants and snow. When they rot, sink, or crack, the house begins to sag and crack internally, and restumping becomes necessary to prevent further damage.
Most houses built before the 1960s in warm climates sit on wooden stumps, typically 4x4 or 4x6 timber posts set on concrete footings at the perimeter and under load-bearing walls. Over decades, timber absorbs ground moisture and decays from the base upward, or termites tunnel through it. Concrete stumps crack and spall from frost heave in cold climates or settle unevenly if footings were laid on unstable soil. The house frame sags, doors jam, windows crack, and the stumps themselves may lean or split.
The restumping process
Restumping requires temporary support: hydraulic jacks or adjustable steel shores are placed under the house framing to lift it slightly and carry load while old stumps are removed and new ones set in place. New stumps are either preservative-treated timber or reinforced concrete piers, set on new footings dug below the frost line. The work is slow and incremental, with jacks advanced in small lifts (typically 0.5 to 1 inch at a time) to avoid shock loads or structural cracking. Many houses are restumped section by section over weeks or months.
The cost and complexity depend on house size, soil condition, and access. A house with many interior stumps under bearing walls costs more to restump than a simple perimeter-only design. Poor soil that requires deeper footings, or sites with no crawlspace, add expense. Conversely, a house on a concrete slab requires no restumping; the slab itself is the foundation.
Restumping is not a maintenance task but a major repair, usually undertaken only when settlement damage becomes visible or a structural engineer recommends it. It is commonly called re-piling or re-blocking in some regions, and the term is almost never used for commercial buildings, which rest on different foundation systems entirely.