How Are Pasadena Craftsman Foundations Retrofitted?

When the existing brick or early concrete foundation is sound, the retrofit works with it. Epoxy-set anchor bolts are drilled into the foundation wall and bonded with structural epoxy, clamping the sill plate against sliding and overturning. The engineer verifies the masonry can develop the bolt loads, specifying edge distances and spacing that account for century-old materials rather than assuming modern concrete capacities. Cripple walls above get structural plywood sheathing with engineered nailing, turning the framed pony walls into shear panels. Deteriorated mortar gets repointed with compatible mortar, and individual failed bricks are replaced with matching units so the wall regains its bearing capacity. The engineer distinguishes cosmetic weathering from structural distress: surface spalling is repaired in place, while stepped cracking or bulging signals movement that needs investigation before any bolting begins. Drainage and grading corrections accompany the structural work, because the moisture that destroyed the mortar will destroy the repair if it is not addressed.

Some foundations are past repair: mortar reduced to sand through the full wall thickness, bricks crumbling under hand pressure, or walls displaced beyond what repointing can fix. In these cases the house is lifted and the foundation replaced. The lifting contractor raises the house evenly on cribbing, the old foundation comes out, and a new reinforced concrete foundation goes in with continuous footings, anchor bolts, and, where the design calls for them, new braced cripple walls. The house is then lowered, leveled, and reconnected. Sectional underpinning offers an alternative when lifting is not feasible. The foundation is replaced in short segments, typically four to five feet at a time, with each new concrete section cured before the adjacent section is excavated, so the house is never left unsupported. The method is slower but avoids the logistics of a full lift on tight lots. Both approaches end with the same result: a continuous reinforced concrete foundation designed for current seismic demands, with the sill bolted and the cripple walls braced.