Structural crawl space repair. The work before encapsulation.

Sistering means attaching a new joist alongside the existing damaged one, mechanically fastened with structural screws and construction adhesive, so the new joist carries the load while the old one stays in place. It’s appropriate when the original joist has localized damage (rot at one end, a long crack mid-span) but is otherwise sound along most of its length. Replacement means cutting out and removing the original joist entirely and installing a new one. It’s needed when the joist is rotted along most of its length, has been attacked by termites or carpenter ants, or has structural cracks that compromise the full length. We make the call at the inspection — sistering is roughly half the cost of replacement and is the right answer about 70% of the time on East TN homes.

Stabilization (jacking the pier and re-leveling, sometimes pouring a new concrete footing under it) works when the pier post itself is sound but has settled or shifted — which is most East TN cases, especially in clay-soil areas like Oak Ridge and Farragut. Replacement is required when the pier post is cracked through, mortar has crumbled away, the post has rotated, or the post is wood and rotted at the base. We use steel adjustable jack posts for replacements where appropriate, or we rebuild with masonry block piers on a poured footing when the original was a single brick or stone column. East TN code requires pier post footings to be below the frost line (12 inches in Knox County).

Yes — sump pump installation is a common precursor to encapsulation when the crawl has a history of standing water or active groundwater intrusion. We install Zoeller M53 or M98 commercial sump pumps with a battery backup option, plumbed to discharge well away from the foundation (typically to a daylight exit on a slope, or to a French drain that takes water to the street). The sump basin is set in the lowest point of the crawl floor and tied to a perimeter French drain when needed. We don’t install consumer-grade plastic sump pumps — they fail at the worst times.

Often, yes — though the answer depends on what’s causing the sag. If it’s joist deflection from rot or undersized joists, sistering or replacing the affected joists usually restores the floor. If it’s joist deflection from a removed bearing wall or modified support structure (common in 1960s–1970s remodels), we need a structural engineer’s evaluation before we touch anything — we can recommend one. If it’s pier settlement, we lift the affected piers back to grade and re-shim. Severe sagging that’s been left for years sometimes can’t be fully restored without removing and rebuilding the floor structure — we tell you that at the inspection rather than promising a miracle.

Highly variable. Spot repairs (sistering a couple of joists, stabilizing one or two piers): half a day to one day. Drainage corrections plus sump pump install: one to two days. Major repair (multiple joist replacements, multiple pier rebuilds, sill plate sections): two to four days. We schedule structural repair separately from encapsulation — the repair has to be complete and inspected before the liner goes down. If both are happening, the encapsulation install follows the structural work, typically within the same week.