Serving Cambridge, MA and surrounding areas(617) 613-7966
A settled slab or sunken foundation gets worse every winter in Cambridge. Polyurethane foam injection and mudjacking restore your concrete to its original level without the cost and disruption of full replacement.
Foundation raising in Cambridge corrects settled concrete by injecting material beneath the slab to fill voids and lift it back to its original level — most residential jobs are completed in a single day, with polyurethane foam projects ready to use in hours.
Cambridge's combination of aging triple-deckers, fill-land geology near the Charles River, and 48-inch annual frost cycles creates near-constant pressure on footings and slabs that were never designed for modern loads. When a basement floor tilts, a driveway apron drops, or a front walkway settles away from the steps, the underlying void is getting larger with every freeze-thaw cycle. A lifted slab stabilized this season costs a fraction of the replacement job that waits for next spring.
If the damage extends beyond a settled slab to a compromised foundation wall or inadequate footing depth, we can assess whether foundation installation is a more appropriate solution before committing to a lift.
Diagonal cracks running along mortar joints in a staircase pattern are a classic sign of differential settlement, where one section of the foundation or slab has dropped independently of its neighbor. Left unaddressed, those cracks widen, allow water infiltration, and eventually compromise the masonry's structural continuity.
When a foundation settles unevenly, the wood frame above it racks out of square, causing doors and windows to bind in their frames or stop latching cleanly. In Cambridge's older triple-deckers, this symptom often appears first on the ground floor and spreads upward as settlement continues.
A floor that visibly slopes toward one side, or one that flexes noticeably underfoot, indicates that the supporting slab or subfloor framing has lost bearing. In Cambridge homes with basement slabs poured over fill soils, voids beneath the concrete are often the cause, and they grow larger each time rainwater channels under the slab.
Settlement creates negative slope that directs surface runoff toward the foundation rather than away from it. Water pooling at exterior walls accelerates sub-base erosion, which in turn causes further settlement — a cycle that gets significantly more expensive to break the longer it runs.
The right lifting method depends on the slab's load requirements, how quickly the area needs to return to service, and what is driving the settlement. We assess all three before recommending an approach.
Polyurethane foam injection is the faster and cleaner option for most Cambridge residential jobs. We drill 5/8-inch holes through the slab, inject a two-part expanding foam that fills sub-base voids and lifts the slab with controlled precision, then patch the holes. The foam cures in roughly 15 minutes, so a driveway or walkway is back in use the same day. For occupied Cambridge rental units, that turnaround matters.
Mudjacking pumps a dense slurry of water, Portland cement, and soil through larger holes to achieve the same void-fill and lift effect. The material requires 24 to 48 hours to cure and leaves a slightly larger patch footprint, but the material cost per cubic foot is lower — making it a practical choice for large-area slabs where polyurethane volume would be prohibitive.
In cases where the sub-base instability is too severe for lifting alone — particularly on Cambridge's fill-land properties near the Charles River and Kendall Square where Boston Blue Clay continues compressing beneath the slab — we assess whether deeper intervention is needed. Proper concrete footings taken to the 48-inch frost depth can transfer loads past unstable fill and into competent soil, providing the stable base that lifting alone cannot create.
Every lifting project starts with an on-site assessment. We look at the slab's condition, the cracking pattern, drainage around the perimeter, and any visible signs of ongoing soil movement. If the concrete itself is too deteriorated to lift intact, we say so clearly and explain when full replacement is the better path.
Best for occupied properties where same-day return to service is required and access holes need to be minimally visible.
Best for large-area slabs where material volume would make polyurethane cost-prohibitive and a 24 to 48-hour cure window is acceptable.
Best when cracking or sub-base conditions suggest lifting alone will not produce a durable result and deeper foundation work is warranted.
Cambridge sits in one of the more challenging geological environments for concrete longevity in Massachusetts. East Cambridge, Kendall Square, and the neighborhoods closest to the Charles River were built on filled tidal marshland in the 19th century. Beneath that fill lies Boston Blue Clay, a marine deposit well-documented in Greater Boston geotechnical studies for its tendency to compress slowly under sustained load. Buildings and slabs on this ground can see gradual settlement for decades after original construction, well beyond what ordinary warranty periods cover.
Beyond the fill-land zones, Cambridge's residential neighborhoods are dominated by wood-frame triple-deckers built between roughly 1880 and 1930. Many rest on rubble stone or early-pour concrete foundations never designed to current code standards. Combined with Massachusetts's 48-inch frost depth and over 100 annual freeze-thaw cycles, these older foundations see cumulative seasonal movement that adds up visibly over time.
We regularly perform foundation raising work across Cambridge and into surrounding communities. Homeowners in Somerville face similar triple-decker and fill-soil conditions, while properties in Medford contend with comparable frost-depth and aging-foundation challenges. Early intervention in any of these areas reliably costs less than waiting for symptoms to reach the structural replacement threshold.
Reach out by phone or the estimate form and describe what you are seeing. We reply within 1 business day to schedule the on-site assessment at a time that works for you.
A crew member visits, inspects the settled concrete, evaluates sub-base conditions and drainage, and gives you a clear written scope with costs broken out by method. No obligation to proceed.
Holes are drilled, material is injected, and the slab is raised to its original level in a controlled sequence. For polyurethane jobs, the area is typically back in use the same day.
Injection holes are filled flush with matching material, the work area is cleaned, and we walk through the completed lift with you before leaving the site.
Free on-site estimate. No obligation. We reply within 1 business day.
(617) 613-7966We know which Cambridge neighborhoods sit on marine clay fill and which sit on stable till, and we scope lifting projects accordingly. On properties near Kendall Square and the Charles River, we assess whether sub-base conditions require deeper intervention before recommending a lift.
Every structural foundation project is managed by a Massachusetts Construction Supervisor License (CSL) holder and registered under the state's Home Improvement Contractor (HIC) program, which provides consumer fund protection for residential work.
More than 50 foundation and slab projects completed in Cambridge since 2022 — a volume that reflects consistent local demand and repeat work from property managers who know their buildings will be assessed honestly rather than sold a lift that will not hold.
We complete lifting work on a schedule that accounts for Cambridge's frost window. Slabs lifted and stabilized before the ground freezes face less risk of re-settlement than those left through another Massachusetts winter before being addressed.
The combination of fill-soil knowledge, state licensing, and genuine local project volume means every assessment reflects Cambridge's specific conditions rather than generic residential concrete practice. That carries through to the cost estimates and honest advice on when lifting is the right call versus when a different repair is needed.
Massachusetts CSL and HIC credentials are publicly verifiable through the Mass.gov license lookup. Foundation repair permits are issued by the Cambridge Inspectional Services Department.
Full foundation construction for new builds and complete replacements when raising is not the right solution.
Learn moreFrost-depth footings that provide the stable base a lifted or rebuilt foundation needs to hold long-term.
Learn moreContact Cambridge Concrete today for a free foundation raising estimate in Cambridge, MA — every week of delay adds frost-cycle wear to a problem that only grows.
