What the evidence says about each type of foundation repair

Crack injection and sealing

Filling a crack with a sealant or resin to stop water or tie the sides together. It treats the crack, not the reason the crack opened. License reading: A contractor taking $600 or more in labor and materials needs a LARA residential builder license or a maintenance and alteration license, and which craft fits is our reading of MCL 339.2404. Concrete or masonry are the likely crafts. Permit position: No state or city page we read says whether sealing a crack needs a permit; ask your building department. Engineering position: None is required by the state. Ask an engineer first if the crack has grown.

Estimated range, foundation cracks: $260 to $840 per crack repair. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Foundation cracks Foundation crack types in Michigan and what each pattern usually means

Piers and underpinning

Extending support below a footing, or adding supports under it, so a settled part of the house stops moving. In Michigan exterior footings must extend 42 inches below actual grade, a footing rule from R 408.30522. License reading: A contractor taking $600 or more in labor and materials needs a LARA residential builder license or a maintenance and alteration license, and which craft fits is our reading of MCL 339.2404. Concrete, masonry or excavation are the likely crafts. Permit position: The base code requires a permit to repair or alter a structure, and the city building official decides. Excavation needs a MISS DIG notice, which we read through a summary. Engineering position: The state does not require an engineer, but a city may ask and the code text we read sets only footing depth and soil-bearing rules, so an engineer's design is the sound ask.

Estimated range, piering and underpinning: $890 to $1,950 per pier, installed. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Estimated range, piering and underpinning (per underpinning job): $8,925 to $36,200 per underpinning job. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Piering and underpinning Michigan frost depth: the 42-inch footing rule and what frost heave does

Wall bracing and anchors

Straps, anchors or braces that hold a leaning or bowed wall and stop it moving further. They do not usually straighten the wall. License reading: A contractor taking $600 or more in labor and materials needs a LARA residential builder license or a maintenance and alteration license, and which craft fits is our reading of MCL 339.2404. Masonry, concrete, carpentry or excavation are the likely crafts. Permit position: No page we read names bowing-wall repair as a permit item. Ask your city. Engineering position: The code requires engineered design for walls under groundwater pressure or holding back more than 48 inches of unbalanced backfill, so ask for an engineer's report before a quote.

Estimated range, bowing walls: $70 to $665 per linear foot of wall. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Estimated range, bowing walls (per 20-foot wall section): $1,425 to $13,300 per 20-foot wall section. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Bowing walls Get an engineer's read before you hire a Michigan foundation contractor

Slab lifting

Raising a sunken slab, such as a garage floor or porch, by pumping material underneath. We found no government or extension source on methods or service life, so we describe none as proven. License reading: A contractor taking $600 or more in labor and materials needs a LARA residential builder license or a maintenance and alteration license, and which craft fits is our reading of MCL 339.2404. Concrete is the likely craft, which is our inference. Permit position: State rule R 408.30505 exempts a sidewalk or driveway not more than 30 inches above grade and not over a basement from a building permit. It says nothing about interior slabs, and a city may have its own rules. Engineering position: None is required by the state.

Estimated range, slab leveling: $445 to $1,575 per job. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Estimated range, slab leveling (per square foot, lifted): $4 to $11 per square foot, lifted. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Slab leveling What foundation repair costs in Michigan: our estimates and what shapes a quote

Interior drainage and sump

A channel or perforated pipe at the base of the wall or beneath the slab that carries water to a sump pit and out through a pump. University of Minnesota Extension says it is the most effective interior option when the pipe sits beneath the slab inside the footing. License reading: A contractor taking $600 or more in labor and materials needs a LARA residential builder license or a maintenance and alteration license, and which craft fits is our reading of MCL 339.2404. A sump and its discharge piping are plumbing work under MCL 339.6107, so ask who does the plumbing. Permit position: Warren, Sterling Heights, Dearborn and Westland list waterproofing, sump or interior drain lines on their plumbing permit fee charts. Engineering position: None is required by the state.

Estimated range, drainage: $2,375 to $18,400 per project. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Estimated range, sump pump: $840 to $2,625 per pump, installed. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Drainage Where a Michigan sump pump may discharge, and who may install one

Exterior drainage and waterproofing

Digging down the outside of the wall to add drain tile and a coating or membrane. University of Minnesota Extension calls it the most costly and also the most effective water control approach, and says it must drain to a sump with an airtight cover. License reading: A contractor taking $600 or more needs a LARA license, and waterproofing a basement is a named craft on the maintenance and alteration license. Permit position: Ann Arbor prints basement waterproofing as a building permit item with a grading permit, Dearborn lists waterproofing as a renovation permit item, and Livonia has a waterproofing application checklist. Excavation needs a MISS DIG notice. Engineering position: None is required by the state.

Estimated range, basement waterproofing: $4,375 to $13,500 per project. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Estimated range, basement waterproofing (per square foot, interior system): $4 to $12 per square foot, interior system. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Estimated range, drainage (per linear foot, exterior French drain): $11 to $45 per linear foot, exterior French drain. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Basement waterproofing Basement waterproofing permits in Michigan, city by city

Crawl space encapsulation

Sealing the ground and walls of a crawl space. The 2015 IRC route for an unvented space asks for a Class I vapor retarder with sealed 6-inch overlaps, continuous exhaust or conditioned supply at 1 cfm per 50 square feet, and insulated perimeter walls; it names no dehumidifier and no liner thickness, and vented crawl spaces remain code-compliant. License reading: A contractor taking $600 or more needs a LARA license. Insulation work, concrete and excavation are the nearest named crafts, which is our inference, and a fan or dehumidifier may involve other licenses we did not verify. Permit position: The city decides whether a permit and inspection apply; we found no Michigan page that says so for encapsulation. Engineering position: None is required by the state.

Estimated range, crawl space encapsulation: $2,300 to $15,300 per project. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Estimated range, crawl space encapsulation (per square foot of crawl space): $3 to $12 per square foot of crawl space. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Crawl space encapsulation Crawl space encapsulation and what the 2015 code actually requires

Radon system

A pipe and fan that draw radon from beneath the home and vent it outdoors. EGLE says sealing floor cracks alone will generally not solve it, and that radon testers and mitigators are not licensed or regulated in Michigan. License reading: Michigan does not license radon testers or mitigators (EGLE); the national bodies NRPP and NRSB offer voluntary certification, which we did not verify. Permit position: Sterling Heights lists a $125 radon line on its plumbing permit chart; we found no equivalent line for the other cities we researched. Engineering position: None is required by the state.

Estimated range, radon mitigation: $1,075 to $2,425 per system, installed. A model built from published national ranges and adjusted by Michigan wages, not a quote.

Radon mitigation Radon in Michigan: EPA zones by county, test kits and what a fix involves