Basement Waterproofing in Lansing, MI
Leaks at the floor joint, wet walls after snowmelt, water in window wells. Find the source and fix it.
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Where basement water comes from
Water usually gets in at a few predictable spots. Knowing which one you have is what separates a $300 fix from a $10,000 system.
- The cove joint where the wall meets the floor slab. Water under pressure from saturated soil comes up here.
- Wall cracks, especially in poured walls, and mortar joints in block walls.
- Window wells that fill with water because they have no drain or cover.
- Pipe and utility penetrations through the wall.
- Surface water from short downspouts, clogged gutters or soil sloping toward the house.
Common waterproofing fixes
- Interior drain tile: a perimeter drain under the edge of the floor that carries water to a sump pump.
- Exterior excavation and membrane: dig down, seal the outside of the wall, add drainage, and backfill.
- Crack injection for individual leaking cracks.
- Grading, gutters and downspout extensions to keep water away in the first place.
Typical waterproofing costs
Angi's 2026 data: national average about $5,245, with most homeowners paying $2,460–$8,205. Interior work averages about $3,000 and exterior about $7,000. An interior perimeter drain is listed at $60–$120 per linear foot (Angi, 2026).
Before any digging outside, Michigan law requires a MISS DIG 811 utility locate. A professional contractor should handle it; ask them to confirm.
Testing for radon while the floor is open
Interior drain tile and sump work open up the basement floor, which is also how radon gets in. According to Michigan EGLE, about one in four Michigan homes is expected to have radon above the federal action level, and elevated levels have been found in every county. Testing is inexpensive. If you're doing waterproofing anyway, ask whether the sump lid is sealed and whether a mitigation system would make sense.
Before you sign a foundation or waterproofing contract
- Check the Michigan license. Michigan requires a state license for residential contractors doing work of $600 or more in labor and materials. Look for a residential builder license, or a maintenance & alteration license that lists the right trade (basement waterproofing, concrete, masonry or excavation). Ask for the license number and verify it on the State of Michigan (LARA) license lookup.
- Get proof of liability insurance and workers' comp sent from the insurance agent.
- Get the scope in writing: the repair method, how many piers, anchors or feet of drain, where the water will discharge, who pulls the permit, and what's restored afterward (landscaping, drywall, flooring).
- Read the warranty. What it covers (labor, materials, leaks, movement), for how long, and whether it transfers to the next owner if you sell.
- For big structural jobs, consider an independent opinion. A structural engineer who isn't selling the repair can confirm what's actually needed before you commit thousands of dollars.
- Don't sign under pressure. Per LARA's homeowner guidance, if you were solicited and signed at home, you generally have three days to cancel in writing.
Basement waterproofing FAQs
Interior or exterior waterproofing: which is better?
Exterior waterproofing stops water before it reaches the wall but requires digging down to the footing, so it costs more. Interior systems collect water that gets in and send it to a sump pump; they cost less and work year-round. Angi's 2026 averages are about $3,000 for interior and $7,000 for exterior work. Many homes need a mix, plus better grading and downspouts.
Will waterproofing paint fix my leaking basement?
Usually not on its own. Coatings can help with minor dampness, but they don't relieve water pressure from outside. Painting over an active leak can trap moisture and peel. Find the source first.
Why does my basement only leak in spring?
Snowmelt and spring rain saturate the soil around the foundation when the ground below is still frozen or wet, so water pushes in through cracks, the joint where the wall meets the floor, and window wells. That's a common Michigan pattern.
Do I need a permit for waterproofing?
Not always. Excavation or structural work often does require one, and permit fees vary by community. Ask the contractor whether a permit is needed and confirm in the contract that they'll pull it.
Prefer to talk?
Call and describe what you're seeing in the basement or crawl space. You'll be connected with a local foundation and waterproofing contractor that serves your area.
Estimates are provided by the contractor. Repair methods, pricing, warranties and scheduling are set by them, not by this website.