Dig Around Foundation for Waterproofing and Drain Tile
Water is coming through a basement wall or at the floor joint, and you want it fixed from the outside where the water starts.
JMB Builders will dig around a foundation for waterproofing and drain tile across the Twin Cities metro. The wall is exposed down to the footing, cleaned, damp-proofed or covered with a membrane, and perforated drain tile is set in washed stone to a sump or daylight. Then it is backfilled in compacted lifts and graded away. Cracked or bowing walls go to an engineer first. Priced per project after a site visit.
- Priced per project after a site visit
- Wall exposed to the footing and sealed
- Drain tile in stone to sump or daylight
- Licensed MN contractor BC809005
Exterior waterproofing means digging a trench along the wall down to the footing, fixing the outside of the wall, laying drain tile, and putting the dirt back so water is carried away instead of sitting against the basement. It is more work than an inside drain system, but it stops the water at the wall instead of managing it after it gets in.
The dig-out also shows what the wall looks like. Minor cracks get sealed before the membrane goes on. Wide cracks, step cracks in block, or a wall that is bowing or leaning inward are a structural question, and a structural engineer looks at them before the wall is covered up again.
Before any dig-out, check the simple things: gutters, downspout extensions and the grade. Water pooling at the wall from a short downspout is a cheaper fix than a trench.
What you supply
- Photos of the wet area inside and the outside of that wall
- Where the water shows up and when: spring thaw, heavy rain, all the time
- Location of the sump basket if the house has one
- Decks, patios, steps, AC units or plantings along the wall you want kept
- Engineer's report if a wall has already been looked at
What JMB supplies
- Gopher State One Call locate, and hand-digging near meters and service lines
- Excavation along the wall down to the footing, with the soil stockpiled or hauled
- Wall cleaned; minor cracks sealed; damp-proofing or a waterproof membrane applied
- Perforated drain tile in washed stone wrapped in fabric, run to a sump or to daylight
- Backfill in compacted lifts with a final grade sloped away from the wall
- Downspouts reconnected or extended away from the dig
- Photos of the open wall, the tile and the finished grade in your job folder
How it is priced: per project
Quoted in writing from your photos within one business day. What moves the number:
- Length of wall and depth to the footing
- Decks, steps, patios, driveways or AC units that have to be moved or dug around
- Membrane versus damp-proofing, and crack repair found once the wall is open
- Drain tile outlet: an existing sump, a new sump basket inside, or daylight on a slope
- Soil, access, and whether spoils stay on site
- Landscape and lawn repair after backfill
Send photos of the wet spot inside, the outside of that wall, and the yard around it. We walk it and write a firm per-project quote.
How long it takes
One wall usually takes a few days from dig to backfill. A whole house takes longer, set by the wall length, weather and what the wall looks like once it is open.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
One leaking wall
The wet section dug out to the footing, sealed and fitted with drain tile tied into the existing system or a sump, then backfilled and graded.
Full perimeter drain tile
All walls dug out in sections, sealed, and a continuous drain tile loop run to a sump or daylight, then backfilled and graded.
Wall with cracks or bowing
Dug out and left open for a structural engineer to review. Repairs follow the engineer's plan before the wall is sealed and backfilled.
Dig Around Foundation for Waterproofing and Drain Tile: questions, answered
Is exterior foundation waterproofing better than an interior drain system?
Exterior waterproofing seals the wall and drains water away before it reaches the basement, which is why new houses are built that way. Interior systems catch water after it comes through the wall and pump it out. Exterior costs more because of the digging, but it deals with the cause.
What is the difference between damp-proofing and a waterproofing membrane?
Damp-proofing is a sprayed or rolled coating that slows moisture moving through the wall. A waterproofing membrane is a thicker sheet or coating that holds back water under pressure and bridges small cracks. For a wall that already leaks, a membrane is usually the right choice.
Where does exterior drain tile drain to?
The tile runs to a sump basket inside the basement, where a pump sends the water out, or to daylight where the lot slopes enough for the pipe to drain on its own. If there is no sump, adding one is part of the plan and quoted with it.
What if my basement wall is cracked or bowing inward?
Once the wall is dug out, a bowing wall or wide cracks are shown to you and a structural engineer is brought in to look before anything is covered back up. The engineer decides the repair, such as bracing or rebuilding a section. Waterproofing a wall that is still moving does not last.
Will you have to remove my deck or patio?
Sometimes. A deck can often be left in place and the trench dug beside its footings, or a few boards and joists taken off. Patios, steps and walks right against the wall usually come out and go back afterward. That is decided at the site visit and listed in the quote.
Should I try regrading before digging out my foundation?
Often, yes. Short downspouts and soil that slopes toward the house cause a lot of wet basements, and fixing those costs less than a dig-out. If the wall still leaks after the water is carried away, then the exterior dig-out makes sense.
Recent JMB work, from our job log
59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners and for the builders and dealers we sub for. Counts come straight from our job log; no customer names.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
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Read morePage reviewed September 26, 2026 · JMB Builders LLC, MN license BC809005 · All excavation pages
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