Boulder Wall Repair — Shifted and Rolled Boulders Reset by Machine
A boulder wall with a belly in it, boulders in the lawn, or a top row that walks every spring — the moved section pulled, the base fixed, and the rocks set back right.
Boulder wall repair is pulling the boulders that have shifted, rolled or slumped out of a boulder retaining wall, rebuilding the base and the backfill behind that section, and resetting the same boulders by machine with their flat faces out and their weight leaning into the hill. JMB Builders repairs them across the Twin Cities metro and north to St. Cloud. Priced per project, quoted from your photos, with a reply within one business day.
- Priced per project, by the section that moved
- Same boulders reset; new ones only where needed
- Base and drainage rebuilt behind the section
- Quote from photos, reply within one business day
- Licensed MN contractor BC809005
Send photos and hear back within one business day — or book a free in-home estimate.
Boulder walls move for the same reasons block walls do, plus one of their own. The common ones: boulders set on topsoil with no base, no drainage stone behind them so the wet clay freezes and shoves, and water running over the top from a downspout or a slope. The one that is theirs alone: round boulders stacked straight up instead of leaning into the hill. Gravity is on the wall's side only when each boulder bears on the two below it and tips back.
The repair starts with a look at the whole wall to see where the movement starts and stops; a belly in the middle usually has loose rock on either side of it. The moved section is pulled with a skid loader or a mini excavator and the boulders are staged and sorted. The base is dug to solid ground and compacted. The bottom boulders go back half buried with their flattest face out, each one bearing on two below and leaning into the bank. Clean drainage stone and filter fabric go behind as the courses go up, the gaps are chinked with smaller stone, and the top is graded so water runs over or around the wall. Split boulders are replaced with matched stone.
A top row that walks, or one belly, is a repair. A wall that has moved along its whole length was built wrong from the base up and is a rebuild: every boulder out, a base under all of it, and the wall reset. We tell you which you have from the photos, and we quote the smaller job when the smaller job is enough.
What you supply
- Photos along the wall and of the section that moved, and one from above showing what is behind it
- Access for a skid loader or a mini excavator to the wall
- Any replacement boulders you want matched: fieldstone, granite or limestone; we order and deliver
- Where the water running over the wall comes from: a downspout, a slope, a neighbor's lot
What JMB supplies
- A look at the whole wall, not just the belly, and a utility locate
- The moved section pulled and the boulders staged and sorted
- Base dug to solid ground and compacted, with the bottom boulders set half buried
- Boulders reset by machine, flat face out, leaning into the hill, each bearing on two below
- Clean drainage stone and filter fabric behind the reset section, faces chinked
- New boulders where the old ones split or are missing, matched to the wall
- Top graded to send water over or around the wall, downspouts extended past it
- Photos of the finished wall in your job folder
How it is priced: per project
Quoted in writing from your photos, with a reply within one business day. What moves the number:
- Length of the section that moved, and whether it is the top row or the whole height
- Boulder size: rocks a skid loader can set vs. ones that need an excavator
- Whether the base under the section has to be rebuilt or only the top rows reset
- Replacement boulders, delivered and matched
- Access: a machine to the wall, or boulders walked in along a side yard
- Fixing what pushed the wall: a downspout, a wet slope, a tree root
Send one photo along the wall, one straight at the moved section, and one from above it. We can tell a reset from a rebuild from those and set up a free in-home estimate.
How long it takes
A top row reset: a day. A full-height section with a new base: two to three days. A wall that has moved along its length is a rebuild and takes most of a week.
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 reply within one business day. Prefer a look in person? A free in-home estimate is always an option.
- 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
Top row reset
The top boulders that creep forward each spring are pulled, the stone behind them topped up, and the boulders set back bearing on the row below with the top graded over them.
Full-height section rebuilt
A belly or a collapse taken out to solid wall on either side, the base dug and compacted, drainage stone added, and the boulders reset from the bottom up and keyed into the sound sections.
Washout behind the wall fixed
Where water has run over the top and carried the soil out from behind the boulders, the void is filled with compacted stone, the top is graded, and the downspout or swale that caused it is redirected.
Boulder wall around a bed or along a driveway
Low decorative walls move too, usually because they were set on mulch. The boulders are reset on a compacted base, half buried, so the mower and the frost leave them alone.
Boulder Wall Repair — Shifted and Rolled Boulders Reset by Machine: questions, answered
Why are the boulders in my retaining wall rolling out?
Usually the boulders were stacked straight up with their round sides out, so nothing holds them but friction. Add wet clay behind them with no drainage stone, and the frost pushes them forward a little each winter until the top row rolls. Water running over the top from a downspout does the same thing faster. The fix is to reset them leaning into the hill, each bearing on two below, with stone behind.
Can you reuse the boulders when you fix the wall?
Almost all of them. Boulders do not wear out; they were set wrong. We pull the moved section, sort the rocks, and reset the same ones with their flattest faces out. Only split boulders or ones that were too round to ever stay put get replaced, matched to the wall.
Do you have to take the whole boulder wall apart?
Only if it has moved along its whole length. A belly, a slumped corner or a top row that creeps is a section repair: that part comes out to sound wall on either side and goes back on a rebuilt base. We look at the whole wall first, because loose rock usually runs a little past the part you can see.
What goes behind a boulder wall?
Clean drainage stone against the back of the boulders and filter fabric between the stone and the soil, so water drains down and out instead of freezing in the clay behind the wall. Many boulder walls were backfilled with the same dirt that came out of the hole, which is why they move. The reset section gets stone.
Can a boulder wall be fixed by hand?
Small boulders in a bed wall, yes. Anything in a real retaining wall is set by machine: a skid loader with forks or a grapple, or a mini excavator for the big ones. We need a path for the machine to the wall; where there is none, the job gets slower and the quote says so.
How do you stop a boulder wall from moving again?
Base, batter, stone and grading. The bottom boulders sit half buried on compacted base. Each boulder leans into the hill and bears on two below it. Drainage stone behind the wall keeps water from freezing against it. The top is graded so surface water runs over or around the wall, and any downspout is extended past it.
Recent JMB work, from our job log
59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners, builders and dealers. Counts come straight from our job log; no customer names.
Get a written quote for this job
Three photos and a sentence is enough: a reply within one business day, or ask for a free in-home estimate. Or text the photos to 763-204-2099.
Related jobs we do
Boulder Retaining Wall — Fieldstone Boulders Set by Machine
A slope that needs holding and a look that fits a wooded or lakeshore lot — boulders set tight, leaned back, on a base and drainage that get them through the freeze-thaw.
Read moreRetaining Wall Drainage — Why Walls Fail in Minnesota Frost
A wall that leans a little more every spring is not a block problem or a stone problem — it is water freezing in the soil behind it. This is how a wall is built so that never starts.
Read moreBoulder Steps on a Slope — Stone Stairs Set Into a Hill
A hill you walk down sideways, turned into a stair of boulders that do not rock — risers you can trust, treads wide enough for a foot, set into the bank.
Read moreRock Wall Landscaping — Garden Rock Walls and Boulder Edging
A bed that needs a real edge, a driveway corner that cars and the plow keep cutting, or a blank front yard that wants a few big rocks — stone set so it stays where it was put.
Read moreDry Stack Rock Wall Repair — Fieldstone Wall Taken Down and Re-Stacked
An old fieldstone wall that has bellied out, dropped a few stones into the flower bed or slumped in one section after a wet spring, stacked back up to stay.
Read moreBlock Steps Installation — Paver and Retaining Wall Block Stairs
Timber steps rotting into the hill, a front walk that ends in a scramble up the grade, or a retaining wall you need to get through — steps built in block that stay level and even.
Read morePage reviewed October 1, 2026 · JMB Builders LLC, MN license BC809005 · All pavers pages
Where we work
Pavers near you
Based in Zimmerman, scheduling across the Twin Cities metro. Closest first: