New Timber Retaining Wall — 6x6 Treated Timbers With Deadmen
A straight, square timber wall that matches the deck or the fence, built the way the rotted one you are replacing never was.
A new timber retaining wall is built from 6x6 ground-contact treated timbers stacked on a compacted class 5 base, pinned through with rebar, and tied back into the hill with deadmen every few feet, with clean gravel and drain tile behind it. JMB Builders builds them across the Twin Cities metro where timber still makes sense: short garden walls, terraces, and walls beside a wood deck or fence. Priced per linear foot.
- Priced per linear foot of wall
- 6x6 ground-contact treated timbers, rebar pinned
- Deadmen into the hill, gravel and drain tile behind
- 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.
Most timber walls we see are old railroad ties or landscape timbers set on dirt with a few spikes, and they are rotting and leaning. That gives timber a bad name it does not fully deserve. A timber wall built on a compacted base, pinned with rebar, tied back with deadmen and drained with gravel is a square, clean wall that lasts a long time in Minnesota, and it costs less than block for a short wall. It is the right choice next to a wood deck, along a fence line, around a vegetable garden terrace, or anywhere a block wall would look out of place.
The build starts the same as a block wall: a trench dug below the topsoil, class 5 compacted in lifts, and the first timber set level and partly buried. Each course is offset like brick, pinned to the one below with rebar driven through drilled holes, and stepped back slightly into the hill. Every other course gets deadmen, timbers run straight back into the slope with a cross piece on the end, so the soil holds the wall instead of pushing it. Clean gravel and a perforated drain tile go behind the wall before the soil goes back.
We use 6x6 ground-contact rated treated timbers, not the thin landscape timbers from the garden center, and we line the back of the wall with fabric so the soil does not wash into the gravel. Corners are lapped, and the top course is left as is or capped with a flat 2x for a bench edge.
What you supply
- Where the wall goes and how tall, marked with a hose or a string; we stake it with you
- A decision on the top: plain timber, a 2x cap, or the wall tied into a deck or fence post
- Access for a skid loader or a wheelbarrow route for timbers and gravel
- Plants moved out of the way if you want to keep them
What JMB supplies
- A site measure, layout and the utility locate before we dig
- Excavation of the trench and class 5 compacted in lifts under the first course
- 6x6 ground-contact treated timbers, the first course set level and partly buried
- Courses offset, stepped back and pinned with rebar through drilled holes
- Deadmen with cross pieces run back into the hill on every other course
- Filter fabric, clean gravel and perforated drain tile behind the wall, run to daylight
- Backfill, topsoil and seed or sod above the wall, and photos in your job folder
How it is priced: per linear foot
Quoted in writing from your photos, with a reply within one business day. What moves the number:
- Height: each course adds timbers, pins and deadmen, and a wall over the code height is sized by an engineer
- Length and corners; corners are lapped and take longer than a straight run
- Soil: clay has to be dug out farther behind the wall for the deadmen and gravel
- Drain tile run length to daylight
- Access for a skid loader vs. carrying timbers and gravel by hand
- Removing an old timber or tie wall first, with disposal
- Steps built into the wall in timber, or a 2x cap on top
Send a photo from the front and one from the side showing the slope, and the rough length. Short garden walls are often quoted from photos; a wall holding a real grade gets a site measure.
How long it takes
A short garden terrace wall: one to two days. A wall holding a grade change with deadmen and drain tile: two to four days.
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
Garden terrace wall
A low timber wall that turns a sloped bed into a flat vegetable terrace. Two or three courses on a compacted base with gravel behind. The cheapest proper wall for a garden.
Timber wall beside a deck or fence
A wall that matches the wood around it instead of fighting it. Built against or just off the deck framing with its own base, and tied to fence posts where the fence runs along the top.
Timber wall with built-in steps
Steps framed from the same 6x6 timbers, each riser pinned and backfilled with compacted gravel and a paver or gravel tread. Keeps the whole run in one material.
Replace a rotted tie wall with new timber
The old ties come out and go to disposal, the base is built, and a new 6x6 wall goes up with deadmen and drainage. Same look, built right this time.
New Timber Retaining Wall — 6x6 Treated Timbers With Deadmen: questions, answered
How long does a treated timber retaining wall last in Minnesota?
A long time, if it is built on a compacted gravel base with gravel behind it so the wood is not sitting in wet soil. The walls that rot in ten years were set on dirt with clay packed against the back. We use 6x6 ground-contact rated treated timbers, fabric and clean gravel behind the wall and a drain tile at the base, which keeps the timbers drying out between rains. It will not last as long as block, and it costs less; that is the trade.
What are deadmen in a timber retaining wall?
Deadmen are timbers run straight back from the wall into the hill, with a short cross piece pinned on the far end, so the soil behind the wall anchors it instead of pushing it over. They go in every few feet along the wall on every other course. A timber wall without deadmen leans forward within a few winters; it is the single biggest difference between a wall that holds and one that does not.
Can you build a timber wall over the code height?
Timber walls are best kept short. A wall over the code height has to be sized by an engineer whatever it is made of, and at that height block with geogrid is usually the better wall. If you need to hold more grade in timber, two short walls with a terrace between them keep each wall in the range timber handles well.
Do you use landscape timbers from the garden center?
No. The thin, rounded landscape timbers sold for edging are too light for a wall that holds soil and are not always rated for ground contact. We use full 6x6 ground-contact treated timbers, pinned with rebar through drilled holes. They are heavier, straighter and the wall stays square.
Does a timber wall need drainage behind it?
Yes, as much as a block wall does. Water held in the soil behind a timber wall rots the wood from the back and pushes the wall in the frost. We line the back with filter fabric, fill behind with clean gravel, and set a perforated drain tile at the base run out to daylight or a low spot. Then the soil goes back on top of the gravel.
Timber or block for a short retaining wall?
Block lasts longer and gives you curves and a capped top. Timber costs less, goes up faster and looks right beside a wood deck, a fence or a vegetable garden. For a straight wall under the code height where the look fits, timber is a fair choice. For a wall along the driveway, a curved wall, or anything you want to outlast the house, go block.
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.
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Read morePage reviewed October 1, 2026 · JMB Builders LLC, MN license BC809005 · All pavers pages
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