Retaining Wall for Walkout Basement Patio — Wing Walls and Drainage
Your walkout door opens onto a muddy slope or a patio that fills with water every rain, and the hillside keeps sliding toward the door.
JMB Builders builds the retaining wall for a walkout basement patio across the Twin Cities metro and north to St. Cloud. Block wing walls hold the hillside back on each side of the door, the grade steps down to a paver patio sloped away from the house, and drain tile behind the walls and a drain in front of the door carry water off. Priced per project after a site measure.
- Priced per project after a site measure
- Block wing walls on each side of the door
- Patio sloped away from the door sill
- Wall drainage tied to an outlet
- Licensed MN contractor BC809005
A walkout basement sits where the hill drops. The ground beside the door is higher than the door, and every drop of rain on that hillside wants to run to the lowest spot, which is the door. Most walkout patios that flood are flat, or they slope toward the house, and the walls on each side have no drainage behind them.
The fix is shaped around the door. Retaining walls, usually block wing walls, step down on each side and hold the hill back. Behind each wall goes drainage stone and a perforated drain tile, sloped to an outlet, so water in the hillside does not push the wall over or leak out at its base. In front of the door, a paver patio slopes away from the sill, and where the yard is too flat for that, a channel drain or catch basin at the patio edge takes the water to daylight or a pop-up.
Tall walls near a house can need a permit and an engineer's design, and a wall close to the foundation has to be planned so it does not load the basement wall. We measure the heights on site and tell you which applies before quoting.
What you supply
- Photos of the walkout door, the slope on each side and the patio area, after a rain if possible
- Your block and paver choice from a supply yard; we order and deliver
- The patio size you want and whether you want steps down from the upper yard
- Where downspouts and a sump discharge currently empty
What JMB supplies
- Site measure of wall heights, the door sill and the fall of the yard
- Permit and engineered design arranged when the wall height calls for them
- Excavation of the slope, compacted base and block wing walls
- Drainage stone and drain tile behind each wall, run to an outlet
- Paver patio on a compacted base, sloped away from the door
- Channel drain or catch basin at the patio where the grade needs it
- Block steps from the upper yard if quoted
- Spoils hauled or spread, and photos in your job folder
How it is priced: per project
Quoted in writing from your photos within one business day. What moves the number:
- Height and length of each wing wall
- Whether the walls are tall enough to need a permit or an engineer
- Patio size and paver choice
- Drainage: where the outlet is and how far the pipe runs
- Steps down from the upper yard
- Access: machines around the house vs. hand work
- Removing an old timber or failed wall first
Send photos of the door, both sides of the slope and the yard below. A site measure sets the wall heights and the drainage plan.
How long it takes
Wing walls and a small patio at a walkout door: about one to two weeks, depending on wall height and drainage.
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
Straight wing walls
Walls running out from the house on each side of the door, stepping down with the grade to the patio.
Curved or tiered walls
Walls that curve out to the yard or split into two shorter tiers with a planting bed between, which can keep each wall under permit height.
Patio with a drain
A paver patio sloped off the door, with a channel drain or catch basin at the low edge where the yard is too flat to shed water.
Steps from the upper yard
Block steps built into one wing wall so you can walk down from the deck or the upper lawn to the patio.
Retaining Wall for Walkout Basement Patio — Wing Walls and Drainage: questions, answered
Why does water pool at my walkout basement door?
Because the door is the low spot. The hillside on each side drains toward it, and the patio is often flat or sloped toward the house. Regrading the patio away from the sill, adding drainage behind the walls and a drain at the patio edge moves the water away.
What kind of retaining wall is best for a walkout basement?
Segmental block walls are the most common: they step down with the grade, curve if needed, and have drainage built behind them. Boulders work where there is more room. What matters most is the base and the drain tile behind the wall.
Do I need a permit for a walkout basement retaining wall?
Often, when the wall is tall. Many cities require a permit and an engineered design above a certain height, and a wall near a foundation gets more attention. We measure the heights and check your city before quoting.
How do you drain a walkout basement patio?
Slope the patio away from the door sill, carry drain tile behind the wing walls to an outlet, and add a channel drain or catch basin at the patio edge if the yard is too flat. The pipes run to daylight, a pop-up emitter or a dry well.
Can you add steps down to a walkout patio?
Yes. Block steps can be built into one of the wing walls or run down the slope beside it, from the deck or the upper yard to the patio.
Can you replace an old timber wall at a walkout?
Yes. The rotted timbers come out, the slope is dug back, and a block wall goes in on a compacted base with drainage behind it. Timber walls at walkouts often fail because they had no drainage at all.
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 pavers pages
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