Patios & Hardscape in Lakewood, Colorado

Lakewood's retaining wall rule is not the one you think

Almost every jurisdiction on the Front Range exempts retaining walls under 4 feet. Lakewood exempts them under 30 inches — measured from grade to the top of the wall, not from the bottom of the footing — and the exemption goes away entirely if the wall supports a surcharge.

Read that again, because it's the single most consequential local fact on this page. A 3-foot wall is permit-exempt in Golden and Arvada. In Lakewood it requires a permit. A crew working "4 feet everywhere" from muscle memory will build you an unpermitted wall in this city.

We check it. Every time. And a "surcharge" is not an exotic condition — a patio, a driveway, a slab, or a regularly parked vehicle sitting above a wall is a surcharge, and it kills the exemption at any height.

The ground

Lakewood straddles the transition where the Denver Formation gives way to Pierre Shale — Cretaceous marine clay-shale carrying bentonite beds. The Colorado Geological Survey documents smectite clays swelling up to 20 percent by volume and exerting forces up to 30,000 pounds per square foot when they take on water. That is not a number a patio argues with. That is a number a patio drains away from.

The character changes as you move across the city:

• East Lakewood, toward Denver: claystone bedrock, expansive soils, standard metro conditions.
• Along Bear Creek and the gulches: alluvial sand, gravel, and cobble. Better draining, harder digging.
• West, toward Green Mountain and the Hogback: real grade, shallower and steeper-dipping bedrock, and a lot more rock in the hole. Also more walls, more steps, and more drainage design.

Frost and base

Lakewood's adopted design criteria list a 36-inch frost depth, a Severe weathering classification, and a 1°F winter design temperature. That's the climate your base has to live in.

So: excavate to the full section, 8 inches of compacted Class 6 on the clay side of town, geotextile between the clay and the aggregate, 3-to-4-inch lifts, every lift compacted, and about ¼ inch per foot of fall away from the house. Behind any wall: 12-plus inches of clean drain rock and a perforated pipe that actually daylights.

That spec is the whole job. Here's the version you can hold any contractor to.

What we build here

Paver patios and dry-laid flagstone on the clay, because a flexible pavement can be repaired when the ground moves. Retaining and seat walls on the west-side grade — permitted, drained, and engineered where the height calls for it. Concrete flatwork where a flat, shovelable slab is the right answer.