The edge of a parking lot is more than a boundary. It's the drainage system that moves water off the slab and into catch basins, the barrier that keeps vehicles from rolling onto landscaping, and the detail that ties your lot to the public street. Portland Concrete builds both ways: machine-slipformed for long continuous runs and hand-formed for transitions, drop-curbs, and curves. Free written estimate included.
A gutter without slope is a trough that collects standing water. The pan must pitch toward catch basins at a grade steep enough to move water during peak runoff, yet shallow enough that the curb height stays within code. We set slope at staking, monitor it as the slipform machine moves, and verify it after the concrete cures so you know water will actually drain.
Long straight runs get machine-slipformed because the equipment maintains consistent cross-section and slope faster than hand work. Where the lot has corners, intersections, or ADA-compliant drop-curbs, we switch to hand-forming and tie the sections together seamlessly. The result is one continuous drainage system, not a patchwork of techniques.
The curb centerline is marked from the property survey and drainage plan. Elevations are set at every catch basin, transition, and slope change. This staking is the foundation for everything that follows.
Excavate and compact base
Subgrade is cut to depth, compacted, and gravel base is placed and compacted again. The surface is brought to the exact elevation where the curb concrete will start, so the pour sits on a stable, level foundation.
Form and pour the concrete
Long runs use a slipform paver that extrudes the curb and gutter profile in one pass. Transitions and curves are hand-formed with screeds and floats, then tied into the slipform sections with matching cross-sections.
Joint, cure, and finish
Control joints are cut at engineered spacing to manage shrinkage. The concrete cures protected from rain and sun. Tie-ins to the adjacent parking lot slab and street pavement are detailed so the meeting line is clean and functional.
Common failure point
Why Drainage Slope Fails in Winter
A slipform machine that loses elevation by even a quarter-inch per hundred feet creates low spots where water pools. In Portland winters, those pools freeze and thaw repeatedly, cracking the concrete and backing water into the lot. We monitor slope continuously during the pour and verify it after cure with a level and straightedge, confirming the water path to each basin actually works.
Curb also has to meet the adjacent lot slab flush, so water doesn't pond at the joint. It has to tie into the city street at the right elevation if the project includes a public connection. And it has to accommodate any ADA ramp or curb-cut detail without creating a trip hazard. These are not afterthoughts; they're part of the design from staking. Our broader parking services coordinate all of these details.
Slipform vs hand-formed, slope verification, city tie-ins, and repair options.
Both, depending on the run. Long continuous runs are slipformed for speed and consistency; transitions, intersections, drop-curbs and curves are hand-formed where the machine cannot work. Most lots get both techniques in the same project.
Surveyed at staking, monitored during the pour (slipform machines lose slope if they catch on irregularities), and verified after cure. A pan without slope holds water; we never leave one without confirming the drainage path actually works.
Yes, where the project includes a city tie-in, the curb is poured to the city's spec at that transition. We coordinate with the engineer and city inspector on the elevation and cross-section so the tie-in passes inspection.
Yes, isolated sections of failed curb can be cut out and re-poured to match. See parking lot repair for that triage approach; we treat curb damage the same way.
Machine slipform moves quickly; a long lot perimeter can be done in a few days. Hand-formed transitions add time; the full schedule is in the quote so you know how long curb work takes within the larger project.
Client reviews
What Portland Operations Say About Their Curb & Gutter
Long slipform run around our entire lot perimeter. Continuous, sharp edges, exact slope to the catch basins. The drainage works perfectly through every melt.
W. N.
Property Manager, Portland
★★★★★
Hand-formed transitions at every entrance look like part of the design, not patched-in. They coordinated the curb pour with the asphalt apron so the meeting line is invisible.
Q. L.
Retail Plaza Owner, Vancouver
★★★★★
City tie-in passed inspection first time. They knew the city's spec, poured to it, and the inspector signed off without revisions. Saved real schedule slip.
Z. L.
Industrial Site Manager, Hillsboro
★★★★★
Drop-curbs at every accessible ramp tied in flush. ADA inspector confirmed compliance. The detail work shows; nothing improvised, everything to spec.
Y. E.
Mall Operations, Gresham
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