A concrete walk in the Denver metro lasts when it's built on compacted soil and a gravel base, sloped so snowmelt sheds off, jointed at regular intervals, and poured with an air-entrained mix. Swelling clay, settling backfill and tree roots are common causes of trip hazards. Public sidewalks are in the right-of-way, where city rules and licensed contractors apply.
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Walkways and sidewalks are thin, narrow slabs, which makes them the first concrete around a Denver home to show soil movement. A heaved panel by the front steps, a sunken section where the downspout empties, or an edge lifted by a street tree are some of the most common requests we see. They're also trip hazards, which makes them worth fixing sooner rather than later.
Common walkway projects
- New front walks from the driveway, street or alley to the door
- Side-yard paths to a gate, trash area or detached garage
- Replacing heaved, sunken or flaking panels
- Concrete steps and landings on sloped lots
- Widening a walk for strollers, wheelchairs or walkers
Building a walk that stays put
Like any slab, a walk depends on what's under it. The subgrade is compacted, a gravel base is placed, and the walk is poured with a slight cross-slope so water and snowmelt shed off instead of ponding and freezing. Control joints are tooled at regular intervals, and isolation joints separate the walk from steps, the house and the driveway so each can move on its own. Walks along the foundation sit on backfill and in the zone where roof runoff and sprinklers wet the clay, so drainage there matters most.
Freeze-thaw and deicers
Front walks get the most shoveling and the most ice melt. Repeated freezing and thawing, combined with deicing chemicals, can cause scaling, where the top layer flakes off. Air-entrained concrete, a properly finished surface and good curing all help. Keep deicers off new concrete during its first winter, use sand for traction, and if you use a deicer later, follow the product label and avoid piling it on.
Steps
Steps need consistent riser heights and tread depths. Steps attached to the house, or that serve as a required exit, can fall under building code rules, including handrails above a certain number of risers. Requirements vary by city, so ask your contractor whether a permit is needed.
Public sidewalks in Denver and nearby
The sidewalk along the street is normally in the public right-of-way. In the City and County of Denver, the Department of Transportation and Infrastructure runs a Sidewalk Program that repairs sidewalks and bills property owners under its own rules, and work in the public way requires a city right-of-way contractor license. Some older Denver neighborhoods still have historic sandstone flagstone sidewalks, which can carry their own repair considerations. Arvada issues right-of-way permits only to contractors holding its Municipal General Contractor license, and other cities have similar registration rules. Before replacing any public sidewalk, check with your city's public works or transportation department about responsibility, permits and specifications.
Repair or replace?
- Hairline cracks are usually cosmetic.
- Sunken panels that are still intact can often be lifted. See concrete repair and leveling.
- Heaved, broken or badly scaled panels are usually replaced from joint to joint.
Questions to ask
- What base and thickness will you use, and how will the walk drain?
- How will you handle tree roots near the walk?
- Is the mix air-entrained, and how will you cure it?
- Does this work need a right-of-way permit, and are you licensed for it in my city?
Have a trip hazard or a new path in mind? Request a walkway contractor and include photos.
See how it works
Frequently asked questions
Who fixes the public sidewalk in front of my Denver home?
In the City and County of Denver, the Department of Transportation and Infrastructure runs a Sidewalk Program that repairs sidewalks and bills property owners under its rules. Other cities handle it differently. Check with your city before repairing a public sidewalk yourself.
Why is my front walk flaking?
Surface flaking, called scaling, is common in Denver where freeze-thaw cycles and deicing chemicals attack concrete that wasn't air-entrained, was finished poorly or got salt in its first winter. Resurfacing can help if the slab is otherwise sound.
Can a heaved walk panel be pushed back down?
Usually not. Lifting works on panels that sank. A panel pushed up by swelling soil is typically ground down if the lip is small, or removed and replaced after the water source is fixed.
Sources and further reading
- Colorado Geological Survey: expansive soil
- Colorado Geological Survey: heaving bedrock hazards, Douglas County (SP-42)
- CSU Extension PlantTalk: expansive soils
- Jefferson County: geology and dipping bedrock
- City and County of Denver: right-of-way contractor licenses
- Denver DOTI: sidewalk repair and construction
- City of Aurora municipal code: work in the public right-of-way
- City of Lakewood: contractor registration
- City of Arvada: right-of-way permits
- Town of Castle Rock: right-of-way permit information
- Highlands Ranch Community Association: covenants and improvements
- Denver Water: summer watering rules
- Colorado 811: homeowners
- American Concrete Institute (ACI)
- Portland Cement Association (PCA)