Parker Exposed Aggregate Concrete

Here's the phone call we get most: somebody has swept a coffee can of loose pea gravel off their front walk three springs running, and they're done pretending it's normal. It isn't. A washed surface should hold its stone for decades. When rock collects at the low end of a drive or rattles under a shovel, the paste gripping those stones has quit, and sweeping changes nothing.

We pour new exposed aggregate around Parker and we diagnose the old. The finish is simple in concept: place the concrete, hold back the top layer of cement paste, wash it off at exactly the right hour so stone stands proud without falling out. Simple in concept. Unforgiving in practice, which is why so much of it fails early and why the failures show from the sidewalk.

What the surface is telling you

Why stone lets go in the first place

Every washed surface is a bargain. Expose too little and you get a gritty gray slab that never shows the rock you paid for. Too much and the stones sit perched instead of embedded. That second mistake becomes loose gravel five winters later. Water gets into the gap under a perched stone, freezes, and pops it. A few hundred cycles a season and the surface unravels from the top down.

Air entrainment matters more here than on plain flatwork, because a washed finish has enormous surface area and every bit of it gets wet and frozen. We won't place one without a proper exterior mix. We also watch what the slab sits on. A washed patio over soft ground cracks like anything else, and that crack always seems to find the prettiest part of the field.

The washing season on the Front Range

Late April through mid-October, with September and early October at the top of the list. Cooler afternoons stretch the working time, the air is drier, and the slab still gets weeks of mild weather before anything freezes. Midsummer pours happen constantly; we start at daybreak and beat the heat to the wash.

Winter is a different conversation. We pour cold-weather flatwork with heated mix water, non-chloride accelerators, and blankets, but a washed finish needs an open, wet, uncovered surface at exactly the wrong moment for a January morning. So we book winter calls for spring and spend the cold months on estimates and stone selection. No deicer touches new washed work its first winter. Sand, a plastic-edged shovel, and let the sun do the rest.

Stone choice, and where this finish fits around town

The rock decides the look, so we start there. Rounded river gravel gives warm browns and tans and stays comfortable underfoot. Crushed granite reads cooler and sharper, with more sparkle in low sun. Bigger stone means bolder texture and harder grip; smaller stone is kinder to bare feet near a hot tub. Bring us a handful of what you like and we'll match it or tell you we can't.

Out in The Pinery and on the wooded acreage lots, this is our first recommendation for shaded walks, since a north-side path that never fully dries needs texture more than it needs looks. In Canterberry Crossing and Clarke Farms it shows up as a border or apron against plain gray. In Reata we're usually adding it out back where the builder left bare dirt.

How we run a washed pour

• Subgrade cut, road base compacted, forms set to the grade water has to follow
• Steel sized to the use and chaired up so it lands mid-slab, not on the dirt
• Air-entrained exterior mix, stone gradation confirmed with the plant before loading
• Retarder sprayed evenly right after finishing, then the slab covered
• Somebody watches the set the whole time; wash timing beats every other call on the job
• Wash and brush together, the whole field at one depth, so there are no light patches
• Rinse water contained, beds and siding shielded, sealer once the slab is dry