Commercial Concrete Floors for Boulder Valley Buildings

Flatiron Park's roughly 2.3 million rentable square feet, spread across more than 100 companies, include the kinds of buildings where a floor is a working surface, not a finish: lab benches, light assembly, storage and loading. A floor that curls at the joints or cracks across a bay is a daily annoyance to everyone who uses it. We place commercial slabs to flatness and levelness tolerances that match the use, and we treat the first three days after placement as seriously as the pour.

A slab starts below the concrete. We prepare the subgrade, set the base course, lay the vapor retarder where the finish or use calls for one, place reinforcing or fibers as specified, and lay out the joints before the first truck arrives. Finishing is done by a crew that has worked together on large placements, using laser screeds where the tolerances need them and power trowels for the final surface.

The owners who call us about floors are usually developers delivering shell space to tenants, logistics operators that will run forklifts over the slab for years, and facility managers repairing a floor that never worked quite right.

Floors for different kinds of use

A flex and light industrial building may need a moderate-load slab with good flatness for racking and a sealed finish. A food and beverage processing floor needs slope to drains, a dense surface and joints that resist washdown. A cold storage floor needs insulation and a heave protection system under the concrete. Each demands a different mix, joint plan and finishing method.

Longmont reports manufacturing as its largest industry at 7,188 people in its 2022 data, ahead of professional and technical services and retail trade. Making things and storing things puts heavy rolling loads on slabs, so we review the equipment list for point loads, wheel loads and any vibration-sensitive equipment before settling the slab design with the structural engineer.

From subgrade to sealed surface

We trim the subgrade to tolerance, proof-roll it and have it tested before base material goes down. Base is compacted in lifts and checked for grade. Edge forms, dowel baskets, keyways and isolation joints are set from the layout, and any embedded conduit or drains are installed and inspected before reinforcing. Then the pour starts, and the pour has to be organized so that every truck has a place to be and every finisher has a bay to work.

After the concrete is placed and finished, curing begins. We apply a curing compound or cover with wet burlap or plastic, depending on the specification, and saw the joints within the time window that prevents random cracking. Hardeners, sealers, polishing and coatings go on after the slab has dried enough to receive them, which is a conversation we begin well before the pour.

Why we plan the pour backwards

We plan a slab pour by starting with the finish and working backward. The finish determines the moisture and flatness the slab must reach, which determines the mix, which determines the placement window and the crew. In a dry climate with frequent wind, plastic shrinkage is a bigger risk than rain. Boulder gets Chinook winds that cause rapid winter warm-ups, and wind plus low humidity can pull water from fresh concrete in minutes, so we bring windbreaks, evaporation retarder and fog nozzles to the pour when the forecast calls for them.

Joint layout is the other piece of the plan. Joints are the place a slab is supposed to crack, so we locate them on the column lines and at re-entrant corners, and ask the structural engineer to approve changes. A joint plan drawn before the pour gives the finishing crew a map and gives the owner a surface that ages predictably.

Fitting floors into a building schedule

A floor wants a closed building, and the building wants a floor. We schedule slabs after the roof or enclosure is far enough along to keep weather off a fresh pour, and before racking, mezzanines and equipment arrive. In a warehouse construction project the slab pour often defines the critical path, so we split the building into placements that can run on consecutive days without cold joints in the wrong places.

Slab drying matters more than owners expect. Concrete may be strong in a week and still be too wet for a moisture sensitive coating, and testing is the only way to know. We run moisture tests on the schedule the flooring manufacturer specifies and tell the owner early when a coating date is at risk.

What changes the price of a slab

Thickness, reinforcement and flatness class set the base price. Joint type, hardener, polished finishes and floor drains add to it. Site logistics matter too: whether a pump can reach every bay, whether trucks can enter the building or must stay outside, and whether winter protection is needed. We price these separately so an owner can see what a flatter floor costs and decide whether the use justifies it.

Repair is the other budget item. A floor that curls, cracks or dusts can often be saved with cutting, patching, grinding or a topical treatment, but each route has limits. We tell the owner which defects are cosmetic and which are structural, and we price the repair path with a clear statement of what it will and will not fix.

Finishing that stays consistent

We keep the same finishing trade partner on slab work whenever the project allows, which keeps the same hands on the pour, the screed and the trowel. That continuity shows in the floor. We bring in specialty subs for polishing, grinding and coatings, and coordinate their schedules with the cure and moisture tests so that nobody is waiting on an unfinished substrate.

For floors in occupied buildings, we pair the work with tenant improvements teams so the demolition, trenching and patch-back are done by the same crew, and the new slab ties into the old one with correct dowels and joint alignment. A floor that matches the surroundings is the best sign the work was done well.

Describe how the floor will be used

Tell us about the loads, the equipment and the finish, and we will propose a slab design, a pour plan and a schedule that fit.

Questions Owners Ask

What flatness do we need?

It depends on the use. A storage floor with narrow aisles and tall racking needs tighter tolerances than a retail sales floor. The structural engineer or the equipment manufacturer should name a flatness and levelness requirement. We build the pour plan around it and measure the result after finishing, so the number in the specification becomes a number in the field.

Why do slabs curl and crack?

Concrete shrinks as it dries, and a slab that dries faster on top than on the bottom curls at its edges and joints. Poor joint spacing, rapid drying in wind and thin base preparation make it worse. We control it with joint layout, curing, evaporation control and a mix suited to the placement conditions.

Can we pour a floor in winter?

Yes, if the building is enclosed and heated, or if the slab is protected with blankets and heated enclosures. Cold concrete gains strength slowly, and finishing during a cold snap can trap bleed water. We plan the placement with the weather and add cold-weather measures to the budget when needed.

How soon can we install flooring or coatings?

Only after the slab has dried enough for the product. We test moisture using the method the manufacturer specifies and report the results, and we start the testing early so the answer arrives before the schedule needs it.

Is polished concrete a good option for a lab or light industrial space?

It can be durable and easy to clean when the slab is placed and finished with that result in mind. The mix, the finishing method and the joint plan need to be set before the pour, not afterward. We discuss the use, the cleaning methods and the budget before recommending it.

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