Elements of Engineering a Damn Good Industrial Floor (Part 2)

The basics of industrial concrete flooring design specification and construction.

Industrial flooring experts know the importance of understanding typical design requirements laid out in the contract documents of a job. When the drawings and specifications state clearly what is required, flooring projects tend to progress to the intended outcome more smoothly. Making sure that specifications are on point and include no conflicting provisions is the central purpose of pre-installation meetings between the industrial flooring expert, designers and facility owners. When these guys get together, here’s what specifications they’re going to discuss:

• Base and subbase materials – pin down requirements for preparation and location of a vapor retarder, if applicable
• Concrete thickness – one of the primary decisions, thickness is based on the subbase, anticipated loads and minimum concrete compressive strength, flexural strength or both
• Job-site chemistry – concrete mixture proportion requirements such as materials, water-cementitious materials ratio (w/cm), slump and allowable admixtures
• Reinforcement – the location and type, including position of reinforcement during construction
• Surface treatment – hardeners for more durable surfaces, if required
• Surface finish – typically hard troweled for industrial flooring, except in the case of air entrained concrete, when hard troweling can lead to delaminated surfaces
• Tolerances – for subbase, slab thickness and surface finish including FF and FL requirements; many refer to ACI 117, Standard Specification for Tolerances for Concrete Construction and Materials for specifications
• Concrete curing – requirements for hot or cold weather response
• Joint filling material and installation techniques – confirm requirements

Quality assurance and control – that’s what pre-installation meetings can solve, especially when it comes to more complex floors. Documenting compliance with the specification can also be a critical component of the process.

To help with these design requirements, flooring and constructions experts refer to the recently updated ACI 302.1R-15 Guide to Concrete Floor and Slab Construction and its complement, the ACI 360R-10, Design of Slabs on Ground –both available from the American Concrete Institute (ACI).

Tips on Industrial Floor Construction

• The following are common techniques for installing industrial floors:
• High tolerance, superflat industrial floors are typically placed in long alternating strips.
• Setting the side forms and screeding impact floor levelness and surface elevation.
• For level F-min floor requirements, the side forms are set, checked with surveyor’s instruments and planed to precise elevations.
• Wide bull floats attached to trowel blades increase floor flatness.
• Strike-off or screeding with a laser screed allows concrete to be placed and leveled without side forms.
• For higher tolerance floors, follow up the initial strike-off with an 8- to 10-foot wide bullfloat or a highway straightedge, which can increase flatness by 50%.
• Pans slipped onto the blades of a power trowel greatly increase flatness.
• Walk-behind or a ride-on trowels greatly speed up the finishing operation by compacting the surface to provide a dense, hard, smooth layer; a subsequent trowel pass should be perpendicular to the previous pass
• Wet curing with curing covers is critical to a strong surface.
• If the slab surface dries out, the concrete will lose strength and develop plastic shrinkage cracks. Proper curing time and procedure is critical.

About Surface Solutions

Recognized as a top UCRETE® Master Contractor since 2012, Surface Solutions is an independent industrial floor contractor specializing in seamless, polymer flooring systems utilizing the most trusted brands in the industry. From testing to consultation and complete installation services, Surface Solutions is your premier source of non-toxic, safe and environmentally friendly flooring systems, offering turnkey installations using only in-house personnel. All installations come with a complete single-source warranty.

Photo: Filip Krstic / Shutterstock.com

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