Identifying and fixing concrete flooring challenges

by arslan_ahmed | September 6, 2023 5:03 pm

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By Emily Newton

Concrete floors are popular choices in certain spaces in a variety of finishes as they are long-lasting and extremely durable if the contractor has installed, cured, and finished them properly. However, issues can arise during or after installation, and construction professionals must know how to diagnose and fix these concrete flooring challenges.

This article outlines some crucial steps the construction professional may take on behalf of the owner when addressing challenges as to slab-on-grade concrete floors, including those with polished or broom finishes. Although most relate to concrete floors installed indoors—in residential and commercial buildings—some tips mentioned also apply to outdoor installations.

Determining the issues and causes

A good start in the professional’s troubleshooting process is to discern the following questions with the owner on-site:

• When did the issues start and have any activities caused them to worsen over time? Have environmental factors, such as products for cleaning and deicing, harmed the concrete? Has frequent traffic from heavy vehicles, such as forklifts, damaged the concrete? If the concrete flooring is in a protected area, such as a garage, have pedestrians tracked products such as deicing salts onto it?
• Are there specific areas where the concrete floor has started to bulge or push up due to possible soil upheaval following heavy rainstorms and water build-up and pressure under the concrete? Did temperatures drop below the freezing point soon after installation?
• Are there cracks in the concrete flooring? Did they occur after a sudden impact? What hit the floor and when did the impact occur? Did the cracks appear because of installation mistakes, such as too much water in the mix, or selection of the wrong strength of concrete to pour?
• Did the concrete slab design include reinforcement to compensate for shrinkage to address the possibility of cracking?¹ Did cracks arise due to issues associated with how well the contractor cured the floor in the first few critical days to help ensure the concrete did reach its full strength in or after 56 days after installation?

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It is not always easy to pinpoint the root causes of problems with concrete flooring, but construction professionals must strive to determine what went wrong, because it can minimize the chances of repeat problems in the future.

Fixing concrete flooring challenges

Some construction professionals engage owners who assume they have relatively minor concrete floor issues—those owners may even wonder if they need to address the issues at all. This situation could also occur if an owner believes the problem is merely a cosmetic one.

However, it is up to the professional providing construction services and advice to help owners gain a broader perspective and advise them the problem could get worse if they do not act quickly.

For example, consider a concrete-related moisture problem. Concrete still contains moisture once it has fully cured.² One can measure the relative humidity (RH) or the rate the moisture vapor moves through the concrete surface to determine if the material is too damp. Manufacturer guidance typically details which test methods to use and the acceptable moisture vapor transmission limits.

Various complications can result if tests indicate there is a concrete moisture problem and decides to wait to fix it. The substrate can eventually deteriorate, or cracks can start to appear in the floor coating. The concrete surface can also become uneven, creating safety hazards in heavily used areas of a building. Some consequences are harder to see, including mold or pathogen growth beneath the surface of the floor.

The main point to get across to any owner in this position is this: it is better to act promptly instead of hoping the problem will not worsen. Even if the situation seems stable to the owner, it could be an incorrect assumption as not all complications are immediately visible.

Discussing replacements and repairs

Once the professional has determined the specific problem and its scope, it is important to discuss whether the best approach is to replace or repair the affected area. Replacement can be more expensive, but the overall cost may be worth it if the issue is extensive or if the owner wants to make more-extensive improvements to the area.

For example, research indicates more than one-third of office-based employees do not have enough light in their workspaces.³ However, replacing faulty flooring with polished concrete can make a space brighter and more inviting.

Repairs can solve many concrete flooring challenges, particularly if owners notice something amiss and contact a professional quickly. For example, some cracks appear with one side noticeably higher than the other. Uneven settling beneath the concrete’s base layer may cause this problem.⁴ However, injecting slurry or foam under the slab can sometimes remedy the problem.

If the concrete flooring challenges are too extensive to warrant successful repairs, a replacement will likely be the desired outcome. Discussions should take place regarding all the necessary particulars of that route, including recycling the removed material or reusing the removed material on the property.

Clarify needs and expectations

Once the concrete flooring challenges are identified, it is time to talk about the specifics. For example, what is the budget, and are there financing options to make the costs more manageable? What steps can one take to solve the issue, and what is the project’s overall time frame?

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Construction professionals should indicate to the owner that a contractor can fix a moisture issue by placing a vapor retarder between the ground and concrete slab, particularly indoors. Although 6-mil poly was the standard choice for many years, it is now common to put a 10-mil barrier under parking-level slabs and increase that to 15- or 20-mil for habitable spaces. In addition, designers often recommend a fully waterproof membrane when moisture is under the slab. However, if the owner still sees evidence of moisture after the fix, it does not necessarily mean the retarder failed. Humid conditions can also cause wetness on concrete flooring when warm air condenses into colder surfaces.

Owners will appreciate knowing how long it will take to fix the concrete floors, especially if the affected area plays a significant role in their business operations. What amount of time must pass for the floor to cure properly and reduce the chances of complications later?

Construction professionals must bring up matters that may require the owner to change how it maintains or uses the concrete floors. Does the owner need to use different cleaning products or stop parking vehicles, such as semitrucks, on the concrete for extended periods? The more the owner knows before the repair or replacement occurs, the better position it will be in to ensure the restored floor’s longevity.

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Taking a thorough approach

Whether professionals need to tackle challenges that occurred soon after installation or years later, they should always do so with a careful approach to investigate the issue and determine the root causes before planning the fix. However, it is also wise to take steps to prevent future problems with concrete floors.

To control possible issues before the contractor pours the slab, engineers must evaluate site preparation, soil compaction, and bearing strength and then slab thickness reinforcement measures, control joints—as to mitigation of temperature-related cracking—and building use.

Construction professionals must encourage owners to maintain quality control (QC) and hire those with the experience necessary to pour, finish, and cure the flooring and require them to have completed ongoing training. Construction professionals must be more specific in conversations with owners about those aspects that can make concrete floors fail after installation.

Keep in mind, the process for fixing current concrete flooring challenges and mitigating future ones can directly impact a company or professional’s reputation—which is why it is best to cover all the bases and help owners know what to specify and what to expect.

Notes

¹ Read more about best practices for installing concrete floors, www.nfca.ca/free-resources/concrete-specification/[5].

² See moisture issues in concrete floors,
www.buildings.com/sealants-coatings/article/ 10185704/signs-a-concrete-floor-has-moisture-issues[6].

³ For more information, read the benefits of polished concrete floors, www.dcpu1.com/blog/benefits-of-polished-concrete-floors/[7].

⁴ Learn how to repair cracks in concrete floors,
www.thespruce.com/how-to-repair-concrete-floors-1398172[8].

Author

Emily Newton is the editor-in-chief of Revolutionized Magazine She has more than six years of experience writing industrial topics for the construction, manufacturing, and supply chain industries.

Source URL: https://www.constructionspecifier.com/identifying-and-fixing-concrete-flooring-challenges/

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