The Pros and Cons of Concrete Floors
Humans have long utilized the strength and performance of concrete to support their grandest structural creations. Ironically, both ancient Egyptians and Romans encountered exactly the same fundamental challenges facing today’s concrete builders and homeowners. We have come a long way in recent years, but concrete’s success is still built on fundamentals.
In the 21st Century, concrete mixing and setting technology has spawned exciting new styling options for concrete floors. These include stamping, stains, patterns, colors and textures, along with traditional floor coverings. From stylized concrete mixtures to designer walls, concrete has become a primary “go-to” building material. While it’s tempting to focus only on concrete’s abundant creative opportunities, paying attention to the basics remains critically important.
Egyptians established the first known concrete slabs in approximately 2500 BC, mostly likely for many of the same reasons people choose concrete today. Presumably, they wanted them to last. Three additional reasons—durability, maintenance and versatility—make concrete a popular choice today as well.
A fully-sealed and well-maintained concrete slab can last indefinitely.
Obviously, this characteristic resonates positively for anyone who prefers a one-time capital investment in the floor. And for the aesthetically inclined person, it’s reassuring to know that artistic elements incorporated into the concrete structure can be equally preserved.
The domed roof of the Roman Pantheon is a great example of concrete’s durability. The Romans used lightweight aggregates for the roof, which today remains the largest dome in the world comprised of unreinforced solid concrete. The Pantheon stands as a testament to concrete’s ability to withstand whatever nature dishes out over the centuries.
Protective concrete surfaces need only be sealed or waxed every few months in high-traffic areas, depending on the concrete mixture. Some seals provide such wear resistance that the slab may just need basic cleaning and sweeping.
Despite the advantages, concrete floors do have some potential drawbacks. Concrete is not exactly “warm” by definition and it can easily develop small cracks or other difficulties as either the surrounding structure or the ground underneath shifts. But the big downside to concrete floors is that when things go wrong, they are costly to repair.
Moisture is a major factor in a lot of flooring failures, and one that will typically escape the attention of many consumers until the damage has been done. Most builders know about the importance of concrete moisture and how the moisture condition changes as slabs harden and hydrate to their specified compressive performance characteristics.
They also know that all concrete is never truly dry. There’s always a certain amount of water in a concrete slab. This means floor covering installers must test for concrete moisture to verify that the slab’s moisture condition is appropriate for the specific flooring application.
Perhaps the ancients would have been drawn to the modern concrete moisture meter, a useful tool for assessing moisture condition at the surface. A concrete moisture meter can help identify areas of excess moisture where a serious flooring problem might easily develop.
Modern-day science, however, tells us that surface measurements don’t give the whole story, or even the most important story. Vital information is lacking about what is going on inside the slab. Typically, after the slab is poured and during the drying process, a moisture gradient exists such that moisture levels can be significantly greater deep down in the slab. This fact guarantees huge headaches later if a flooring installation is performed too soon, when moisture levels deep within the slab remain high.
Ambient relative humidity is another variable affecting the reliability of surface measurements. Moisture evaporation rates will fluctuate with the relative humidity (RH) surrounding the slab, thus slowing or accelerating the natural drying process.
From the moment of pour to the moment of truth, moisture rises from the bottom of the slab and evaporates at the surface. Adequate time is needed for this moisture migration. Bottom line: It is crucial to assess the slab’s internal moisture condition before proceeding with a floor covering installation.
Wagner Meters has developed a state-of-the-art test method for assessing overall slab moisture condition from the inside: the scientifically proven Rapid RH® system. Using either the Wagner Meters Rapid RH® 4.0 EX or the Rapid RH® 5.0 will measure the concrete moisture at a depth of 40 percent below the slab’s surface (when drying from one side).
At this depth, science has clearly shown that in-situ probes provide RH measurements that accurately and reliably gauge the overall moisture condition of the concrete slab. By using either Rapid RH® system available from Wagner Meters, general contractors and flooring installers will be armed with the best possible information for deciding when to move forward with their building project.
Pay proper attention to the concrete core, and the rest builds upon its integrity.