The demand for low-cost, moisture resistant and waterproof flooring continues to grow at a rapid pace, and for good reason—with the right approach, the results are durable, low maintenance and long-lasting. Although the focus tends to be on cost per square foot and the flooring material itself, following strategic steps before the flooring goes in will save you from expensive repairs down the road. While the right system may cost a little more initially for many multi-family projects such as hotels, college dorms and apartments, it will provide significant savings when it comes time to replace flooring. Over the course of my career, I have seen more than my fair share of moisture-related flooring disasters in both commercial and multi-family spaces. My hope is that the information I cover below will help protect your investment and your sanity. 

Map Out Your Priorities 

Your focus may be on installing flooring that is affordable and moisture resistant or waterproof. You may also have your sights set on choosing environmentally friendly materials with low-VOC finishes and sealants. I recommend thinking in terms of the total cost of ownership and return on investment. With all of this in mind, we must look underneath the flooring surface.

What Makes a Flooring Material Waterproof? 

Before we jump into waterproofing specifics, it’s important to note that while waterproof flooring material is non-permeable by definition, it takes more than the right material to ensure overall waterproofing success. Even when the flooring itself includes some form of plasticizer or PVC, it won’t protect entirely against bottom-up issues with moisture. The reason for this is the ever-changing pH emitted by the concrete beneath. A high pH or alkaline scenario often results in cupping, doming or the loss of dimensional stability in the flooring. Kendall Youngworth for Buildings.com reports: “Concrete is porous by nature and, even though the moisture near the surface of the concrete evaporates as it cures, moisture from below the concrete or within the concrete will tend to osmotically migrate up through the concrete capillaries, to escape through the path of least resistance.”

RH Balance Is a Must

For flooring to be successful long-term, you must establish and maintain an equilibrium or RH balance in the slab. This balance is key since it directly impacts the substrate emissions rate. Just as your body perspires to control your temperature (leaving salts behind), concrete responds to its environment by emitting vapor and carrying salts. The result is often a high pH water mixture that can wreak havoc on waterproof or moisture-resistant floors.

Dangers of Moisture Damage

Excessive moisture vapor transmission can result in a host of flooring issues. Beyond reducing the lifespan of materials and a possible deterioration of the concrete substrate, Youngworth also cautions against uneven walking surfaces linked to slip-and-fall hazards, an invalidation of the flooring warranty and the “development of mold or pathogen growth either on top of the concrete slab or beneath the flooring material.” These problems don’t even begin to cover the headache of addressing the root cause and making costly repairs.

Analyze Your Environment to Spot Potential Moisture Issues

Before shopping for the best flooring for your dollar, study the project environment. A thorough site inspection for moisture issues is critical. Especially when remodeling, moisture testing should include specifics on the condition of the concrete, amount of water, RH levels, pH and and moisture vapor emissions rates. 

Are you dealing with a structure that is prefab concrete or stick built? One given: when concrete is sitting in the dirt, without a moisture retarder water can migrate up, leading to moisture issues in the bottom floors. Upper floors have their own set of challenges with water, though typically those are related to leaks. In new multi-family builds, you have more control over creating the ideal environment before breaking ground.  

Design a Worry-Free System

Proactively plan to avoid “concrete defeat.” For new construction projects, look for a moisture mitigation system that can be applied to concrete within 12 hours after it’s poured (provided it’s porous) that will do three things:

• Help the concrete to stay healthy by keeping moisture in during the curing process
• Serve as a waterproofer so external moisture doesn’t affect the concrete
• Create an internal  vapor barrier (in the concrete) where water vapor doesn’t come out and affect your flooring 

For remodels, be aware that anything built prior to 1980 means there was either no vapor retarder in place or it’s been compromised over time. No matter when the property was constructed, you’ll want to have a detailed moisture analysis performed on the concrete. That analysis should include what the concrete is doing, where the moisture is coming from and where the water is going. Look for moisture mitigation products that can be applied one time to prevent further issues as new flooring is installed or reinstalled. Additionally, ensure you meet installation standards, which vary by flooring material. The Carpet and Rug Institute publishes a gold standard that outlines best practices. Flooring manufacturers also provide installation specifics. 

Lock It in With an End-To-End Warranty

Should an issue arise, the last thing you want is finger-pointing. Insist on an end-to-end warranty or you’ll risk multiple companies shifting the blame. Think about your finished project like a five-layer cake. If there’s an issue with the middle layer in the cake, which other layers were involved in the reason the cake failed? The result can be a legal drain, a time drain and one that impacts the total cost of ownership. Once you have found the right warranty, protect your investment by carefully following its requirements.