5 Common Mistakes Many People Make When Choosing Flooring After Water Damage!

Do you own an older home built with a slab-on-grade foundation in the the 1960s or 1970s? If so, there’s a high probability that your floor has moisture problems due to water damage. Homes built during this period typically lack insulation beneath the concrete, which causes moisture from the ground to seep upward through the concrete floor. Many customers we meet struggle to make the right decision about which flooring to install after moisture damage. Here, we list the 5 most common mistakes people make when choosing new flooring after experiencing moisture damage.

Understanding the cause of moisture damage is crucial to making the right choice for a new floor.

1. Self-leveling compound on an old concrete slab

If you own a house with an old concrete slab, we recommend against applying a self-leveling compound on top of it. This is because older concrete slabs are often not insulated from below, and if you apply a self-leveling compound on top of an uninsulated concrete floor, there is a high risk of later experiencing moisture damage from below. The space becomes too airtight, and moisture from the ground pushes upward and passes through the concrete slab, where it causes moisture problems when the temperature is cooler than indoors.

Unfortunately, trying to apply a self-leveling floor over installed underfloor heating is not a good option either. Since the underfloor heating beneath the concrete slab, combined with the high temperature of the soil, allows the soil to retain higher moisture levels. When the underfloor heating is turned off during the summer, this causes even more moisture to seep up through the concrete. This effect has been tested and documented and is commonly referred to as the “heat cushion” effect.

To avoid and prevent moisture problems, we recommend using a mechanically ventilated floor that creates an air gap between the floor and the subfloor and then distributes the airflow through air ducts. This keeps the concrete slab dry and free of moisture. 

2. Uses passive ventilation

Another common mistake is to raise the floor or lay a spacer mat without using mechanical ventilation. Simply raising the floor after moisture damage does not help, since the problem still remains. In any case, moisture will seep through the concrete slab and create problems that, in turn, lead to microbial growth that produces odors and can spread airborne particles through the air gap. 

3. Floating Floors

Another common problem is the decision to install construction sheeting and hardwood flooring with or without cellular plastic. This, too, results in microbial growth beneath the weather-resistant plastic.

4. Bad odors will not go away until the moisture damage has been repaired

When you have a moisture problem in the floor, you fix it by tearing out the entire floor down to the concrete slab. After this work is done, customers often notice that the musty, stuffy basement odor has disappeared. The odor disappears temporarily because the concrete slab is exposed, and a fan helps dry out the moisture damage. Many people then make the major mistake we mentioned earlier in this article: either applying a self-leveling compound or installing joists without mechanical ventilation. The problem is that the moisture returns when the structure is sealed and the floor has not been properly ventilated. 

5. Simply drying out water damage is not enough

In some cases, simply drying out moisture damage is not enough, which is a very complicated issue for many contractors who deal with moisture damage. Once moisture damage has occurred, the moisture content in the concrete slab is determined through a measurement. Next, moisture damage remediation is performed, which involves setting up fans to remove ground moisture. Problems arise, however, when the fans are later removed to install flooring; the ground moisture then returns and causes complications. We recommend conducting a moisture measurement to check for ground moisture even in areas where moisture damage has not yet occurred. This provides a better understanding of the specific construction you are working with. 

To avoid moisture problems, we recommend using mechanically ventilated floors. A raised floor with practical ventilation solutions gives you full control over the floor. We create an air gap between the floor and the subfloor, which then distributes the airflow through air ducts. Contact us, and we’d be happy to tell you more!