High moisture levels are a billion-dollar problem for the construction industry, and flooring is particularly affected. Changes in construction processes, materials used, and accelerated build schedules compound to create one colossal moisture problem.
On new construction and renovation projects alike, the amount invested in dedicated moisture mitigation products has rocketed. However, not all flooring products are created equal: some products mitigate the risk of moisture problems, while others serve to cover-up the issue.
Before paying out for expensive moisture mitigation products, we've identified five questions to ask your flooring installer or supplier, to determine the best solution to mitigate the risk of moisture problems on your project.
1) What are the Relative Humidity (RH) Limits on Your Chosen Flooring and Adhesive?
It's important to know the RH limits of your selected flooring products, as this will impact the type of moisture mitigation solution required. However, it's important to realize that the RH levels measured on site are just a snapshot of that moment and that specific place.
Many subfloors incorporate some type of vapor retarder, but if it's compromised in even a single area, RH levels can vary hugely across the installation site. So while your chosen flooring may meet the RH limits at that point, the moisture levels in the subfloor may change over time (due to fluctuations in the water table, for example) and push you outside of those limits in years to come.
2) What are the pH Limits of Your Adhesive?
Many standard adhesives are able to withstand up to 9 pH.
The natural pH range of cement is 11-13, but once it's poured and starts to dry, it reacts with the carbon dioxide in the air and forms a layer of calcium carbonate on top - which has a pH of 9. However, if liquid water forms between your flooring and the subfloor, this moisture will react with the alkalinity naturally present in the concrete slab, increasing the pH level at the surface of the concrete.
If the pH levels rise above the limits of your adhesive, the alkalinity will break down the adhesive. Therefore, for high moisture situations it's recommended to select a flooring adhesive with a limit of pH 11 or greater, to mitigate the risk of moisture-related adhesive breakdown.
3) Is Your Adhesive Covered by a Warranty?
Most flooring adhesives come with a short, 1-year warranty. However, some flooring manufacturers (including Milliken) are increasing the adhesive warranty to match their 15-year or lifetime warranty. This has a significant impact on the level of protection you have, should moisture become a problem.
4) How Restrictive is Your Warranty?
Flooring warranties can be notoriously complex and restrictive - often to the point of being virtually impossible to adhere to. Failing to meet the stipulations laid out in your warranty can invalidate it altogether. Even worse, many standard flooring warranties don't cover you against moisture problems.
Common restrictions and limitations include:
- Time limitations - the best warranties cover the whole lifetime of your carpet, rather than being limited to five or ten years.
- Site conditions - for some products, manufacturers may require a 'dust-free' environment - impossible to achieve on a working construction or renovation site. More realistic warranties may simply require that the surface is swept or cleaned prior to installation.
- Moisture and alkalinity - most standard warranties completely distance themselves from problems caused by "excessive moisture and/or alkalinity." When selecting flooring, check that your warranty specifically mentions moisture coverage - otherwise you're not protected.
5) How Does Your Flooring Solution Handle Moisture?
This is the most critical question to understand. Subfloor moisture problems are caused when liquid water forms: liquid water activates the alkalinity in concrete that causes adhesive failure; and water creates the damp conditions conducive to mold and mildew growth.
If you can eliminate liquid water, you can prevent moisture problems - and do away with the need for moisture mitigation products. Some flooring products work to allow water vapor to evaporate away, before it turns into liquid water - for example broadloom carpet, or Milliken's carpet tiles with their unique open cell cushion backing. In contrast, hard-backed carpet tiles or hard flooring products are backed by an impermeable membrane which traps the water vapor and prevents evaporation, so with a few degrees of temperature change it condenses into liquid water.
If your chosen flooring can eliminate moisture problems, then you don't need to specify moisture mitigation products as part of the installation process. However, even if you've already selected a hard-backed carpet product, switching to cushion-backed carpet may offer significant cost savings.
In fact, we've seen instances where a company has hard-backed carpet on-site ready to install, but when their moisture tests came back high, and they added up the costs of moisture mitigation solutions (which can be as much as double the cost of the flooring itself), and realized it would be more expensive to stick with their existing flooring option and add in moisture mitigation, than to switch to flooring that mitigates the moisture itself.
Even if you've already selected a hard-backed carpet product, it may be worth considering whether an alternative option may be more cost-efficient, taking into account the cost of the moisture mitigation products and processes during installation.