How many of your projects are on hold right now while you wait for newly poured concrete to dry?
Under ideal conditions, newly poured concrete requires four to five months to fully dry out before it 's ready to accept flooring. That's an extensive 120 to 150-day project delay: your client will be concerned when all visible progress on-site grinds to a halt and your contractors will be anxious, waiting for the go-ahead to begin the next construction phase.
Fortunately, there is another option: you can reclaim some of that lost time and reduce the time you need to wait between new pour and flooring installation. In fact, it's possible to reduce concrete drying time by more than two-thirds.
Today we're sharing the secrets behind an expedited flooring install: rather than waiting 150 days for the concrete subfloor to dry, you can begin installing flooring in merely 45 days.
The 150-Day Install
First, let's examine the standard construction process, whereby you need to let a newly poured concrete slab dry for up to five months before you can install flooring. What's the reason for this delay, and what are the potential risks if you try and speed up the process?
The Moisture Problem
Water is essential in constructing concrete subfloors: it makes wet concrete easy to pour and provides strength in the slab when it dries. However, this necessary moisture can cause problems when it's time to install floor coverings.
New concrete releases water vapor as it dries. Therefore, it's important to allow concrete to dry out before you install flooring on a newly poured slab. For a standard four-inch thick concrete slab, this takes four to five months to happen naturally: if it's left uncovered, water vapor can rise through the slab and evaporate away at the surface.
However, if a construction site is not yet weather-tight, the concrete slab can be subject to re-wetting when it rains, which can mean an even bigger delay while you wait for it to dry.
Unfortunately, due to ever tightening construction timelines, it's increasingly rare for concrete slabs to be allowed enough time to properly dry out before flooring is laid on top of it. Rather than being able to evaporate away naturally, water vapor becomes trapped at the surface of the slab. Furthermore, if you lay flooring on a still-drying concrete slab, you run the risk of severe issues arising:
- Mold and mildew - If you install flooring with an impermeable backing, then the moisture vapor is unable to evaporate away naturally. Instead, it is trapped underneath the flooring and condenses into liquid water, which creates the perfect conditions for mold and mildew to thrive.
- Adhesive breakdown - Most standard flooring adhesives can withstand an alkalinity of 9 or 10 pH, but newly poured concrete is extremely alkaline with a pH of around 12. If water vapor is able to evaporate away from the slab, this alkalinity never becomes a problem - but when the water vapor is trapped beneath flooring, it condenses into liquid water and activates the slab's elevated pH, causing adhesives to break down and your flooring to come loose.
In both cases, the result is the same: complete project failure and a sizeable cost for remediation.
Other Causes of Installation Delays
Excessive subfloor moisture can further impact project timelines. Your 120 to 150 days of concrete drying time can be further extended by other preparation stages that need to take place before you can install flooring on a new site:
- Moisture testing - Industry standard moisture tests are difficult to carry out and even more complicated to interpret, meaning you'll need to get an expert on site to perform the test. These tests are typically conducted just before you install flooring, and a high reading can mean added expense - with added moisture mitigation required or a delay while you wait for the slab to dry further.
- Moisture mitigation - With moisture-related flooring problems on the increase, it's more common to include moisture mitigation techniques in the construction schedule, ahead of flooring installation. Some of the more thorough moisture mitigation techniques, such as applying a floor sealant or two-part epoxy, which both seal the subfloor so that moisture can't damage your flooring, are very labor-intensive and require a lot of time to apply and dry before you can install flooring.
While moisture testing and moisture mitigation may only add a day or two now and then throughout the construction process, it quickly adds up. The project continues to fall further behind schedule, and your client becomes more and more frustrated.
The 90-Day Install
Fortunately, you can make strategic changes to your project specification to reduce waiting time. In fact, it's possible to install flooring only three months after a new pour: that reduces your wait time by 40% compared with the standard, 150-day install. But how is such a dramatic reduction possible, without compromising on quality and putting your entire project at risk?
Moisture is the root cause of your flooring installation delays: You need to allow water vapor from the concrete subfloor to evaporate away from the concrete slab to ensure you're not leaving your project vulnerable to severe problems, such as mold growth and adhesive breakdown.
Moisture problems arise when you install impermeable flooring over the top of a still-drying concrete slab. The water vapor is trapped and with the slightest fluctuation in temperature, condenses into liquid water - and that's what causes the damage.
Fortunately, it's possible to select flooring that doesn't interfere with the natural evaporation process. The majority of carpet tiles are hard-backed, which prevents water vapor from escaping the surface of the slab. Instead, you can select carpet tiles with open cell cushion backing.
The structure of this type of carpet tile means that water vapor is able to travel from the surface of the concrete slab, through the carpet tile backing, and then wick away at the seams of the tiles. As a result, evaporation happens naturally, and you don't run the risk of having vapor trapped under your flooring and condensing into damaging liquid water.
Keeping It Simple
Milliken's modular carpet can be installed as soon as 90 days after a new pour using Non-Reactive Standard Adhesive. It's simple for you to select a flooring solution to speed-up your project: Milliken's standard modular carpet paired with our standard adhesive.
Even better, there's no moisture testing needed so that you can avoid another potential delay and expense. Additionally, because you're installing flooring that prevents liquid water from forming, you don't need to worry about complex moisture mitigation techniques either.
The 45-Day Install
For the majority of projects, 90 days from new pour to flooring install will be ideal. But what about in those rare cases where you're facing an extremely tight deadline? When you're working on a time-critical project, every day counts, so it's possible to reduce concrete drying time even further to only 45 days after a new pour. That's a 70% reduction from the 150-day industry standard and a 50% reduction from the 'Milliken standard.'
You can achieve this by combining Milliken's cushion-backed modular carpet with Moisture Extreme adhesive, which has been specially designed for use in high-moisture environments. The modular carpet is then same, but with an enhanced adhesive.
Once again, there's no moisture testing required and no need for complicated moisture mitigation before installation.
Cut-Down Installation Time by Solving the Moisture Problem
Subfloor moisture is one of the most substantial risks that projects face: either you wait for it to evaporate naturally; you attempt to address it before installing flooring; or you encounter extensive, costly moisture problems in the months or years to come.
That's why concrete drying time can have such a significant impact on project timelines - it's one of the biggest sources of moisture on a new construction project.
The simplest way to reclaim valuable time on new construction projects and avoid the seemingly inevitable delays that new-pour concrete causes, is to specify flooring that removes moisture from the subfloor, rather than trapping it underneath.
By specifying carpet with open cell cushion backing rather than impermeable backings, you can reduce concrete drying time from 150 days to 90 using standard adhesive, or all the way down to just 45 days by combining the carpet with a specialist adhesive designed for high-moisture environments.