Contractor Forum: Moisture Mitigation
When it comes to fast-track construction schedules, moisture mitigation continues to be a serious issue in commercial contract work. We spoke with several contactors to hear about the various issues they face when dealing with moisture mitigation, what plans they have in place to deal with any situations that might arise, how they bid the work and any best practices they wish to share when encountering high moisture on a project.
“Moisture is an everyday part of our lives right now so the experience is often,” said Scott Spencer, president, One Source Commercial Flooring. “It is something that somehow the floor covering contractor has had to become very knowledgeable about and we’ve done a lot of education for both us and our staff to get smart on it.”
Jerry Kenney, vice president, One Source Commercial Flooring, added, “We’re just seeing it more often because of fast-track construction, and we’re running into it in renovation as well. So it’s become much more common than it ever was.”
Ryan Ulfig, controller, Master Craft Floors, echoes that sentiment. “It’s definitely become more of a problem over the last few years than it ever used to be and that might be in part because of the fast-track construction and the different regulations on what they can put in concrete and adhesives now. We do a lot of moisture mitigation, and we do it all ourselves.”
Andy Meyer, secretary and treasurer, Flooring Systems, said moisture mitigation is a constant battle. “The project is generally behind schedule and over-budget, the concrete floors get moisture tested and the results exceed the manufacturer limitations. We can solve the problem but it’s expensive and adds additional time. Many times, the flooring contractor is deemed to be the bad guy who is trying to profit from the situation.
“Currently, many owners and/or construction teams are choosing to use admixtures in the concrete that claim to resolve all moisture-related issues. Also, many manufacturers are testing and rolling out new products, such as floating underlayments like VersaShield or adhesive membranes like EnviroStix. Manufacturers are also raising the moisture limits on current and new adhesives.”
Del Church, president of Vortex Commercial Flooring, noted that as adhesives and installation procedures have changed, it’s critical to test moisture levels in concrete regardless of age or location.
“We have encountered high moisture levels on 30-plus-year-old concrete, so it is never safe to assume there will not be a moisture issue. On occasion you will come across older buildings that didn’t use a moisture barrier under the concrete. Also, depending on previously installed products and adhesives used, your visual inspection and test results may not indicate that moisture may be present or become an issue at a later date.”
“We started by making sure we do RH testing on every job,” said Ulfig. “And then for other jobs, if we’re bidding them, we’ll add a separate line item broken out just in case they do have a moisture problem—then they’re not completely blindsided by it later.”
Kenney describes a couple of steps that One Source Commercial Flooring takes. “When we submit for a general contractor project, we’ll outline the moisture limits for each of the specified flooring [types]. We’ll often put that in our quotes as well. We’ve also added some moisture mitigation language to our general exclusions on each of our contract documents, such as what we will and won’t include.
“When we begin a project, one of the very first things we’ll talk to a general contractor about is the conditions to moisture test and what we need to have slab-wise. So we’re talking about it on every project and we’re disclosing more information about limits early on in the process.”
Spencer added, “We’re trying to circle the wagon with the general contractor, the end user and the architect, and make sure what’s in the concrete specifications is going to be compatible with the floors. So often the right hand doesn’t know what the left hand is doing, and they’re putting on a curing compound on something that may impede the vapor remission and make it not work when it’s time to put your floors in. We’re trying to bring that up at the beginning of the process and have the contractor check back into his concrete specs.”
Meyer’s position is to educate everyone involved in the project about any issues and give recommendations to increase the chance that mitigation will not be required, “from placement, finishing and curing of the concrete, to selection of flooring materials that have manufacturer-recommended solutions. We also work closely with manufacturers to get jobsite visits to review mockups and ongoing installations. Then we use our relationships to obtain information about products and processes to make sure we are aware of the latest and greatest.”
Church stated, “We have aligned ourselves with various manufacturers in order to provide corrective options depending on the moisture levels and installation requirements.”
“Generally, we are required to bid this scope of work when the project is originally bid,” explained Meyer. “There are some projects where the mitigation is included in the scope and required to be in the base bid.”
Ulfig takes a different approach. “Moisture mitigation is always separated unless it’s specified to be included, because we know not everyone is going to want it included, so we separate it on our proposals.”
According to Spencer, different markets (for example healthcare vs. K-12) approach the issue differently.
“With healthcare, there’s usually a line built into the proposal request that says what the cost is to remediate the floor and they’ll carry it in their general conditions. In K-12, since there’s so much renovation work and I think the budget is a little tighter, we’ll include it in our notes or inclusions (not in exclusions).”
He added, “We’ll put a note that lists our square foot price. We use one particular brand which includes the whole system—shot blast, whatever that manufacturer’s material is, the floor prep—and we’ll just put that as a unit cost so they have that. Then if they do run into a moisture problem they at least have a square foot number in the back of their mind that they can plug in.”
Church stated that bidding the work depends on whether the bid specs call out a specific product or procedure. “Quite often these are addressed in the shape of an allowance in the event that it may be needed. On upcoming new construction the concrete may not be poured at the time of bid so there is no way to determine the moisture content. In many cases the mitigation will be part of our contract. However, we may have to sub it out.”
“Select flooring materials with moisture in mind; consider the ramifications of concrete mix, finishing and curing and get the building enclosed and the HVAC systems operational to start drying the concrete,” advised Meyer. “Keep water off the slab and hire educated contractors/architects.”
When a moisture problem is revealed, immediately address it, Ulfig said. “You can’t just pretend it’s not there. A lot of people try to say it’s close enough and just go for it, but then a lot times it’ll get back to them that it didn’t work. It’s important to be honest with the client and tell them upfront that you don’t have a lot of faith in the project unless they moved forward with moisture mitigation.”
Church echoes this sentiment. “Upon determination of the presence of moisture, inform the client or contractor immediately. Always keep in mind, you didn’t create their problem, but it is your responsibility to advise them of the condition and provide options to correct. Time is of the essence as the cost and time to correct the problem can be considerable and often takes time to get approval, get product and mobilize crews. Also, some of today’s adhesives are moisture tolerant up to 95% RH. Using that type of adhesive may eliminate the need for moisture mitigation.”
According to Kenney, moisture testing should always be the first course of action. “We’ve always tested vigorously and I say that because not everybody has and will run into resistance about testing. So we follow that to the letter of the law and begin with testing the slab the right way and then we escalate.
“If there are moisture-resistant adhesives or products that can solve the problem, that’s our first move. Remediation is really the option of last choice. We always drag in the manufacturer that we like to use, and we have them write a letter because it’s another set of eyes and another expert so it’s not just us. We’re also partnered with several companies whose core competency is to remediate slab moisture problems so we’ll often have them do this part of the work for us.”
“Documentation always helps—along with having all your moisture testing and a certified person doing your testing, whether it’s your own company or a third party doing so,” expressed Ulfig. “It’s always good to have backup and supporting documentation.”
Church stated, “Start of installation is acceptance of conditions. Test! Test! Test!”
Spencer voiced a concern in regards to moisture mitigation. “At these moisture remediation meetings, it has been my experience that the only guy that doesn’t get called to the meeting is the guy that put the concrete in place.
“Our belief is that you have the engineer swamp testing the concrete that’s being put in and certifying it—why doesn’t he get to be there at the end when the floor finishes are about to be installed to see what the final product is and to test it for the limits? I don’t understand why the engineer doesn’t have that last step to complete his sign off of the concrete.”
Kenney backed up Spencer’s concern, describing a presentation he and Spencer have created primarily for the A&D community. “In this presentation, we take people through the history of moisture testing, we explain what the ASTM standards say, we explain how to correctly test for moisture—and then we tell them why the flooring contractors should not be testing the slabs. We’re not trying to sell anything. We’re simply trying to tell the A&D community how it should be done and here’s why we should not be the ones to do it.”