Hello and welcome everyone. My name is Dane Menke. I am the digital marketing manager here at Regenesis and LandScience. Before we get started today, I have just a few administrative items to cover. Since we’re trying to keep this under an hour, today’s presentation will be conducted with the audience audio settings on mute. This will minimize unwanted background noise from the large number of participants joining us today. If the webinar or audio quality degrades, please try refreshing your browser. If that does not fix the issue, please disconnect and repeat the original login steps to rejoin the webcast. If you have a question, we encourage you to ask it using the question feature located on the webinar panel. We’ll collect your questions and do our best to answer them at the end of the presentation. If we don’t address your question within the time permitting, we’ll make an effort to follow up with you after the webinar. We are recording this webinar, and a link to the recording will be emailed to you once it is available. In order to continue to sponsor events that are of value and worthy of your time, we will be sending out a brief survey following the webinar to get your feedback.

Today’s presentation will discuss retro coat vapor intrusion coding from land science with a focus on the installation process. With that, I’d like to introduce our presenters for today. We are pleased to have with us Tracy Fajette, business development manager for American Industrial Coatings. American Industrial Coatings is the certified installation contractor in Northern California for retro coat vapor intrusion coating from LandScience. With over 31 years of successful industry experience, American Industrial Coatings provides their clients with custom designed protective floor, wall, and tank coatings. Working with LandScience, Tracy and the team at American Industrial Coatings provide tailored solutions to achieve successful results on coating projects using the best testing and surface preparation method for each project to ensure long-term success.

We’re also pleased to have with us today, Nick Mjolsness, West Region Manager of the Land Science Division over Genesis. Nick’s role includes providing technical support in the design and installation of TerraShield, NitroSeal, MonoShield and RetroCoat vapor mitigation systems, and educating the environmental community on advancements in vapor intrusion barrier technology implementation and quality control by making presentations to environmental firms, regulatory agencies, and developers. Nick is a technical sales expert with years of experience in the vapor intrusion mitigation industry, specializing in assisting clients with solutions for the redevelopment of brownfield properties. All right, so that concludes our introduction, and now I will hand things over to Nick Mjolsness to get us started.

Well, thank you, Dane. I’m excited to talk to everybody today as this year marks the 10-year anniversary of RetroCoat. Land Science brought Retro-Coat onto the market in 2012, and since then we have seen really tremendous growth in the use of this system across the country. So as part of this 10-year mark, we thought it would be nice to put together a webinar that would focus exclusively on Retro-Coat. In this presentation, I’m going to talk a little bit about Land Science, some of the we provide, including Retrocoat, and then I will hand it off to Tracy Fajette with American Industrial Coatings, and he will talk about Retrocoat from an installation perspective. So LandScience is a recognized industry leader in vapor intrusion mitigation technologies. Our entire focus is to manufacture and implement the absolute best vapor barrier solutions in the environmental marketplace. As a division of the global remediation company Regenesis, we have a really deep bench of experts involved not only in vapor intrusion but also contaminated site remediation as well. So we work directly with federal, state, and local agencies to provide vapor intrusion mitigation training as well as having some involvement in VI guidance development. Our goal is to provide or to partner with engineers and consultants and to deliver the vapor mitigation solution for each individual site based on the property conditions, the regulatory environment, and your client’s needs.

So a little background on what LandScience offers. We have a full suite of VI technologies that are each designed for different site-specific needs to ensure the right solution is selected for your project. In addition, we can provide vapor barrier and venting design assistance on any project. We have a network of certified applicators across the country with multiple applicators within each region that we work with on a daily basis to ensure that every vapor barrier and venting application is a high-quality installation. In conjunction, the QAQC procedures taken by our applicators, we also offer an inspector training program that your team can get involved in. As a certified inspector, you can offer assurance to your client that you are out on site to oversee and document the installation and that the system meets your design specifications.

So a little background on vapor intrusion. Vapor intrusion has been a hot topic in the environmental industry for some time now. Generally speaking, a vapor intrusion condition can occur when contaminants present in soil or groundwater volatilize beneath a building and diffuse towards regions of lower chemical concentration, such as subsurface conduits, basements, and building foundations. The objective of VI mitigation is to interrupt the pathway between a subsurface vapor source and the potential building occupants. VI mitigation is not typically considered a remediation approach, but the design and implementation of vapor mitigation systems should complement remediation where appropriate. Passive vapor intrusion mitigation, which is really what we focus on at Land Science, involves the interception, dilution, diffusion, or diversion of contaminant soil gas entry into a structure. And the key here is without the use of mechanical means.

So these systems physically block the entry of vapors into a building and or will rely on natural mechanisms such as chemical diffusion and thermal or wind-induced pressure gradients to divert VOCs and soil gas away from the building, typically from a subsurface vent network to riser pipes and up to the roofline. There are a variety of vapor intrusion mitigation approaches. The pathway can be mitigated from typically the implementation of vapor barrier technologies, venting systems, or actually designing the building around these contaminants. The photos on the right hand side depict a vapor mitigation coating system retro coat being installed in an existing manufacturing facility and a building with a lower level open air parking garage, both of which are examples of a passive mitigation approach. The focus on today’s presentation will be on passive mitigation, but specifically retro coat.

Okay, so a little summary on the suite of vapor barrier technologies that land science offers. We have one single layer system for underslab applications and two three layer composite membranes for underslab as well. These are in addition to retro coat. TerraShield is a three layer composite membrane which consists of the TerraBase layer, 40 mils of our nitrile advanced asphalt latex, and then a protective layer on top of that. The Terrabase is the first layer that goes down in the field. It’s comprised of a layer of metallized film, a geotextile fabric on the underside, a polyester-reinforced grid, and this is all thermally bonded to a layer of polyethylene. The base layer is extremely durable with the reinforced grid and geotextile, and the metallized film is encapsulated within the polyethylene, which enhances the overall chemical resistance.

Nitroseal incorporates the original constructability benefits of a composite spray applied barrier consisting of a 10 mil HCPE base layer, bonded to a geotextile, and now incorporates the nitrile advanced asphalt latex at a 40 mil application. The land science bond layer is the final component of the system for added performance and durability. Nitroseal is ideal for sites with low to moderate VOCs and preemptive mitigation scenarios, where in many cases, engineers or developers want to use a spray applied approach versus a single layer sheet to ensure a vapor-tight, robust system. Similar to TerraShield, NitroSeal offers ease of application in the field and is designed to be implemented on a variety of building types.

MonoShield is our single layer, 30 mil geomembrane, which consists of a polyethylene and metalized film technology, a geotextile fabric on the underside of the barrier, and a polyester reinforcement grid on top of the barrier. The monoshield system is comprised of the mono-based sheet good and implements the use of our nitrile-advanced spray to seal off the seams, penetrations, and terminations. The mono-based layer provides greater tear and puncture resistance with the inclusion of the polyester-reinforced grid and geotextile. And the metalized film and polyethylene components provide the chemical resistance properties necessary for low to moderate level concentrations of VOCs, methane, and radon. As I think I mentioned at the beginning, the entire focus of the land science team is to support your project site from beginning to end.

Our team is available to review and make design recommendations during mitigation selection, in addition to support environmental consultants and GCs through the construction phase. Now, that being said, mitigating existing structures is much more complex than with new construction. With new construction, you have a clean slate, but with existing buildings, each site represents unique challenges. So initially, the mitigation options for existing structures was rather limited to basically you had two options. you could either install a vapor intrusion barrier plus a new concrete slab, or you could install a subslab depressurization system. What was missing was a mitigation system designed to be installed directly onto the existing concrete slab and act as a wearing surface. So with that in mind, the R &D team at Regenesis evaluated over a thousand different coatings, resins, and sealant formulations in order to create retro-coat.

The first coating design tested and approved by regulators to mitigate contaminant vapor intrusion in existing buildings. Retrocoat is chemically resistant to PCE and TCE in addition to benzene, and it’s the most chemically resistant coating barrier available for mitigating vapor intrusion. It’s the ideal product for existing buildings since, one, it can be used as a wearing surface and withstand forklift traffic. It contains no VOC, so it will not off-gas after application, and it can also be customized in terms of its look, color, to really fit the needs of the client’s wishes. We did do testing, chemical resistance testing, to the retro-coat barrier. The barrier system was tested against VOC’s PCE and TCE. A custom apparatus and testing methodology were developed to mimic conditions that are directly relevant to vapor intrusion. The testing was run for approximately 150 days and permeation rates were determined for each contaminant at challenge concentrations of approximately 25, 125, 250, and 500 parts per million.

RetroCoat was determined to be highly chemically resistant to these VOCs, exhibiting diffusion coefficients of 7.6 times 10 to the negative 14th meter squared per second and 8.2 times 10 to the 14th meter squared per second for PCE and TCE respectively. Thus validating efficacy of the RetroCoat barrier as a preventative measure against vapor intrusion for existing structures on contaminated land. Then we also have a white paper that goes into much more detail on the testing that was done and if anybody wants to read that let us know and we’ll send that out to you. At this point, I will hand the presentation off to Tracy, who will explain RetroCoat in greater detail and also get into what RetroCoat looks like from an application perspective.

Thank you, Nick. My talk today, I’m gonna focus on three areas of what RetroCoat is from an installer’s perspective. What it is and where we’ve used it before. I’ll give you a couple of examples of recent projects that we’ve done, one large one and one small one. then we’ll also go into greater detail on how this is installed. So first of all if you were to look at a concrete slab from the side view, all the moisture vapor is pushing up through the concrete and you’d be really surprised how porous that concrete is. There’s a lot of capillaries that can carry moisture vapor into the living area of a structure. RetroCoat is designed to encapsulate that concrete completely wall-to-wall and does not allow the moisture vapor to enter. So it is a barrier to protect existing structures from contaminated moisture vapor intrusion. It also mitigates against very chemically aggressive contaminates, chlorinated solvents, PCE, TCE, et cetera, all the bad stuff. It can also complement an active or a passive sub slab depressurization system.

It’s usually used where it’s either too costly or you don’t want to displace or disrupt an existing structure like where people are actually living or working. It can be used in just about anywhere there’s a concrete surface, residential office schools, industrial sites, anywhere there’s slab on grade or basement and basement walls, and my favorite, elevator pits. It can bond to concrete, CMUs, or even brick. As Nick mentioned, it’s a two-part, zero VOC, orderless coating. It’s a hundred percent solid so there’s nothing to evaporate when the coating is going down so that can be installed where people are actually living. It has a very high tensile strength, 9 ,800 PSI, is usually much harder than the surface that we’re actually applying it to. Most concrete is in the 3 ,000 to 7 ,000 PSI tensile strength. It’s also very, very thin. 24 to 40 mils is the maximum thickness for the system. So if you have doors or openings, it’s not going to do anything to impede that. It’s also what we call a wearing surface. can be used as a finished floor, especially in areas where there’s industrial work being done. It can be a non-slip floor. It’s also very chemically resistant to concentrated acids.

So if you’ve ever seen what wine, for example, can do to a concrete slab, this protects the concrete as well as allowing you to use it as a finished floor. Most of the time it’s going to be covered by some other form of flooring, carpeting, tile, or it can actually be used as a base for a decorative floor. I’ll give you a couple of examples that we’ve used the RetroCoat product in a couple areas. One is a manufacturing site and one was a downtown retail storefront in San Francisco. The manufacturing site is pretty interesting. It is on the old Alameda Naval Air Station in in Meadow, California. It was built in 1941 for the war effort during World War II and has been unoccupied since 1995. So you can imagine what it might look like. Thieves have stolen all the copper for the underground vaults of all the utilities that they had in the project. So those all had to be cut off and sealed.

There were all penetrations that had to be taken care of in the RetroCoat. The company that’s going to be occupying the project is going to use it as a manufacturing site and they had very, very high concentrations of PCE, TCE, vinyl chloride and of course benzene with all the gasoline they were probably using back in the day. We did this project in about a couple of weeks, a total of 150 ,000 square feet. Did it in stages obviously, we can do about 11 ,000 square feet per day installation on And it turned out to be a very clean project, and they’re very happy. The other project that we recently did was a downtown retail storefront. That’s something that we do a lot of here in San Francisco. It was a site built in 1960. There was apartments above the storefront, so that was a consideration for, you know, they didn’t want to disrupt the people living above, you know, by putting new concrete down. It’s about 1 ,900 square feet, and they were remodeling it for use as a preschool, so there was a lot of concern about what kind of contaminants were coming up through the concrete, and they had concentrations of the PERC, because it was an old dry cleaning establishment, and also benzene from an old oil storage tank that was leaking nearby. We did about 1 ,900 square feet and this took about three days to start to finish and they were ready to start entering into the project the day after we got done.

So basically, how is it installed? If you call LandScience, they’ll put you in touch with your certified installer for the area and they’ll come out and do a pre-site inspection and some testing. What we’re looking for is anything, any contaminants that might be on the ground or in the concrete currently, for example, oil, we’re looking to see if there’s any flooring or glue to be removed. We have to remove the glue from the concrete because if we start to do the prep process, it impedes that. That glue turns to rubber when we try to grind it. Also, we’re asking a lot of questions from an installer’s perspective. Are there any pre-install construction needs to be done? Any trenching that needs to happen before we put the retro-coat down? Because we want to have a complete wall-to-wall barrier for the retro-coat. We really don’t want to have to come back and re-coat an area that may have been penetrated.

And then, most importantly, we do some moisture vapor transfer testing. We use a calcium chloride test for that. And that is a little hockey puck of decascent. It’s those little white balls you get whenever you buy a piece of electronics. They’re designed to absorb moisture. So the way we do that, this is also a three-day test. We grind a one-foot square patch of the concrete that we want to test, and we usually put one these tests in every about 1 ,000 square feet of RetroCoat to be installed. We give that a day to breathe, let those capillaries open up so we get a clear test, and then we weigh the test kit, the little hockey puck, and then put a plastic cover over it. This allows the moisture vapor to come up through the concrete and get absorbed by the thousand chloride puck and then on day three we re-weigh the test puck and we get a before and ending starting weight of the hockey puck.

So in this case you can see that there was 0.73 grams of moisture vapor transfer over a 24-hour period. Anything less than five pounds per day is pretty standard, it’s pretty light, and we use that information to design the system. It’ll determine what materials we use and how thick the system needs to be to hold back the moisture vapor that’s coming up through the slab. From an installation perspective, again, if it’s less than 11 ,000 square feet per day, it’s usually a three-day process start to finish. The first day is prep. If you look at the picture, there is a machine called a shot blaster. That is a machine that shoots very small ball bearings about the size of a head of a pin into the concrete and get vacuumed up with a HEPA filter. What this does is it removes some of the contaminants of the concrete and also gives us the profile we need to bond or bind the RetroCoat to the concrete.

Also on the first day as we’re doing the prep process you’re going to uncover cracks that you didn’t see before and the cracks that are existing in the concrete, those need to be filled with a retro-coat gel. And you can see that in the picture on the screen, the white crack has the retro-coat gel in it. It’s an elastomeric gel that allows the concrete plates to move without cracking the retro-coat and also seals it from any moisture vapor transfer. Also on the first day is the primer installation. And again, that primer is to be anywhere from six to 20 mils thick depending on how much moisture vapor is coming through the slab. We put that primer on the first day and then on the second and third day we install the retro coat. Usually in two lifts or two coats 10 to 12 mils per. As you can see it’s liquid applied.

We use a notched squeegee to make sure we have the proper thickness that we’re putting down and then about every hundred square feet or so we’re going to do a mil gauge test on the retro coat to make sure that it’s the proper thickness. And what you get is a complete barrier wall to wall including any penetrations coming up through the concrete that mitigates against moisture vapor transfer. And you can see in the picture there’s a CMU wall with what looks like a 2×4 resting on it. That black area is a gap. There’s a little gap there that the retro coat did not fill. In these instances, whenever there’s a wide enough gap, we’ll use a retro coat caulking that will seal that. And that also is an elastomeric that allows things to move and still be able to seal it. As Nick had mentioned, it can be a finished floor. There are different colors available. If you want to use it as a finished floor, we can add aggregate for a non-slip finish in those industrial areas or color chips or quartz crystals, for example, to give it a more decorative look in retail environments. Probably the best thing to do if you have a installation is to get a hold of your representative for land science. They will in turn get you in touch with the certified installer for your area. They can give you a kind of a sidewalk as I explained but that would be the best place to start.