Laminate floor mold disaster. Need suggestions please.

[Marcos77]

Hello. I'm new here and need some help please for the proper steps I need to take to install a new laminate floor on a concrete slab floor in a 1 story residential home here in South Florida. When we purchased the home in 2021 the previous owner had a flooring company install a laminate floor before the sale of the home. However, the flooring company decided to use drywall as a subfloor sitting directly on top of my concrete slab. Now we have black mold everywhere. What you see in the photos is a vapor barrier that is sitting on top of the drywall. See photos. This has been a complete nightmare for my family. I hired a mold remediation company and they completely removed the drywall/flooring and treated everything. Now I'm looking to do it myself and install a new laminate floor. I did a plastic moisture test and there is moisture coming up through my concrete. Should I use a class one vapor barrier epoxy on top of my concrete before I put down a 6 mil polyethylene sheeting? I'm just worried if I don't use an epoxy that I will trap moisture between the concrete slab and the 6 mil vapor barrier. Please advise me on the proper way to do this.

 

[Commercial Floor Rep]

You need to determine the amount of moisture you're dealing with before you can choose the correct abatement method. You'll need to hire someone to do Calcium Chloride testing per ASTM F-1869 or in situ Relative Humidity testing per ASTM F-2170. Once you can quantify the problem, then you can make a decision based on that information about what type of abatement system would be best.

Unless, you're going to assume that you are at 100% Rh. In that case, there are methods to permanently correct the issue even if you have 100% in situ RH, but they generally will require that the concrete slab be profiled (shot blasted) to a CSP (concrete surface profile) of 3, then you would apply an epoxy-based moisture control system followed by a layer of cementitious self-leveling patch. In essence, this "caps" the slab and becomes your new slab. It corrects the issue of not having an intact vapor retarder in contact with the bottom of the slab. One such system would be Ardex MC Rapid used with the appropriate self-leveling product.

For what it's worth, this is not typically something that a regular flooring store or a residential installer typically does. This typically falls to a commercial flooring contractor who would have the shot blasting equipment and expertise to install this type of system.

There are a lot of "band-aid" (roll-on) type of fixes on the market, but just understand they are relatively expensive and the biggest downside to many of them is that they typically have to be replaced each time the flooring is replaced. The system outlined above is a permanent fix, no matter what type of flooring is installed now or in the future - glue down or floating installation. While the upfront cost is higher, you're not spending that repair cost every time the flooring gets replaced in the future and should help when you sell the house, because you've addressed the situation correctly, and the new homeowner won't have to deal with a problem.

If a glue down floor is installed in the future, when it gets replaced, you'd simply tear down to the self-leveling and prep the self-level layer as needed to install another new floor. If the self-leveling gets a few "dings" during demo, it can very easily be repaired with normal cement based floor patch. Even if the epoxy moisture control system gets inadvertently damaged, it too can be repaired without having to shot blast or replace the entire abatement system.

Good luck with it and wish you the best.

 

[havasu]

You need to determine the amount of moisture you're dealing with before you can choose the correct abatement method. You'll need to hire someone to do Calcium Chloride testing per ASTM F-1869 or in situ Relative Humidity testing per ASTM F-2170. Once you can quantify the problem, then you can make a decision based on that information about what type of abatement system would be best.

Unless, you're going to assume that you are at 100% Rh. In that case, there are methods to permanently correct the issue even if you have 100% in situ RH, but they generally will require that the concrete slab be profiled (shot blasted) to a CSP (concrete surface profile) of 3, then you would apply an epoxy-based moisture control system followed by a layer of cementitious self-leveling patch. In essence, this "caps" the slab and becomes your new slab. It corrects the issue of not having an intact vapor retarder in contact with the bottom of the slab. One such system would be Ardex MC Rapid used with the appropriate self-leveling product.

For what it's worth, this is not typically something that a regular flooring store or a residential installer typically does. This typically falls to a commercial flooring contractor who would have the shot blasting equipment and expertise to install this type of system.

There are a lot of "band-aid" (roll-on) type of fixes on the market, but just understand they are relatively expensive and the biggest downside to many of them is that they typically have to be replaced each time the flooring is replaced. The system outlined above is a permanent fix, no matter what type of flooring is installed now or in the future - glue down or floating installation. While the upfront cost is higher, you're not spending that repair cost every time the flooring gets replaced in the future and should help when you sell the house, because you've addressed the situation correctly, and the new homeowner won't have to deal with a problem.

If a glue down floor is installed in the future, when it gets replaced, you'd simply tear down to the self-leveling and prep the self-level layer as needed to install another new floor. If the self-leveling gets a few "dings" during demo, it can very easily be repaired with normal cement based floor patch. Even if the epoxy moisture control system gets inadvertently damaged, it too can be repaired without having to shot blast or replace the entire abatement system.

Good luck with it and wish you the best.

Thank you for taking the time to write such a detailed explanation.

 

[Marcos77]

You need to determine the amount of moisture you're dealing with before you can choose the correct abatement method. You'll need to hire someone to do Calcium Chloride testing per ASTM F-1869 or in situ Relative Humidity testing per ASTM F-2170. Once you can quantify the problem, then you can make a decision based on that information about what type of abatement system would be best.

Unless, you're going to assume that you are at 100% Rh. In that case, there are methods to permanently correct the issue even if you have 100% in situ RH, but they generally will require that the concrete slab be profiled (shot blasted) to a CSP (concrete surface profile) of 3, then you would apply an epoxy-based moisture control system followed by a layer of cementitious self-leveling patch. In essence, this "caps" the slab and becomes your new slab. It corrects the issue of not having an intact vapor retarder in contact with the bottom of the slab. One such system would be Ardex MC Rapid used with the appropriate self-leveling product.

For what it's worth, this is not typically something that a regular flooring store or a residential installer typically does. This typically falls to a commercial flooring contractor who would have the shot blasting equipment and expertise to install this type of system.

There are a lot of "band-aid" (roll-on) type of fixes on the market, but just understand they are relatively expensive and the biggest downside to many of them is that they typically have to be replaced each time the flooring is replaced. The system outlined above is a permanent fix, no matter what type of flooring is installed now or in the future - glue down or floating installation. While the upfront cost is higher, you're not spending that repair cost every time the flooring gets replaced in the future and should help when you sell the house, because you've addressed the situation correctly, and the new homeowner won't have to deal with a problem.

If a glue down floor is installed in the future, when it gets replaced, you'd simply tear down to the self-leveling and prep the self-level layer as needed to install another new floor. If the self-leveling gets a few "dings" during demo, it can very easily be repaired with normal cement based floor patch. Even if the epoxy moisture control system gets inadvertently damaged, it too can be repaired without having to shot blast or replace the entire abatement system.

Good luck with it and wish you the best.

Great information. Thank you for explaining the process. I really appreciate it.