Mitigation of Concrete Slab Chemical Vapors

January 29, 2020

How do I stop chemicals gas vapors from contaminated soils passing though a concrete slab? This is a question I get frequently from owners and environmental mitigation experts.

Background

Chemical contamination vapors tend to pass though a concrete slab and get into the air above. Stopping the migration of the gas through a slab is frequently a requirement of repurposing a space.

The following steps can be used to mitigate chemical vapors into your space above it. Without the right tools these vapors in the air from contamination under that slab can be quite pervasive.

Each job needs to be evaluated on an individual bases. The tools below make the solution less evasive.

Cracks through the Concrete Slab

The most direct way for soil contamination gasses to get in is through cracks. Cracks are the path of least resistance, so most of your vapors come through cracks in the floor. That is a very easy fix Product #684LV – Methyl Methacrylate Crack Healer and Sealer.

The #684LV has about the viscosity (thickness) of diesel fuel. That makes it easy to gravity feed into small cracks small porous areas of the concrete. It welds the cracks back together with a bond strength that is greater than the tensile strength of the concrete. In other words structurally you have the monolithic structure that the concrete was intended to be.

Expansion Joints

Expansion joints are the also a very direct route for vapors to come in. To seal these joints use Product #632 – Chemical Resistant Joint Filler. This is a highly chemical resistant joint filler. It will not only keep the vapors out. If there is going to be a chemical exposure to the surface there will it will stop the chemicals from attacking your concrete and further contaminating the soils below it.

Sealing the Surface of the Concrete Slab.

The next step is to prime the concrete with Product #12 Chemical Resistant Primer / Sealer.

This is where there is a couple of ways to go. You can apply an additional coat or coats of the #12 or go on to Coating the Concrete Slab below. Our optional translucent Synthetic Anti-Skid Fine may be added to the #12 if it is used in additional coats as a clear sealer.

The Product #12 Primer Sealer can also be mixed with silica sand and used as a patching material for potholes and otherwise damaged concrete if required.

Coating the Concrete Slap 

In many cases you will want to install a coating over the concrete slab.  There are a number of options for doing this but here are a few of the most common ones.  The biggest difference between these coatings is the chemical resistance. Please See Chemical Resistance Chart for a comparison of chemical resistance of the products below. All of these products are 100% solid, zero voc.  All of the coatings in this section are highly durable and resist the abrasion of traffic. 

UV Resistant Top-Coating

For jobs that will see direct sunlight.  It may be desirable to add an ultra violet (UV) Resistant top coating for the systems above.  


Selecting the Right Floor for a Mechanical Room

July 27, 2015

Mechanical Room Floors are very unique in their use and conditions. You have to consider the installation environment and the function of the floor. Our Mechanical Room Floor will protect the concrete, and contain any liquids that spill.

Systems used in mechanical rooms should be zero VOC. You do not want solvent evaporating from your material. Evaporated solvent could be picked up by your air handling unit sending it through your building. The best way to prevent this is with a VOC free 100% solids resin system. A resin system that is 100% solids has no solvent (or water) in it. It also means when you spread a gallon of material on your floor after it hardens you still have a gallon of material. With water-based and solvent based materials you lose half the material to evaporation.

Mechanical rooms should be chemical resistant. Typically they are top coated with Epoxy.com Product #2 Chemical Resistant Epoxy – www.epoxy.com/2.aspx. If it is a chemical feed room you can supply a list of chemicals and concentrations to the technical support department so you can make sure the #2 is chemical resistant enough.

The systems used for mechanical rooms are impact resistant. The limiting factor is the strength of the concrete substrate. Properly installed the epoxy will stay bonded to the concrete. The only way the epoxy can chip is if you chip the concrete from underneath the epoxy. You can install a thicker epoxy floor for an additional cost if you think you need still additional protection.

The systems recommend for mechanical rooms are highly abrasion resistant and will easily handle traffic up to heavy fork lift traffic. The system can be made even thicker if you have an unusual amount of abusive traffic.

When the mechanical room is over a finished space, it is suggested that a crack isolation membrane be integrated into the system. This can be done with Product #32 Epoxy Membrane System. The advantage of #32 Epoxy Membrane Resin as part of the system is 100% solids and has zero VOCs.

If the mechanical room is shut down and you can handle solvent and want something still more flexible you can use Epoxy.com Product #459 a two component, high solids, elastomeric urethane instead of or in addition to the Product #32 Epoxy Membrane above. Product #459 exhibits excellent elongation properties along with high tensile strength and tear resistance to make it an ideal crack resistant membrane for use under Product #2 and all of our other epoxy mechanical room floor coatings.

One of the primary reasons you need a mechanical room floor over finished space below is to waterproof it. The above methods accomplish the waterproofing in the center of the floor. The edges of the floor can be protective with a coving material up the wall and around pipe penetrations. That can be accomplished with Product #720 Epoxy Coving Resin System which can be used to install an integral cove base for all of our epoxy based mechanical room flooring and most of our other epoxy flooring and coating systems. This provides seamless wall to floor protection.

For more information on seamless water and chemical resistant mechanical room flooring, contact Epoxy.com Technical Support Department at 352-533-2167, or email me at norm@epoxy.com.

 


Basement Waterproofing with Epoxy

September 4, 2014

Many homes and businesses experience leaky basements year after year. The worse time is in the spring after winter accumulation of snow. There are a number of prudent things that you can do to improve drainage against your foundation like roof gutters, grading and improvement of drainage. The recommendations here do not replace that conventional wisdom. It is designed to augment and improve upon these conventional methods.

The following article will be 1 of 2. This one deals with Block wall foundations. The next one will deal with poured wall foundations.

Waterproofing Block Wall Foundations with Epoxy

One of the nicest features of most of our epoxies are that they are virtually 100% waterproof. Water simply cannot pass through a good healthy layer of properly applied concrete, block, wood etc. Epoxy also has an incredible bond to concrete, cement, wood and many other construction materials. The bond strength of epoxy to concrete and cement is greater than the tensile strength of the concrete. That means on properly prepared concrete, epoxy cannot be removed without pulling concrete with it. The same is true about wood.

Considerations in Waterproofing with Epoxy

All this gives you the perfect combination to make a block wall watertight. There are limitations however:

  1. In an ideal world the epoxy should be applied on the positive pressure side of the wall, the outside. This way the pressure of the water is pushing it into the wall. That helps to mitigate the likelihood that you get so much pressure on the concrete block that you fracture the block. Typically by the time you know you have a leak you are already backfilled and landscaped so 95% of the time it is not practical to do on the outside of the wall. So you do it on the inside instead.

    Water exerts a pressure of less than ½ psi per foot of water depth and most basement walls are only 8 foot high, so you would typically only see 4 psi. So it is unlikely that you have a pressure greater than the tensile strength of the block. So doing it on the inside is typically the only economical alternative.

  2. The Product #1W Epoxy is much more flexible than the concrete block and mortar, but if the mortar or concrete gets any significant cracks in it, it will crack through the coating. On the other hand, the system is very easy to patch if it does crack. We also make a wall grade version of our crack isolation membrane Epoxy.com Product #32 – www.epoxy.com/32.htm – which can reduce the potential for small cracks (which are the most common).
  3. A clean substrate is required for maximum effectiveness – www.epoxy.com/surfaceprep.aspx. For technical support contact me at norm@epoxy.com or 352-533-2167

Installation of Epoxy Waterproofing on Block Walls

Once the wall is clean, you need to point-up (fill) any cracks, bad mortar joints, and larger holes that are in the block. Some people use conventional mortar and wait 28 days for it to cure as per the American Concrete Institute. This is a very inexpensive way to do it, but can be affective if done properly. A more effective way to insure the right results is the use of Product #2005 Epoxy Gel Adhesive – www.epoxy.com/2005.aspx. That insures that you have a tight bond over the cracked areas and have already produced a tight waterproof seal in that area. Also the #2005 Gel Epoxy is semi flexible and allows more movement before cracking that conventional grout. The #2005 allows your coating to be installed the day after the #2005 is applied.

Once the cracks and holes are repaired, much of your work is done. You simply apply 1 coat of Epoxy.com Product #899 – www.epoxy.com/899.aspx – Epoxy Primer and allow to dry overnight.

After the primer has cured overnight you can apply the optional crack isolation membrane Product #32W – Wall Grade, or proceed to the coating below. If you do apply the crack isolation membrane 2 coats of the membrane are best. One advantage of the two coats of membrane is that typically you can reduce the number of coats of top coating that is required to seal the block. As you put on the membrane be sure to check to see that the holes in the block are being filled as you go.

Depending on the porosity of your concrete and if you used the crack isolation membrane above you will want to apply 2-4 coats of 1W epoxy wall coating. As you put on each coat check to see that the holes in the block wall are being filled.

Summary of Waterproofing Basement Walls with Epoxy

In conclusion: Leaking basements are a major problem to many structures in the spring. The easiest time to repair them is during the winter when there is little or no leakage. Epoxy.com epoxy coating systems can affectively and economically solve most basement leaking problems. The final product is a hard attractive ceramic like finish that does not require additional painting or other finishes over it.

Next Issue: Waterproofing Poured Wall foundations with Epoxy.

Additional Information on Epoxy Coatings

Product #1W (Wall Grade)  Epoxy Wall Coating – a general purpose epoxy wall coating

Product #2W (Wall Grade) Cemical Resistant Epoxy Wall Coating 

Product #32 (Wall Grade) Flexible Epoxy Membrane

Where to Start when installing epoxy.


Seamless Epoxy Flooring Systems Explained

August 25, 2014

Epoxy.com offers many different types of seamless flooring. We offer so many kinds that sometimes it confuses people. The purpose of this article is to explain the differences, and to help you choose the right epoxy seamless flooring system for your application. In some cases the right seamless flooring system will not even be an epoxy. It may be polyurethane or Methyl Methacrylate (MMA).

Epoxy.com Epoxy Chip Flooring in VT rest area.

Epoxy.com Epoxy Chip Flooring on a VT Interstate Rest Area – Taken over 15 years after installation.


Epoxy Floor Coatings

Epoxy coatings can be effective flooring systems. Using Epoxy as a flooring system you need a 100% solids, zero voc, hard durable coating. You also want a coating that is available in multiple colors. These floor coatings can last for decades, so you want to pick a color that you like. Properly installed you will be looking at this floor coating for a very long time. This kind of flooring system is available in the following options:

  1. Epoxy.com Product #1 – www.epoxy.com/1.htm – meets all the criteria above. It has good chemical resistance, and excellent cost to benefit ratio. Great for warehouses, in areas with high traffic and only modest chemical exposure.
  2. Epoxy.com Product #1ESD – www.epoxy.com/1esd.aspx. This is the same as product #1 above but has conductive filler in it. Depending on the primer you use under this system it can be conductive (100,000 – 1,000,000) ohms of resistance or Electro-Static Dissipative (ESD) which is 1,000,000 to 1, 000,000,000 ohms. Used in plants that produce explosive materials like ammunition, fireworks, flairs, or explosive solvents, and used in areas of sensitive electronics, like computer server buildings, avionics, electronics assembly and electronic production areas.
  3. Epoxy.com Product #2 – www.epoxy.com/2.aspx. This is similar to product #1 but with a much higher chemical resistance. This major increase in chemical resistance is offset by only a small increase in the cost of the #2 over the Product #1. The product #2 is well suited for applications like garages, machine shops, sewer tank floors, battery rooms, cooling towers, grooming shops, dog kennels and all areas where an economical chemical resistant coating is required.
  4. Epoxy.com Product #633 – www.epoxy.com/633.aspx – is a highly chemically resistant epoxy floor coating and flooring system. Like Product #1 and Product #2 is extremely durable. Product #633 is typically used in areas where containment of aggressive chemical is imperative. For example Product #633 will hold up to continuous exposure of 98% Sulfuric acid for a period of at least 6 months without loss of structural integrity. Great for secondary containment for a large number of chemicals.

     

All the systems above can go over many different types of substrates with the proper surface preparation. All of the products above are available in 17 colors and can be color matched for an additional cost. The systems above can be combined with various anti-skid materials or broadcast with silica broadcast aggregate to produce a thicker floor

 

Chip Floor

Epoxy.com Chip Flooring – www.epoxy.com/chips.aspx – is the perfect blend of economy, durability, low maintenance, and gorgeous appearance. It uses a 100% solids pigmented epoxy base coat, a full broadcast of plastic chips, and two coats of chemical resistant clear glaze. The chemical resistant glaze also makes this easily the most non-yellow epoxy top coat available today. This easy to clean chip flooring system is best for high traffic areas where appearance, durability and low cost of ownership is a must. Great for commercial and residential kitchens, bathrooms, showers, grooming shops, kennels, veterinary clinics, garage floors, show rooms, rest areas, and much more. This product can be installed with an integral cove base. Epoxy.com Chip Flooring can be installed by a contractor but easy enough to be installed by a home owner. Epoxy.com Chip Flooring can be installed in a residence but is rugged enough to be used in the most demanding commercial applications.

Quartz Flooring

Quartz Flooring Product #15 – www.epoxy.com/15.aspx has a long history of being durable, attractive and non-yellowing. I personally installed this product on high school bathroom floors in the mid 70s. These floors have held up to the test of time with little or no wear, little or no loss of shine and little to no yellowing even under the urinals. This is also available with an integral cove base

Solid Colored Flooring

These solid colored floors are based around self leveling, trowelable or double broadcast application techniques. These floors are sometimes called shop floor. They are made to be thick and extra durable under extremely harsh environments. They can be top coated with any of the systems above under coatings. This kind of flooring is available in 3 speeds of cure: normal, fast, and cold cure. Solid colored flooring is also available with an integral cove base.

Methyl Methacrylate (MMA) Flooring

The big advantage of MMA is speed of curing. Each coat of MMA will cure hard to the touch in 1-2 hours. This allows the next layer to be applied quickly and traffic to be returned to it quickly. You can even build a fast setting integral cove out of MMA resin.

I personally installed MMA on one kitchen floor with a very tight schedule. The restaurant was only closed for breakfast. The project started with rotten plywood floors. At 10 PM the carpenters came in to work. They removed rotten floor and floor joists. They replaced the floor joists and the plywood. At 5 AM I went in with my crew and we primed the floor and sealed up the joints in the wood and the screw holes. At 6:30 AM we laid the floor. At 8 we put a glaze coating on the floor and by 10:30 the restaurant workers were on the floor prepping for lunch. The floor installation from start to traffic took just 5.5 hours.

Polyurethane Decking Systems

Polyurethane Decking – http://www.epoxy.com/elastomeric.aspx – is the system best used in areas where maximum flexibility is necessary. This is typically outdoors, waterproof applications like balconies.

Specialized Flooring

We have a number of systems that are specialized flooring like conductive and ESD (Electrostatic Dissipative) flooring – www.epoxy.com/conductive.aspx – and various hybrid systems. If your project does not seem to fit in the categories above email me at norm@epoxy.com or call us at 352-533-2167.

 

In conclusion we offer many types of seamless flooring systems, they can be used for commercial and residential applications. These systems are durable, economical, and easy to install even by homeowners. These seamless flooring systems may be made out of epoxy, polyurethane, or methyl Methacrylate (MMA). Seamless flooring systems are available in multicolored or solid colored. They range in chemical resistance from very good to resistant to aggressive chemicals. When in doubt what is right for your project send me an email at norm@epoxy.com or give me a call at 352-533-2167.