Vapor Control

An outline of general procedures used in solving a moisture problem.
1. Masking & protection comes first, followed by shot blasting and edge grinding.
2. All structural cracks and control joints are prepared and vacuumed clean. This is done to properly seal up cracks and joints later on.
3. Our MES is applied with a squeegee providing a uniform coating over the entire surface.
4. Additional coatings are applied over the penetrating sealer.
5. A Portland cement based compound may be used to encapsulate the treatment allowing easy installation of flooring.
6. A thin layer of self-leveling topping creates a surface compatible with all adhesives and floor products.
7. After drying, the floor is sanded smooth, and is now ready for installation of any kind of floor covering.
The Problem
Background to a Costly Problem
Every year across America people are faced with a serious problem that affects untold millions. Floor system failures have become one of the most misunderstood phenomena in the modern construction age. As people, we all have a concern for buildings, because we spend most of our lives inside them.
The purpose of a building is simple; it is an environment in which you keep your things. Whatever those things are they reside upon the floor covering. The floor covering is affixed to the concrete foundation and the concrete slab is a natural moisture emitting mechanism.
It is logical then, to realize that the floor covering is financially-critical part of the building itself. If it fails unexpectedly, the costs associated with moving your things off the floor to solve the problem, and the downtime costs as well, can be catastrophic. Billions of dollars are lost in America each year due to floor system failures. Click here for more information
The Misery of Moisture Related Problems
The Super Store
A well-known, national retail chain moved into a larger building and sub-leased their old property out to two other well known medium sized retailers. The new tenants complained that the VCT was buckling, delaminating and oozing adhesive throughout the store… Click here for more information
Indoor Air Quality and Concrete Slabs
Many changes have taken place in construction technology over the last 20 years. Most notably, and to the detriment of indoor air quality, the advent of much “tighter” or energy efficient building envelopes and the increased use of concrete slab on grade construction. A related factor to these problems is fast-track construction, which seldom allows the time necessary for a concrete slab to dry enough to support a floor covering.
Problems with poor indoor air quality had been discussed as ideas for centuries. Yet only recently has our understanding of the microorganisms that live among us, become a serious topic for study. In door air quality sciences now constitute a multi-faceted world-wide discipline. Click here for more information
Five Options to a Vapor Emission Problem
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The Mechanisms
Indigenous Mechanisms of Moisture Movement
Microscopic capillaries within the concrete create the potential avenue for moisture to move through the slab. The differential of temperature & humidity between the moisture source and building interior causes vapor to be drawn out of the slab surface into the building envelope or become trapped under a low-permeable flooring material.
Moisture emits from concrete as a function of higher pressures moving toward lower pressures. Click here for more information
Contributing Sources of Moisture
Outside sources of water which contribute to a moisture condition can be accidental, or a normal function in nature. Accidental sources such as failed plumbing, over watered plant beds, sloping hillsides and poor trench drain systems are all examples of problems that should be carefully regarded, independent of the vapor emission rate of the slab. Click here for more information
Vapor Retarders
Vapor retarders can provide a very effective and necessary means of retarding the amount of moisture transmitting through slabs-on-ground from sources below. While often referred to as vapor barriers, few such materials truly provide a 100% barrier to rising moisture and therefore are more accurately referred to as vapor retarders. Click here for more information
Concrete Mix Designs
Water is the life blood of concrete. Without it, hydration and strength gain would not continuously occur. Concrete is one of those rare things that get stronger with age. Providing it stays moist throughout its life. Click here for more information
Concrete Curing
While the water/cement ratio of the concrete mix has a direct impact on the final permeability of a finished slab, the curing of the concrete has an important degree of influence upon the ability of a slab to transmit moisture vapor. Click here for more information
Concrete Drying Time in Laboratory Conditions
The time it takes for concrete to dry to an acceptable level for floor covering or coating application is dependent upon several variables including, but not limited
The Effects of Water/Cement Ratio on Slab Permeability
All slabs are porous as a result of their construction. Serious problems with porosity come from the extra water that was added in order to make a concrete batch a workable material. Concrete recipes have a water/cement ratio that should be carefully considered, as it directly impacts permeability.
The Measurement
Testing Paradigms for Concrete Slabs
All scientific tests generally produce results that are either subjective or objective. Furthermore, the dependent variable being measured generally occurs as a result of a stimulus that is either static or dynamic in nature. Click here for more information
Calcium Chloride Specifications and Test Reporting
Adapted from the vaprecision model calcium chloride test
Specifications
This test method was developed in the 1950’s and has been widely accepted by the flooring industry as a quantitative measure of slab moisture.
The Control
Means of controlling topical vapor emission and alkalinity
Topical moisture control can only be preformed by three means: penetrating liquids that enter into concrete pores, surface coatings that are bonded to the surface of the slab, and dispersive membranes that are also bonded to the surface but establish some sort of physical space between the concrete and flooring material or coating.
Tools employed for total vapor emission & alkalinity control
Providing a long lasting, fully warranted vapor emission & alkalinity control begins with properly engineered products designed strictly for the purpose of stabilizing, suppressing and diffusing gas.