Abstract Concrete wins first place in Restoration Contest

05/25/09

I am pleased to announce that Abstract Concrete took first place for Interior in the 2008 Concrete Decor Magazine Restoration Contest.  The project was located at the Detroit Water Building in downtown Detroit.  You can read more about the project by clicking on the project profile located on our homepage. The article can be found... more

 


Don't miss this informative article located in our blog discussing pH and vapor transmission as it relates to floor covering failures over concrete.  This very real and costly problem can be prevented.   Don't have a floor installed before knowing all the facts!  Read it here...


Abstract Concrete featured at World of Concrete

Abstract Concrete was selected to demonstrate cutting edge decorative concrete techniques at the World of Concrete Artistry in Concrete event in Las Vegas.  Our creative designs and innovative techniques as a leading installation company was recognized by, and led to our selection by Concrete Construction Magazine, the event sponser. To read the article visit Concrete Construction Magazine



Caution: Wet Concrete

 

         I’ve often said, “Bad concrete has been very good to me.” As a technical specialist in the commercial resilient flooring industry, concrete issues are an almost daily topic of discussion, and my clients need answers. Flooring failures attributed to moisture-related concrete problems are at near epidemic proportions today. Coatings, carpet, vinyl, rubber, wood, laminates and most floor coverings are affected to one degree or another by pH issues and excess water vapor emissions through a concrete slab. Moisture causes gaps between tiles, adhesive oozing, bumps, dents, cupping, bubbles, indentations, wheel marks and more. Left uncorrected, these problems can evolve into health and safety issues caused by mold, mildew and floors lifting. Here’s a crash course on concrete floors and the issues related to flooring installed over concrete. I hope it will go a long way to helping you to understand what could go wrong. 

 

         Moisture related failures of resilient floor coverings installed over concrete have focused unfairly over the years on the premise that the flooring product itself is at fault or the flooring contractor, perhaps, did not install the product correctly.  In reality, the vast majority of flooring failures result directly from high emissions of moisture (moisture vapor, if you will) from the concrete slab over which the floor covering has been installed.  When discussing these issues, people in the trade may refer to this as a water problem, hydrostatic pressure, capillary action, or moisture migration.  

 

Concrete is porous by its very nature, and the degree of porosity has to do with its design recipe, placement, and cure method.  Moisture vapor emission is a function of that porosity, combined with environmental factors that influence and drive it.  The greater the porosity, the greater the potential for moisture vapor to move at a volume intolerable to the floor covering.  The problem is further exacerbated when high levels of alkalinity move with the vapor emissions and attack the adhesive that bonds the flooring to the concrete.

 

Moisture related failures in flooring applications is not a human error phenomena, with the exception of the unwillingness of people to accept that nature is indifferent to their contract specifications, construction requirements and schedules.  Environmental conditions (temperature, humidity and dew-point, for example) and the chemistry of concrete will, by and large, determine moisture and alkalinity emission rates that will have a direct bearing on the success or failure of any flooring installation.

 

 

What is Vapor emission?-

            Moisture/Vapor Emission is simply the movement of moisture through concrete to the atmosphere. 

 

What causes high levels of vapor emission?

            There are several situations that can cause high levels of vapor moving through the slab. If there is  variance in humidity between the air above the slab and the concrete itself, this often causes slow drying time. Excess water being added to the mix design can prolong dry time as well. Another common problem is what we call an “active source”, this is when there is water seeping under the slab from either rain runoff or a plumbing leak. Sometimes we see job schedules get rushed and there is not enough time for the slab to dry out. The last is a rare problem yet the most serious. This is true hydrostatic pressure. Hydrostatic pressure occurs when the water table is higher than the slab. Although this is serious, there are products that stop hydrostatic pressure as well as all the aforementioned issues.

 

How do I know if a vapor barrier is needed?

            There are a number of ways of doing this. The most simple and what we refer to as “the poor mans method” is to tape 4 mil plastic and look for condensation over the next day or two. There are many electrical testers out there that work well. I prefer the calcium chloride test. These tests can be purchased for 7-20 dollars each and you should do one for every 700 s/f or so. Concrete floors should be tested for alkalinity before the installation of resilient flooring (epoxy etc.). The pH scale runs from 1 to 14, with 7 being neutral. Below 7 is considered acidic while above 7 is alkaline. When testing for pH, the allowable readings for the installation of resilient flooring are 6 to 9 on the pH scale. The quantity of moisture is noted as the rate of moisture vapor emissions, measured in pounds of moisture over 1000 square foot area during a 24-hr period. There are vapor barriers out there that will withstand up to 25 pounds per 1000 sqft. One common misconception is that if a slab is 28 days old it is ready to accept resilient flooring. The truth is even an elevated slab that is up to eight months old can emit vapor well over 12 pounds if the conditions are not right for it to wet out. The 28 day or 30 day mark is only related to the slab reaching 80% of its intended compressive strength, nothing to do with vapor emissions. The other fallacy is that if there is a vapor barrier under the slab you have no worries. This is simply not true. I have never seen one get installed that doesn’t get punctured, torn,ripped, and generally trashed during the install of the slab. And they can often hinder as well as help. We have gone to requiring a vapor barrier on non-breathable systems to extend warranty against de-lamination due to vapor on all non-breathable systems we install.

 

Do upper level slabs dry out quicker?

            This is a misconception. Most pan filled cements are designed with a light weight aggregate that act as miniature sponges plus additional water is needed in order for the cement to be pumped. This slab very well may take longer to dry out than a slab on or below grade. Much depends on weather the air has been conditioned during the drying phase.

 

Will acid etching create a PH neutral slab?

            Many manufacturers recommend acid etching to achieve an acceptable PH level. Etching changes the PH at the surface level only and is temporary. Etch a slab that is suspect and then check it in two weeks, it will spike right back after a given time if it has a PH problem.  There are VB products out there that are absolutely unaffected by PH and if you want to be sure, its the way to go. Moisture Vapor barriers may seem like an unnecessary expense, but they are in fact cheap insurance against a failing floor that will have to be replaced.

           

How long does a slab take to reach acceptable vapor emission?

            This depends heavily on mix, environmental conditions, humidity and slab thickness. On average though, if the conditions are 50% humidity with an air temperature of 73 degrees, it will take one month per inch.  Therefore, a standard four inch slab will take four months to achieve a safe level of vapor emissions before installing a non breathable flooring system.

 

How long do I have to wait to install a vapor barrier?

            We have products that can be installed in as little as four hours after it has been poured. In most cases we install our systems between 1-7 days after the pour.