OSHA and other regulatory agencies require that floors be marked for safety purposes. Striping or marking cement floors is always a challenge. When using paint or thermoplastic there are a few issues that make the task problematic. These are slick cement, curing compounds, grease and dirt. The good news is that these issues can be corrected. If you choose to paint your floors or use a melt down thermoplastic then the first thing you would want to do is a water test.
Water Test – To see if your concrete is ready for paint or thermoplastic you can try this simple test. Take a tablespoon of water and put in on the floor. If it soaks in in just a few second then your floor is porous enough to accept a coating. If it sits there for several minutes then paint or thermoplastic will not perform well since it cannot grab the surface or soak in. Keep in mind that if water can’t soak in then the paint will not either.
If your cement does not soak up water you do have the option of using an adhesive tape. We carry a product called Tuff Mark that is made to work on slick surfaces as long as they are clean and dry. It is very rugged and adheres very well. If you choose paint then the steps below will help. We have an article outlining the various ways to stripe factory cement floors at this link.
First, warehouse and factory floors are generally smooth much like your garage or house foundation floor. The finishing process that is used to smooth the cement to a slick finish closes the pores in the cement and prevents moisture from soaking into the floor like it would on say a driveway or other rougher cement surface. The problem that this creates for striping is that the paint has little to grab and subsequently will begin to flake or chip off. This problem is accelerated by forklift and equipment traffic.
Second, when cement is poured a curing compound is often used to help the concrete hold in moisture so that it cures slow and gains proper strength. This compound is present on the surface of the foundation and remains indefinitely. The curing compound can prevent paint or thermoplastic from adhering to the surface.
Third, over time cement becomes dirty and greasy. These types of surfaces tend to not hold paint well.
The problem of slick cement or curing compounds can be overcome via the use of a concrete grinder or scarifier. These machines take off from 1/16 to 1/8 of an inch of cement. This removes the top layer of the cement that would have the most curing compound in it and also roughs up the surface so that paint can grab it. Running a grinder or scarifier over the areas where you want lines will increase paint and thermoplastic adhesion substantially. After you scarify a strip for painting you can try the water test again. At this point the water should soak in to the cement more quickly than before.
Dirty and greasy cement can be cleaned using a degreasing compound and a pressure washer. You can also use a degreaser, a scrubber and a water hose. Once the surface is clean just let it dry for a few days and then apply your paint.
Author – Steven Cole (Economics, MBA – University of West Florida, Graduate Certificate – Stanford University)
30 years of experience in the Parking Lot Striping Business. Software developer for pricing striping jobs. Hands on experience with the Trusco Trueline Paint Striper.