Concrete stains allow concrete artisans the ability to create unique and personal finishes for residential and commercial clients. But these products also have a certain level of transparency and react differently depending on various characteristics of the concrete. Contractors need to manage their customers’ expectations for a successful project from mock-up to finish, but there are also steps contractors can take to ensure their final project mimics the finish clients approved in the sample stage and on mock-ups.
“The best advice I can give contractors is make sure the conditions when doing the mock-up are consistent with conditions at the jobsite,” says Jacob Webb with NewLook International.
“Texture makes a big difference with color,” Webb continues, “especially when you are working with stains, dyes and even tinted sealer.” That means if you are hired to color a broom trowel driveway, make sure you have a broom trowel finish on the color samples you show your client.
Other factors that should stay consistent from a sample or mock-up to the jobsite include:
- Color application technique (sprayer, microfiber pad, etc.)
- Aggregate exposure
- Cleaning process on the concrete
- Number of coats of color, whether coats are thin or heavy, and length of time color sits
Brian Anderson, director of operations at Concrete Coatings, has a few suggestions for stain consistency on a project. “We recommend that you try to have every bottle of stain for a project from the same lot,” he says. “And always mix your bottles of stain together before application.” This will eliminate any variance from one bottle of stain to another. Anderson adds you should always use stains from one manufacturer, even when manufacturers’ color names are the same.
Shawn Wardall, president of Specialized Inc., Waterloo, Wis., is a decorative contractor working in both the residential and commercial markets. “A lot of our work is in customizing colors, so we are often mixing colors, layering colors, diluting them or making them more intense. When you do that, it is critical you pay attention to the formula and track your process to make those colors. You want to pay attention to your application technique too. Keep good records so you can reproduce on a grander scale,” Wardall advises.
If you are producing samples for an overlay where you have control over the mix and the final job surface, most of the jobsite variables related to the concrete will be eliminated. However, when working on a new construction or existing slab there are a variety of concrete variables to be aware of.
For one, the concrete mix design can affect color. Fly ash or calcium accelerators, for instance, can make acid stains turn out lighter or darker than expected. Other factors, including admixtures, amount of cement in the mix and type of aggregate, can also affect the final stain color.
“Especially when using reactive based products, contractors need to be conscious that no two pieces of concrete are alike and each piece has its own chemical properties,” Webb adds. “Those unique chemical properties depend on who finishes it, how much water is in the slab, where it was batched, when it was poured and a number of other jobsite variables hard for contractors to control.”
Webb says this is especially important on patchwork projects, where sections of concrete have been replaced or multiple pours make up a project. “Then when a contractor comes in and does the entire surface with a reactive based product they might see results where one section looks brown and another section looks red,” he says.
On new construction projects, contractors have the opportunity to plan the project with the GC, find out the mix design and let the GC know what they need for a successful project in the end.
“We like to have a prepour meeting with the general contractor to talk about protection and curing,” Wardall says. “We will make a point of that in our proposal to let them know we want to be part of the overall success of the project.”