Achieve True Colors in Your Stained Decorative Concrete Projects

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.

Application factors

“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.

Jobsite factors

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.”

Wardall says if you’re on a new floor that has remnants of a cure and seal, you should remove it before staining. “We always like to sand a floor or use an aggressive brush action to get all those latents off, because if they are going to walk off the floor anyway I want them off before we stain,” he explains.

Decorative contractors can also suggest a curing paper as an alternative to a cure and seal; however, proper installation is crucial because differential drying can cause dark and light patches on the slab that can show through a stain.

Another thing Wardall discusses with the GC is the planned finish. “We want to avoid any burnt finishes from hard trowelling. A good hard troweled finish can be very good for acid stained finishes as long as they are not burnt. We like it at a point where the concrete starts to smooth up and become burnished, but if it goes any further the surface will close up and the stains won’t penetrate,” he explains.

Anderson suggests contractors emphasize to the GC the importance of floor protection. “Other subs can do things to the floor that you can’t see. Sometimes you don’t see it until after you start cleaning, or worse yet, after you acid stain.” Some of these contaminants that can ruin a floor and affect the coloring process include gasoline and oil spills; lines created by the tape carpenters use to lay out walls; chalk from snap lines; markers; spilled soda; chewing tobacco; pallets or piles of lumber stacked on the concrete.

Contractor Bart Rocket, The Concrete Artist, Berlin, N.J. has been installing decorative concrete projects for 23 years, from concrete placement through decorative application. Working in the high-end residential and commercial markets, Rocket finds his application technique transfers well from mock-ups and samples to final project because it is less susceptible to jobsite variables. “We use shake-on color hardener, which is almost fool proof. It’s more work, but there are advantages over integral colors,” he says. “And we use a custom blend of acid stains and water-based stains on top of the color hardener and most of our jobs are all five and six colors. By using multiple colors, you can hide more things in the concrete.”

Jobsite mock-ups

The best mock-up scenario is one in which the contractor has the opportunity to take a section of the actual jobsite slab and create a realistic mock-up. This is especially important on existing floors where it might be impossible to find out the concrete mix design and other unknown factors.

“I usually find a mechanical room and do my samples against the wall, and I look for a place that has a control joint running through it so they can see what the real world expectation level is,” Wardall says. “I always want to do a reasonable interpretation of what can be obtained on the actual floor and intentionally have some flaws so they can see that as the character that might come out on the floor.”

Manage customer expectations

The most important thing you can do to ensure your client is happy with your finished project is educate them on the realities of stained concrete. The finish isn’t for everyone. “With acid stains, you never promise a color, even after you have done a mock-up,” Anderson says. “If someone tells me they want an exact color, I tell them they probably don’t want an acid stain.”

“When we make a sample I tell the customer the color will match within about 95 percent; I don’t tell them there will be a 100 percent match,” Rocket says. “I explain to them we are working with concrete and there are variables.”

Rocket adds that a good way to manage expectations with the customer is to have them think of the project as a whole and not just focus on color details. “We have a showroom, so it’s easy for customers to come in and see our work. We can also take them out to a couple jobs and give them a feel for what the big picture is.”

Rocket says at the end of the day, you might be happier without certain customers. “If you’re dealing with a really picky customer, that’s probably not a customer you want. If they are picking at you on day one, then they will pick at you until you get paid. Those really aren’t the customers you want.”