I got a call from a friend – I’ll call her Lucy –who feels bad because the color stain on her driveway is failing. It’s supposed to be a penetrating stain, sort of a tan color. Instead, the 3-year-old stain has turned pink and is flaking away.
The reason it makes her feel bad is that she and her husband – I’ll call him Dan — are both construction professionals. Lucy says she and Dan should have known enough to have avoided the problem.
But the truth is, sometimes you just can’t tell how things are going to turn out till after the fact. With concrete especially, each surface is unique. The same product may have small – or large — variations in performance from surface-to-surface.
And time and weather are both jokers in the deck.
Even for professionals.
Lucy and Dan did what professionals do. They required a test panel, which produced desired results. They watched closely to ensure the stain went down in accordance with the manufacturer’s instructions.
What did they do wrong? Not a thing.
What went wrong with the treatment? Flaking away suggests the stain didn’t penetrate like it was supposed to. Turning pink indicates the product had an unfortunate reaction to ultraviolet light.
Can the color be restored permanently? I went out on a limb and told Lucy I believed so, and then spoke with Chris Moore, our expert Research & Development technician in the PROSOCO Lab.
I can always count on Chris to give the bald truth about products and procedures, even if the truth is warty.
In this case, according to Chris, there is a wart or two, but a beautiful driveway is still possible.
Job one – remove the old stain. The new color won’t be able to penetrate with remnants of the old stain clogging up the microscopic concrete pores.
Remove as much as possible by scrubbing or powerwashing. For the rest, Chris suggested testing our Consolideck® Wax & Cure Remover, made for debonding waxes, acrylics, and cure and seals from concrete.
If that doesn’t work, Chris says, move up to Wax & Cure Remover’s stronger cousin, Cure & Seal Remover.
Dirt and algae on the driveway have to come off, too. Another wash with EnviroKlean® All Surface Cleaner gets rid of those contaminants, along with any residues left from the stain removal.
Lucy told me the concrete was originally etched by powerwasher to open the pores for the penetrating stain. But since the stain appeared to not have penetrated fully, Chris suggested another etch job, this time using Consolideck® SafeEtch.
This mildly acidic cleaner won the Expert’s Choice Award in the Most Innovative Product contest when it was launched at the World of Concrete, in 2002. Lucy and Dan won’t notice any difference in the driveway, but the new color should go in more fully.
And after three washes, that driveway will be sparkling clean!
Then comes the fun part – applying the new color.
Lucy is choosing from the Consolideck® ColorHard pallet of 14 UV stable colors for exterior concrete. ColorHard includes 19 colors, but those 14 are the ones tough enough to withstand the sun’s direct ultraviolet rays, which turned the preceding stain pink.
Once she settles on a color, she’ll mix it with Consolideck® LS® (lithium-silicate) hardener/densifier. The best way to apply is with a pump-up sprayer in a circular pattern. Use a cone-tip, rather than a fan tip, Chris says. It’ll help prevent spray patterns. Use a push-broom to even out the application only if needed.
One coat is all you need, but two coats increases the depth and vividness of the color, always a good idea for outside applications.
The hardener/densifier makes the concrete more water- and abrasion-resistant, but the color still needs some protection from the weather. Lucy and Dan don’t want a glossy finish, so Chris recommends treating the driveway with Consolideck® Saltguard®, a penetrating water- and salt-repellent.
In addition to keeping water out of the concrete, Saltguard® keeps destructive winter de-icing salts from soaking in and corroding the driveway’s rebar. Both characteristics help prevent cracking and spalling.
Nevertheless – and here comes one of the warts – the abrasive action of tires on the concrete, over the course of years, will eventually remove some of the color. The hardener/densifier will slow that process, but there will be some lightening over time.
That’s another good reason for putting down two coats of ColorHard.
What won’t happen is any kind of color shift, turning pink or flaking and peeling.
Now here is another wart – Saltguard® has a service life of 10 years or more. That means Lucy and Dan won’t be able to put down another coat of ColorHard for at least that long. ColorHard, and the LS it’s mixed with are water-based – Saltguard is a water-repellent – I’m sure you get the picture.
Nothing lasts forever, though, and the driveway will eventually need reapplication of ColorHard and Saltguard®.
Then it should be good for another 10 years or more.
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