I live in Ohio which is an area that can have tough, cold winters and hot, dry summers. Ohio’s severe weather swings take their toll on driveways and sidewalks, and make it common to see these surfaces in some phase of deterioration. In minor cases, the deterioration shows up as small circular spots of concrete that lift off or “spall”, leaving pock marks on the surface of the concrete. In more severe cases the erosion can be so bad that the concrete falls apart and ends up needing to be replaced. There are two contributing factors to this deterioration: The heavy freeze/thaw cycles that occur when you have major temperature swings and chemical degradation caused by the use of road salts and de-icing chemicals.
When chemicals are part of the problem, the deterioration is most evident on the apron of the driveway or the areas under where cars are parked. The reasons why these two areas are affected are easily understood. The driveway apron is subjected to road salts that get thrown up by the snow plows and the areas under the cars are exposed to road salts that get tracked in by the vehicles. Whether it’s freeze/thaw spalling or chemical erosion, the damage can be prevented by treating the driveway with a water repellent that will prevent the water and chemicals from soaking into the concrete and doing their damage. The process to do it correctly is really pretty simple. Just follow a few basic steps.
Start by Cleaning Things Up
This is the time to make your concrete look new again, by removing all the dirt and staining that has accumulated over the years, and the process is pretty easy to do. For this step you’ll need a power washer, a garden variety pump-up sprayer, a five-gallon bucket and some masonry cleaner. I like to use a product manufactured by SaverSystems, Inc. called Defy Safer Masonry Cleaner. The nice thing about the Defy product is that it works just like muriatic acid, which is a great concrete cleaner, but it doesn’t burn your skin or have the harmful fumes that an acid cleaner typically does. Like the name says, it’s “safer”.
To begin, fill a 5 gallon pail with 4 gallons of water and then add a gallon of the Defy Safer Masonry Cleaner. Pour this diluted mixture into the pump-up sprayer and you’re ready to go. Make sure that you work in sections and start by wetting the first section down with a garden hose. Spray a liberal amount of cleaner on the wet area, let it work for 4 or 5 minutes and then power wash the area clean. Move from section to section until the entire surface has been cleaned.
If You Already Have Damage, Patch Things Up
Using a hammer and a chisel, take a few minutes to knock out any concrete that isn’t firmly attached and in place. If it’s loose now, it’s only going to get worse so you might as well remove it and make the necessary repairs. For small pock marks, it’s a judgement call whether or not to fill them in. Just keep in mind that your repaired areas will always cosmetically look a little different from the rest of the concrete so if things are still pretty tightly adhered, you may want to leave the minor surface imperfections alone.
Take a Break, Maybe Go Fishing
This is always my favorite part of a project, because I love to fish! Anytime you’re working with concrete, you need to take your time. When concrete patching is first done, those patched areas will be highly acidic. That’s bad when it comes to coating them with a sealer or paint. Instead, wait about 4 weeks and the patched areas should become more neutral with a PH of say, around 7. With a more neutral PH, the sealer that you apply in the next step will work, so take a break.
Buy Some Water Repellent, and Don’t Be Cheap
It is very important that you resist the urge here to save a buck. My experience is that cheap sealers don’t last, it’s that simple. The cost of using a premium product is a little higher up front, but over the long-term, it’s a lot cheaper than having to continually re-do your project so step-up and buy the good stuff, you’ll be glad you did.
“Sealers” vs. “Water Repellents”
Ok, I’m not trying to make you a product expert here, but at this point you do need a little more information about the various products to choose from for treating your driveway. First, understand the difference between sealers and water repellents. Sealers are generally film-forming products, often times acrylics. Consider them sorta’ like paint, only clear. Sealers are not what you want so don’t buy them. They tend to stay on the surface and often times will make the concrete appear shiny and/or darker than normal. These products can easily peel or wear off. Sealers typically don’t last very long on a driveway.
Water repellents on the other hand soak into the concrete and won’t alter the appearance when applied correctly. They are very long lasting. You’ll get at least several years out of them…these are what you want. The most durable water repellents that I’ve found are silane/siloxanes. These are typically the most expensive but are the type you really should consider buying if you want your project to last. A good choice for your project is Defy Heavy Duty All-Purpose Water Repellent by SaverSystems, Inc. (www.saversystems.com). This product not only is an extremely durable silane/siloxane water repellent, but it also has a “salt-screen” in it that works to prevent damage from de-icing chemicals and road salts. Also, the Defy product is water-based, VOC compliant and eco-friendly. There are no harmful solvents to mess with, and I hate using solvent-based products.
Oh, one more thing. As great as they are against water and salt damage, silane/siloxane products typically don’t offer much protection, if any, when it comes to protecting your driveway from things like motor oil or transmission fluid so if you’ve got car problems…fix your car.
Spraying is Fast and Easy
When you start applying the water repellent, spraying it on, as opposed to brushing or rolling, makes all the sense in the world. First, it’s the fastest and easiest way to apply a water repellent, but there is another point to consider (as if “easy” alone wasn’t enough). The key to water repellents performing long-term is to saturate the surface. Often times when using a brush and roller you tend to under-apply the product. In other words, you don’t put enough of the product on to do the job.
You don’t have to go out and invest in an expensive sprayer. Stop in to the Home & Garden section of your local store and pick up a garden variety pump-up type sprayer. I suggest you get one that will hold 2-3 gallons of material. When you’re spraying you can go through a couple of gallons pretty fast. If it has a fan shaped nozzle instead of a cone shaped, that’s all the better.
Apply the Right Amount
Be careful here. More is not necessarily better. You simply want to spray the sealer on to the point where you saturate the surface. If you’re just “wetting” the surface you are probably not applying enough material. If it’s puddling up on you, you might be applying too much. Ideally you want to apply only as much material as the concrete can easily absorb. Don’t worry about it too much. You’ll get the hang of it pretty fast. If you over-apply the product and allow it to dry, it can darken the surface and make it appear splotchy. So if you do put too much on, before it dries, just spread the excess out with a dry brush or roller.
Let Things Cure
Good news, you’re done. Let things dry off and cure for several days and your driveway is all set. As the months begin to pass, you may start to lose some of the water beading that the product had when you first applied it but don’t worry, the water repellent is still working. It has penetrated deeply into the concrete and will continue to work well below the surface. After a good rain just keep watching your driveway compared to your neighbors. Yours will dry off quickly because the water isn’t absorbing in while your neighbors will stay wet for hours.
If you do start to think that you are ready for a maintenance coat, just give your driveway the “Water Test”. Pour a glass of water on the driveway. If it easily absorbs into the concrete it’s time to re-treat. If it lays on the surface, it’s not.