Concrete is a rough building material that is generally made from a composite of aggregate that has been bonded together with cement. The aggregate in concrete ranges in size from fine to coarse and is generally held together by cement that has a lime base.
When the aggregate and binder are combined with water, you end up with the familiar slurry used to pour sidewalks, driveways, garage floors, foundations, and more. A chemical reaction in the slurry causes the material to harden and become stone-like which makes it an excellent choice for outdoor applications.
Concrete has been around since ancient Roman times, and the well-known Roman Pantheon is an excellent example of a structure made from concrete. Other concrete structures include the Panama Canal and the Hoover Dam.
Over time concrete can deteriorate whether it is inside or outside. For outdoor applications, the deterioration may happen more rapidly, and it is common to find cracks in concrete slabs that are subjected to rigorous daily use.
Driveways, walkways, and garage floors all see heavy duty use and traffic that can result in cracks and spalling. Spalling is where pits form in the concrete, which weakens it and can cause cracks and imperfections to form in the surface. By correcting these imperfections, you can prevent more deterioration and achieve a smooth finished look.
Here are some of the benefits of resurfacing concrete instead of ripping it out and pouring new material:
It's important to note that regular bags of concrete cannot be used in place of concrete resurfacer. Regular concrete does not have the right bonding agents that allow it to stick to old concrete and the result will end up crumbling away sooner than an adequately resurfaced slab.
Additionally, resurfacers can be tinted and contain special additives that make it self-leveling for a smoother look. Bag for bag, resurfacing material costs more than plain concrete, but the result is well worth the extra dollars since you only need a thin top layer.
When you resurface concrete, you also get the opportunity to fill in any holes or cracks that may allow water in. When this water freezes in colder temperatures, it can put pressure on the concrete that causes more cracking and separation. Filling in holes also means less standing water on frequently trafficked areas such as walkways.
To resurface concrete driveways or garage floors, you'll need to go through a few simple steps:
For each of these steps, you'll want to follow the instructions and check the package instructions on the products that you are explicitly using. You can expect it to take about a day to resurface concrete in a garage or driveway, but it may take longer depending on the current state of your concrete slab.
For a larger project like a garage floor or driveway, you'll want to measure to get an idea for the square footage that you're working with and buy your resurfacer and other supplies accordingly.
The first thing you’ll want to do is clean your concrete to ensure that there isn’t any sealer, paint, dirt, oil, or other debris on the surface. To do this you’ll want to use a pressure washer that reaches 3500 psi, and a 25-degree fan tip to help channel the water.
Holding the wand 6-8 inches away from the surface, clean the concrete in slow sweeping motions until it thoroughly lightens and looks clean. If there is any mildew, stains, or algae, you may want to consider using a concrete wash for the best result.
This process may take longer for garage floors and driveways where oil stains and other debris are more common and harder to remove completely. If your concrete has a number of stains, using a concrete wash may help speed up the cleaning process and ensure your concrete gets as clean as possible.
Once the concrete has been cleaned thoroughly with the pressure washer, you'll want to remove any standing water, loose concrete pieces, and any other debris that remains. You'll then want to wet the surface evenly with water, without making any areas of standing water.
At this point, you can use the resurfacer to patch holes and other spalling and cracks. Use seven parts resurfacer to one-part water and mix well. Using a finish trowel, apply this mixture where needed and allow it to dry until you can stand on it without leaving a dent. Dry time for this step can take anywhere from 2-5 hours.
While you wait, you can use the weather-stripping to fill in the joints in the concrete. Tap the weather-stripping in with the chisel or screwdriver and a hammer. Make sure that some of the weather-stripping is above the current concrete line to keep the resurfacer on the slab.
Mixing the resurfacer for your project is an easy task but can require a bit of stirring. If you have access to a drill and a mixing attachment, that can make the process faster and less time-consuming.
Mix the resurfacer according to the package instructions by putting the water in the bucket and then adding the powdered resurfacer. Mix this for about 5 minutes to ensure that it's lump-free, and well combined before proceeding. It should be an easily pourable mixture without being too soupy.
If you feel the mixture is too thick, add water in tiny quantities until it is the consistency of maple syrup. If you accidentally add too much water, you can add in more powder to thicken it up again.
It's important to get the consistency right to get the most durable resurfacing mix possible. This will also reduce the likelihood of cracking, scaling, or the surface being perpetually dusty after you complete the project.
Once your resurfacing mixture is ready to go, you'll have about 20 minutes to work with it before it starts to thicken and harden. You'll want to work in sections in your garage or driveway and pour out a small amount of resurfacer at a time to trowel flat before moving on.
Try to spread the resurfacer to ⅛” to ¼” thick on the existing concrete surface. Use the trowel for smaller areas and the squeegee for larger sections. Do your best to avoid making any lines in the resurfacer but a few will be left behind that will be fixed in the next step.
About five minutes after you finish a section you'll want to take your broom and brush it over the surface gently to create a soft texture. The texture will prevent the floor from being slick when wet and also hide the tool marks left behind from spreading the resurfacer.
A nylon bristle broom is best, but others will also do the job. You'll want to create the texture at a 90-degree angle to the expected foot traffic for the best results. Once 20 minutes has passed, you can remove the weather-stripping, but be careful not to walk on the finished surface for at least six hours.
If there is the threat of rain during this time, you can cover the area loosely with a tarp or plastic sheeting. Otherwise, you'll want to leave it open to allow air circulation and natural drying slowly over the next several hours.
For driveways and garage floors, you’ll want to pour your resurfacer in sections and complete each section as you go since it will be difficult to reach them when you cannot walk over another resurfaced area.
The process takes longer for large spaces, so make sure that relatively good weather is in the forecast, and mix your resurfacer in smaller batches that are appropriate for the area you will be working on first. Keep in mind that you may need to re-wet areas if they become dry while you are working on another section.
For garage floors and driveways, it's important to measure your space and make a plan for how you will break up the area for resurfacing. Resurfacing products generally include the number of square feet that a single bag will cover, so you’ll have an idea of how much you should mix up for a particular section.
It’s not advised to mix up the resurfacer in advance because it will harden and not adhere properly to the existing concrete. Also, make sure to follow all of the resurfacing steps for each section, but you’ll want to complete all of the cleaning for the whole area at the start.