How to Seal a Concrete Patio: Beginners Guide

  • September 14, 2019
  • / By Dale Keese
Women Hanging Out at Patio

Taking on any DIY project on your own for the first time is challenging to say the least. There are, however, instances when the process is relatively simple and can save you tons of money if you carry out the project yourself. One such activity is sealing your concrete patio.

Women Hanging Out at Patio

There are people who debate about the importance of sealers when it comes to saving the look of your driveway or patio. While this round may be won by the pro-sealer group, there is another debate over whether it should be done every few months or every few years. A ton of marketing by the companies that sell sealing products may make you believe that a sealer needs to be applied every year, but even if the process doesn’t have to be repeated so many times, it is important that you seal the concrete periodically to help increase the life of any concrete slab – the patio, the deck of your pool or your driveway.

There are a number of benefits of sealing your concrete surface. Firstly, water is the worst enemy of concrete. If your concrete patio isn’t sealed well, it is likely to be vulnerable to moisture. Water from rains, melting snow or your garden hose that you have used to wash the patio’s surface, can get through the concrete surface and encourage the growth of moss and algae.

Sealing a concrete patio can also help with stain protection. Patios are frequently exposed to a number of things like rust that can leave ugly looking stains on their surface. These range from leaves and dirt, to fertilizers, pet urine, oil or those occasionally spilled drinks. However, if you are using the right sealer, your patio will stay clean and these extraneous elements will not be able to penetrate the surface, leaving an unsightly stain on the concrete.

Patio with Wood Bench

Finally, concrete faces the risk of developing cracks because of the freeze-thaw damage that is common in colder climates. This means the concrete patio may develop cracks because of the expansion of ice that has seeped into the gaps. The water that enters the gaps tends to expand when the water freezes. A sealer is helpful in such a case, as it will keep water from sinking into the patio in the first place. The best way to check that your sealer is working properly is noticing that the water beads on the surface of concrete. If this stops happening, it may be time for you to reseal your patio.

To ensure that you do not have to face these problems, you should apply a sealer to your concrete patio and reapply it as and when required.

Types of Sealers Available in the Market

The sheer volume of sealers available in the market can confuse anybody who is getting their hands dirty for the first time. To understand which type works best for you and your patio, you should acquaint yourself with the different types of concrete sealers available.

Patio with Wood Furniture

Acrylic Resin-Based Sealers

The first type to be discussed is the variety that lays down a film of acrylic resin on concrete to lock the surface — acrylic resin-based sealers. These can be blended with other materials like epoxy, polyurethane or silicone to increase the concrete’s ability to withstand pressure. For this reason, some sealers can give you excellent performance for their cost.

There are many different types of acrylics available in the market and their quality and effectiveness also differ from one to the other. For example, styrene acrylic is lower on the performance grid as it may start yellowing when exposed to direct sunlight for a prolonged period. In this case, virgin or pure acrylic resin may be a better choice for you as it tends to last longer and doesn’t get discolored on exposure to the sun.

Epoxy or Polyurethane Sealers

The second type of sealers cost considerably more than the acrylic variety. This, however, doesn’t mean that it is superior in quality and performance. With these sealers, you will be able to observe a much denser layer that tends to get slippery and may defeat the purpose if used for an area that has a lot of pedestrians. This variety also prevents the concrete from “breathing” moisture that can turn into a problem as it may leave you with a whitish residue which can be seen between the layer of concrete and the sealer that you have used on the surface.

Penetrating Sealers

The best option for people looking to seal their patios — penetrating sealers — are products made of specialty resins like silicones, siloxanes and silanes. Specifically referred to as “penetrating” sealers, these products enter the concrete to form a type of barrier to any unwanted substances like oil or water that may otherwise harm the concrete if the chemicals hadn’t provided this shield. They are helpful if you are looking for a product protects surfaces from stains.

Here is a list of the best concrete sealers to help you out.

Patio with Plants

Step-By-Step Guide

Sealing a concrete patio may sound like a tedious task but with this guide, you will be able to get through it without any trouble. There are five steps in this process that have been put together to guide you as you successfully complete this project.

Step One – Get Rid of Dirt and Debris from the Surface

The first step in the process involves cleaning the surface of your concrete patio in order to remove all the dirt, dust and debris that may have collected over time. A stiff brush works well for this task but you may also choose the alternative of spraying the concrete with water to clean it. Keep in mind that if you choose the water cleaning method, you will have to wait for at least 24 hours to allow the surface to dry completely.

Covered Patio

Step Two – Clean Remnants of Paint, Grease or Oil Stains

In case the regular cleaning did not get rid of the old paint that was there on your patio, you will have to resort to another method. First try to blast the surface with sand or dry ice to remove this. If there are other stains — possibly from some grease or oil — on the patio that haven’t been dealt with when you cleaned the surface, you may have to employ a different technique to get rid of it.

Get a bucket of water and add detergent to it. Pour this detergent mixture all over your patio and get a stiff brush to scrub out the grease and oil stains. In case this too doesn’t work for you, try to use a grease solvent instead.  

In case the grease has already penetrated the pores of the concrete, it will be even tougher to get rid of it. For such problems, you can try applying a small amount of muriatic acid to the surface. After you are done with this, rinse off all remnants of the soapy water, grease solvent, paint residue or muriatic acid and allow the surface to dry.

Step Three — Wait for the Right Weather

It is important that you apply the concrete sealers only when you can count on getting at least three days when the temperatures stay between 40 degrees and 85 degrees Fahrenheit. This part is often overlooked by many as they don’t realize how important it is. Moderate temperatures ensure that the application is effective and that you end up with the best curing. Do not seal the concrete if you expect any sort of precipitation — rain, dew, snow, etc. - during this period.

Patio with Earth Tones

Step Four – Get to Applying the Sealer

After you pick the sealer of your choice, you will be required to follow the instructions given by the product manufacturer. This will also help you in determining what tools will be required for the process. The instructions make the job so much easier than figuring it all out on your own!

As a rule of thumb, try to start the process from one corner of the patio and work backwards towards the other end of the surface. In some case, you will need to add another coat of the sealer. If that is the case, make sure that the first layer is given enough time – at least overnight – to dry.

If the temperatures are low outside, give the first layer another full day to dry thoroughly before coming on with the second layer. Allow the second layer a full 48 hours to cure and finally clean it up with a garden hose. Once the process is complete, you will need to give it 10 days for the sealer to reach the ideal condition.

Step Five — Apply the Top Sealer for Best Results

Finally, it is recommended that you use the garden hose to water the surface after a 10-day waiting period. Follow up by spraying on the top sealer. There is no reason to worry if you don’t have a spray applicator. Simply pour the top sealer onto the damp surface and spread it with a brush. Apply a second coat before the first is completely dry and then give the patio a minimum of 36 hours before any people are allowed to walk all over it.

Sunny Patio

After Care

The process of sealing your concrete patio was fairly simple but to get the most out of this, regular maintenance is key. Clean the surface with soap and water every few months and if you notice some areas where the sealer has worn thin, a light re-application may do the trick.

You may be a little confused as to how often you need to reseal the concrete. This depends on a number of factors, which can differ from situation to situation. For example, the product used may influence the time it lasts, or the weather that the patio is exposed to. Finally, the level of wear and tear on the concrete differs from case to case. Concrete trade organizations recommend that you reseal the concrete every one to three years.