How do concrete sealers work as a protective barrier?

A concrete sealer changes the qualities of the concrete’s surface so that when water comes into contact with it, the water molecules form tiny blobs on the surface instead of penetrating it. Then, the water droplets just roll away from the surface. Sealing gives concrete the same protection against oils and grease so even these normally hard-to-remove stains become easy to clean. It also protects against de-icing salts so sealing is especially important on exterior concrete surfaces that go through freeze-thaw cycles. It also eliminates the problem of mildew penetrating the cement, which can leave black stains on the surface over time.

How does it affect the concrete’s appearance?

Sealers usually impart sheen to concrete surfaces drawing out the rich colours of decorative concrete. Any decorative concrete finish will look much better when sealed. Exposed aggregate concrete will definitely benefit from sealing because it enhances the beauty of the decorative aggregates (i.e. pebbles and small stones) in the concrete. A tinted sealer can be applied to a plain gray slab or decorative concrete to add colour. Regular application of a quality concrete sealer will make your concrete more resistant to fading and wear.

How often should concrete sealing be done?

There is no exact rule to this because several factors are involved, mainly the type and quality of the product you used, the location of the area and the conditions the concrete is exposed to. A sealer, depending on the exact product, may last from 1 to 3 years.

Basically, you should seal your concrete as soon as you notice the coating is starting to wear away. You should also reseal coloured concrete as soon as you see the need for it because delaying the work may result to a slight fading of colour.

You should consider traffic and weather factors. Naturally, concrete surfaces that get a lot of vehicle traffic and is exposed to sunlight will wear faster than, say, a covered concrete area with moderate foot traffic. This is why concrete driveways are normally sealed more frequently than patios or sidewalks.

Recommendations: Seal concrete driveways once a year, ideally during fall to prepare it for winter conditions. It is ideal to re-apply clear seal on coloured concrete that get heavy traffic or is exposed to harsh winter conditions every 1 to 2 years. Seal other exterior concrete surfaces (plain or coloured) that do not get vehicle traffic every 2 to 3 years. For interior concrete floors, it’s okay to seal them once but apply wax coating periodically. With periodic concrete sealing, the next coatings only need quick and thin applications.

So, should you seal concrete?

While the benefits of sealing are obvious here, some people still do not seal their concrete. Some say it’s not necessary if you live in a place that has a mild climate or don’t get much rain. But the truth is sealing improves the overall appearance and life of all types of concrete regardless of the location. So, if you want to protect your investment, there’s no question to it – you should seal your concrete.

Decorative concrete has many faces. That has led to mystery and secret method stories about using concrete. Actually, decorative concrete is pretty straight forward. The name can fit concrete stamping, overlays, polishing, or engraving.

Stamping concrete requires new concrete. Specially shaped stamps are pressed into the wet concrete. The end result is built in brick, stones, tiles or other designs. The concrete can be colored when it is poured. The cured, stamped concrete can be sealed to protect the surface and keep the design beautiful longer.

Overlays are an additional layer of material poured over existing concrete. If the overlay is thick enough, it can be stamped or engraved with a decorative design that makes everything look brand new.

In some situations a classic glow on concrete that has been polished using special diamond grinders is all the useful beauty a floor or wall needs.

There are workshops at various freelance places for people to learn more about the techniques for stamping, overlay and polishing. They vary in cost and quality, but seldom are a total loss. It is difficult to get a good hands-on lesson for something that takes days or weeks to be finished. The workshops with the most clear slide presentation will probably give you the most content for the investment in training. A good slide presentation with easy to read handouts to apply afterwords would be even better.

Engraving on existing concrete with no new construction required, is one facet of decorative concrete that has been an unintentional secret. The methods can seem like ‘secret knowledge’ that few people have a chance to get.

Specially designed tools are used to engrave the concrete. Engraving works hand in hand with colorful stains and protective sealers. Engraving on existing concrete is a common sense choice that is also artistic, unique AND green. The low maintenance shouldn’t be a secret any more. Minimal upkeep over time and day to day cleaning keep decorative concrete beautiful for many years.

Engraving is a great business service to offer homeowners, businesses, and communities. Or it could be a smart add-on for an existing business such as concrete flat work, other decorative concrete or landscaping. Creative DIY people are beginning to see how they could enjoy doing their own engraving on the concrete at their house.

It is no secret that templates made of thick, reusable material are available to use with the engraving tools. Stock or custom designs for the templates help to keep the pattern on theme. Or those same tools can be used freehand with abstract patterns. Even more tools cut straight lines for geometric patterns such as brick or tile. When the engraver applies a little more geometry, those bricks can turn in artistic curves and waves along the concrete.

We all know how existing concrete can have chips or cracks. Flexible crack filler is available to put into the deeper or wider cracks. Often just a little planning can make the crack seem like part of the design instead of a flaw. People in one New York community are looking differently at the 50 year old concrete patio that had a rough surface. When their engraving contractor smoothed the surface, then stained and engraved a design, these folks had a treasure that their neighbors could envy.

The engraving and cutting tools I have been writing about are not secret. They are manufactured in Missouri, USA. These tools and supplies are shipped all over the world. The manufacturer offers a wide choice of tools that engrave on concrete by

• cutting with special blades,
• pounding with impactors, or
• blasting with sand.

The systems can be set up with a vacuum to keep dust low. One tool, the Sandroid has its own sandblasting and recirculating process. Tools and supplies are available as open stock. You can buy the tools you think would work best for you. You can get multiple tools or replacement equipment. Or you can choose complete business packages of tools and supplies all in a specially fitted cargo trailer. An advertising wrap lets the trailer act as a rolling billboard for the owner.

Sealers are mainly of two categories, topical sealers and the penetrating sealers. Topical sealers or film former sealers as they are called as they form a membrane, provide topical protection. They mostly give a glossy appearance to the concrete surface. Commonly used topic sealers are acrylic resins which are cheap and easy to apply. Epoxy is another one similar to acrylic resin only thing is it is more durable, so used in floors of garage, factory, etc. Penetrating sealers are good for dry surfaces. It does not change appearance of the surface. They chemically react and form a bond with minerals in the concrete. Helps blocking moisture on the surface and increase the density and strength of concrete. They are almost permanent. Silanes form a good permanent sealer which is expensive but is very effective. Silicates could also be used which is comparatively cheaper. Silanes and silicates are of smaller molecules. Siliconates are penetrating sealers of larger molecules. Though a bit expensive it is considered the best for highly porous substances. The different varieties of sealers are at times used in combination to give a greater strength and protection.

How to use a sealer? First of all, decide on the amount of sealer required based on the length and width of the surface that is to be sealed, the porosity of the concrete and also the type of sealant being used. The surface needs to be cleaned before applying any sealant. Check whether there is any grease, dirt or mildew. If so remove them. This is to ensure that the sealer penetrates the concrete. This can be done by wetting the surface which requires sealing and apply some cleaning stuff to remove the dir or grease if any. Power washer can be used to remove the debris properly. Dry the concrete thoroughly before applying the sealer. Then apply the sealer to the surface and allow it to dry.

The type of sealer to be applied depends on two things, the surface appearance and the maintenance. For a shining and glossy surface use the film former sealer otherwise the penetrating sealer. Depending on the maintenance required use the sealer that suits you. Sealers protect and strengthen the concrete works.

It is a cost-effective way to give old or new concrete an appealing look. Aside from looks and a reasonable price, exposed aggregate also features the main characteristic of concrete – strength. All these make this option widely popular. Because it’s very hard wearing, some common applications of exposed aggregate concrete are public areas including footpaths and traffic areas such as driveways, sidewalks, patios, plazas or pool decks. It can also be used on vertical applications such as decorative walls and building facades.

Aside from the fact that it is durable against heavy traffic and oftentimes cheaper than other decorative concrete techniques, here are more reasons why exposed aggregate concrete is popular:
It has practically limitless texture and color options allowing a customized look. With the exception of sealing the finish and cleaning it occasionally, this option is very low maintenance.
Its rugged surface poses less of a slipping hazard than brushed concrete.
It is resistant to harsh climate conditions.
Fewer tools or additional materials are needed in this method than other options.
This method is easier to learn and master than other decorative concrete techniques.
This technique has long been used since the early 20th century but it continues to be popular today with contractors discovering even more creative ways of using it. The two most common ways of achieving exposed aggregate concrete are:

1. Surface Dressing – In this method, decorative aggregate such as decorative stones, gravel, crushed glass, shells or quartzite is seeded onto freshly-placed cement. The cement must first be tapped about 5 to 9 mm below the required finish level before the aggregates are spread evenly over it and patted down the concrete surface. This method is ideal for smaller projects such as patios and garden footpaths.

2. Washed to Expose – The fresh concrete surface is washed away to expose the aggregates that are already part of the cement’s ingredients. Specifically, the cement’s fines are stripped away from the top 2 to 6 mm of the concrete surface to reveal the aggregates. This is the preferred method for commercial or heavy-duty applications.

In choosing a decorative aggregate, keep in mind that the type will determine the color palette of the finish and will also have an impact on the project’s overall cost. There are many reasonably-priced aggregates that will produce great results. Aside from color, hardness, shape, size and durability, consider locally-produced aggregates because they are readily available and, therefore, more economical.

Even more stunning effects can be achieved with exposed aggregate with the use of advanced techniques such as creating contrast by using different aggregates or alternating smooth surfaces with exposed aggregate finished areas. Some use strips of wood patterned stamped concrete as dividers to create accent. The possibilities when it comes to design are almost endless. What you can be certain of is that this decorative technique will offer you excellent value for your money.

Cory Grant is a second generation Decorative Concrete Professional. He is an enthusiast and enjoys sharing his knowledge on what he learns in the industry with other professionals and those who are seeking advice for their Decorative Concrete Project.