Concrete is one of the most low-maintenance building materials used today but it does need to be coated and protected for long-lasting use. Concrete can be covered with sealer or stain but they both have different functions!
Concrete sealers prevent the concrete from being damaged, while concrete stains are applied to the concrete to give it pigmentation. Concrete sealers penetrate and create a bond or form a protective layer on top. Stains react with the concrete or permeate the pores of the concrete to impart color.
Concrete is a universally popular choice of material for any construction due to its affordability, durability and versatility. Let’s see what the differences between concrete sealer and concrete stain are so that you can decide which one you need to use for your concrete.
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Difference Between Concrete Sealer and Stain
The difference between concrete sealer and concrete stain lies in the different chemical formulations of the two substances and the different functions they are suited for. You might often need to use both concrete stain and concrete sealer, depending on your preferences and needs.
Concrete Stain vs Concrete Sealer
Concrete stain is a way of imparting color to the concrete without creating a separate layer of paint. Concrete stains give rich and complex tones that depend on the specific characteristics of the concrete itself. Concrete stains are of two types.
Acid Based Concrete Stains
The first type is of solutions that contain water and some form of acid. The acid most used for this is hydrochloric acid. This solution of acid and water contains metallic salts that are soluble in the acid.
When the concrete stain is applied to the concrete, the acid reacts with the lime or calcium hydroxide of the concrete. This chemical reaction corrodes the concrete just slightly enough for the metallic salts to penetrate the concrete and stain it permanently.
Since these kinds of concrete stains create pigmentation through chemical reactions, there is a limit to the range of colors they can impart. The available colors are in the range of browns since those are the reactions that take place with the concrete.
Water Based Concrete Stains
Another newer kind of concrete stain known as water-based concrete stains is becoming a popular option as they can provide a much more extensive range of colors.
These contain acrylic polymers and pigments that are able to color the concrete without any chemical reaction. The chemicals in this concrete stain permeate into the pores of the concrete and settle as a pigment in the concrete.
There are different kinds of concrete sealers available, each of which has different chemical components.
Penetrating Concrete Sealers
Penetrating concrete sealers react with the material of the concrete to clog the pores of the concrete and repel water.
Penetrating concrete sealers often contain a chemical known as silane which forms covalent bonds with the concrete and repels both water and oil. Penetrating concrete sealers might also have siloxane, which also clogs the pores of the concrete and repels water.
Topical Concrete Sealers
The other kind of concrete sealer is known as topical sealers, which form a layer above the surface of the concrete to protect it from corrosion and damage.
Topical sealers can be made from acrylic resins which are extremely easy to apply and very affordable. They are known to give a smooth and shiny finish. However, they are not very long lasting.
Other topical sealers are made of polyurethanes which provide robust protection to the concrete from physical damage. Polyurethanes are polymers that have various organic chemicals bonded together by urethane.
Topical sealers can also be made from epoxy, which also is very resistant to damage from other chemicals and acids. Epoxy refers to a broad group of polymers made of hydroxy groups of chemicals and epichlorohydrin.
Concrete Sealer or Stain
Now that we have seen the different chemical components of concrete sealers and concrete stains, let us see what their different functions are and when you should use which one of these.
Concrete stains are used for aesthetic and decorative purposes to create the required pigmentation in the concrete. Concrete stains create textured, luscious and complex colors that are difficult to achieve with opaque paints.
Amongst concrete stains, if one requires natural tones and long-lasting color, then acid-based concrete stains are the better option. On the other hand, water-based concrete stains provide more opportunities for colors but are less durable.
Unlike concrete paint, concrete stains do not create an additional layer over the concrete but instead change the color of the concrete itself.
Hence one also needs to add a layer of protection to the concrete to ensure that the stain does not fade away and the concrete does not get corroded, undesirably stained or damaged.
Usually, concrete stain is covered with a layer of concrete sealer which not only protects the color and the concrete but also brings out the pigmentation of the concrete stain much more strongly.
However, concrete sealers can be applied with or without applying concrete stain before it. Concrete sealer is used to protect the concrete and it also imparts a slightly darker tone to the natural color of the concrete.
Amongst the different kinds of concrete sealers, the different options are suitable for different needs.
Penetrative sealers which clog the pores of the concrete and repel water and oil are an excellent choice for outdoor concrete since they offer excellent protection. They create a matte finish and are quite durable as well.
Acrylic resins are a very popular choice out of the topical sealers because they are very affordable and widely available. They are straightforward to apply and are used often even though they do not last for long and do not provide heavy-duty protection.
Acrylic resin concrete sealers are known to provide a lustrous and glossy finish, unlike penetrative sealers. They can also be used outdoors and especially for colored concrete because they provide protection from the sun’s UV rays.
Polyurethane concrete sealers are known to provide excellent protection though they are more expensive and are harder to apply. They are much more durable than acrylic resin concrete sealers and can be used in outdoor and indoor settings.
Besides floors, polyutherane concrete sealers are also a great option for concrete kitchen counters since they offer protection from damage and staining.
The epoxy-based concrete sealers are also very durable and difficult to apply. Though they can also be used indoors and can provide excellent protection from chemical damage, they can get a yellow pigmentation from the sun’s UV rays and are hence not recommended for outdoor settings.
Both polyurethane and epoxy-based concrete sealers are good options for places that require heavy-duty protection, such as factory floors, garages and so on.
Frequently Asked Questions
Can You Stain Concrete after Sealing It?
No, you cannot stain concrete after sealing it. You need to remove the concrete sealer by physically removing the concrete’s first layer or by using a chemical concrete stripper.
The concrete stain can function only by creating pigmentation on the surface of the concrete and hence cannot be blocked by the sealer.
Does Concrete Stain Need to Be Sealed?
It is not absolutely necessary to seal the concrete stain. Still, it is highly recommended because the sealer will ensure that the stain does not fade away over time by protecting it from chemical damage, water, oil and protecting the concrete’s surface from getting corroded.
Is There a Concrete Stain and Sealer in One?
Yes, there are many options in the market for concrete stain and sealer in one which not only creates pigmentation on the surface of the concrete but also leaves a protective membrane above the concrete like a sealer.
One such option is the LastiSeal Concrete Stain & Sealer which is water based and provides a range of 38 different colors. It can provide protection to the concrete for fifteen years.
Can You Add Stain to Concrete Sealer?
Yes, adding stain to tint the concrete sealer is a convenient and affordable way to add color to the sealer. While some concrete sealers might already have an added tint, you can also buy tints separately and mix them with the concrete sealer to create a colored sealer.