If you own a home or a building, it is almost a certainty that you have used concrete in the construction. Concrete is the most common man-made material on Earth, as well as being one of the strongest. Without concrete, there would be no foundations for buildings, no bridges, no sidewalks, to name just a few of the inconveniences. However, we often do not take the appropriate steps and measures to protect our concrete investments for the long term.
While concrete is strong and durable, it is a fallacy to believe that it needs no protection. In fact, without proper protection, concrete will not even be that strong or that durable. Just look at cracked sidewalks, crumbling bridges, and leaky foundations if you need further proof. Concrete can degrade due to the elements, wear, or really any number of reasons. While it has the potential to last for tens of thousands of years (theoretically), it can degrade over the course of a decade if the proper care isn’t taken.
The most cost effective way to protect concrete is to use a concrete sealer as soon as the concrete has finished curing. Without a concrete sealer, the concrete will be vulnerable to damage that could cost incredible amounts of money to repair – as many home and building owners have found out the hard way, it is a lot cheaper and easier to just prevent the damage by using a concrete sealer. Even if you move into a home or acquire a building that has not ever been sealed, it is not too late.
Concrete sealers come in a variety of types. Topical sealers like acrylics are excellent choices for decorative concrete to enhance the color, add a high gloss shine, or matte finish while protecting from sun, rain, mold and mildew. There are other surface sealers, like epoxies, urethanes, and polyaspartics, that should be used for high traffic/high chemical risk concrete surfaces that are found in places like industrial warehouses, retail stores, and even airports. There are penetrating sealers, like silicates that chemically react to densify and increase the concrete’s strength and penetrating waterproofers that create a hydrophobic barrier to prevent moisture and vapor transmission.
Basements: If you are looking to seal your basement floor look for a penetrating waterproofing sealer that will reduce hydrostatic pressure and vapor transmission. Do not use an epoxy, acrylic or latex based sealer that will peel, flake and delaminate at the first sign of water. If you are looking to seal concrete block walls or cinderblocks use a silane/siloxane blended sealer to fill the pores of the extremely porous blocks.
Patios: If you are looking to seal your patio of pavers look for a non-yellowing acrylic sealer; one that will hold up to wind driven rain and UV light. Acrylics are extremely common sealers with every manufacturer offering their version of an acrylic. Look for an industrial grade formulation, they might be pricier but they will last longer than a garden variety sealer. Acrylics are available in high gloss or a low sheen, solvent based and water based respectively. Water based versions are excellent for their low VOCs while solvent based acrylics will last a little longer.
Driveways: Look for a penetrating silane/siloxane sealer that will hold up to water, and salt degradation. Used by the Department of Transportation on all bridges and roadways, silane/siloxanes are excellent choices. Look for a silane/siloxane with a high percentage of solids since they will last longer and provide better protection.
Garages: The best garage sealers are epoxies and/or urethanes that are cyclo-aliphatic and aliphatic respectively. With these durable coatings oil and fluids have no chance to penetrate and they are easily cleaned up. Long lasting, look for a coating that will resist hot tire pickup.
Floors: For interior floors and warehouse floors look for a concrete silicate densifier that will create a smooth look after polishing. Lithium silicates are more reliable densifiers especially for densifying, hardening and increasing compressive strength.
Concrete is a delicate material. That is not to say that it is not strong – it is, in fact, one of the strongest man-made materials on Earth, and it can be reinforced with steel rebar to make it even stronger. It is also incredibly long-lasting, and has the potential to last tens of thousands of years, far longer than generations of human life. However, it is delicate in its creation, which needs to be fine-tuned to achieve the maximum potential strength of the future concrete.
Concrete is created through a precise mixing process of water, Portland cement, and some sort of aggregate, which can be sand and gravel. While many people use the term “cement” to refer to concrete, this is actually misleading as it is merely an ingredient in concrete. The concrete is mixed thoroughly with the proper proportions of each ingredient, before being poured soon thereafter.
After the pouring process, however, comes the most delicate part of the creation of concrete. Once concrete has been mixed and poured, is has to sit for a period of time before it has fully hardened. Without a constant level of temperature and moisture, the concrete will either crack from too much moisture, or dry out and crumble. These problems can be especially bad in the future, which is why many concrete professionals refer to a failed curing process has harming the concrete’s potential strength.
Most curing periods last around thirty days, after which the concrete can be walked on, used, and uncovered without any harm to its potential strength. It is also for this reason that you cannot typically apply a concrete sealer before the thirty day curing period. If you apply a concrete sealer to a concrete slab that has not fully cured, then you risk ruining and harming the concrete’s potential future strength. However, if you apply the sealer after the curing process has been completed, then your concrete will be perfectly strong and protected throughout its lifespan.
With the excessive number of companies manufacturing and distributing concrete sealers continuing to grow, it is important to eradicate some of the more pervasive myths. Most of these myths have to do with the concrete sealers and their propensity to repel or completely protect against water. Waterproofing concrete sealers are hard to find – typically the only types of sealers that can truly waterproof are lithium silicate/siliconate products that are not exactly everywhere on the market as they are more expensive to produce. Most companies simply content themselves to label their lesser (and less expensive to produce) products as waterproofers, when they will offer only a level of water resistance at best.
We now turn to examine the concrete sealers that claim to repel water. Water repellents are everywhere on the market, and many readers have been contacting me to ask whether or not products that claim to be water repellents actually are. In other words, does a water repellent truly repel water?
The answer is yes, they do. While there are many products that are developed and sold by unscrupulous companies who simply want to make money by offering a worse product for less money, there are a umber of companies that produce quality water repellent products. The key to see if your product is water repellent can, unfortunately, only happen after you have purchased and applied your concrete sealer. If you apply the sealer and any water that drips onto the surface of the concrete after the application and drying process has properly completed beads and drips off the concrete, then the product you used is indeed a water repellent sealers.
Water repellent sealers can be acrylics, but they are most often silane/siloxanes. Nearly all silane/siloxanes are water repellent, and they should be more or less bought with confidence. These products work by creating a hydrophobic barrier that locks out water with the particles of silane (that penetrate) and the particles of siloxane (that remain on the surface). This process creates the hydrophobic barrier that does not allow water to penetrate into the concrete, nor does it allow the water to even sit on the concrete surface, resulting in the beading and dripping off. Of course, water repellents are not waterproofers, and water will eventually seep into the concrete in minute amounts with the presence of enough water. However, as long as there is not standing water for a significant period of time, silane/siloxanes will offer comprehensive water repellent protection for your concrete surfaces.
With all of the concrete sealing product options on the market today, the oft-grandiose claims of many manufacturers and distributors can dupe many unsuspecting customers. The proliferation of the Internet has not helped matters, as a company can say almost whatever they want online without fear of great repercussions. One of the perennial claims made by most manufacturers and distributors is that concrete sealers and concrete densifers can actually fully waterproof concrete.
Waterproofing concrete is one of those benefits that everybody wants. The idea of making your home or building impervious to water damage is almost intoxicating in its desirability. However, for the vast majority of products, these claims are utterly bogus. While most products claim to offer complete waterproofing, they really only offer water resistance, at best. Some do not even offer any protection from water at all. How is the consumer unversed in concrete and concrete sealing to know which products are reliable and which are not?
Silicate densifier formulas have been around since the 1950′s and were initially used as concrete floor hardeners. Today because of their economical nature many concrete manufacturers and distributors claim silicates to be effective waterproofers. Silicate solutions have a place as a concrete treatment; however, their role should only be limited as concrete surface hardeners. Silicate solutions perform very poorly and ineffective as waterproofing sealers since they have a limited depth of penetration and they are unable to stop or reduce hydrostatic pressure. If you want to densify your concrete a Silicate hardener is an excellent option; however, leave the waterproofing to another product.
Our Take: Straight silicate densifiers cannot waterproof concrete; however, we reviewed the # 1 concrete waterproofer in this article.
Shopping for concrete sealer is one of the most difficult tasks to undergo. The big-box chains like Home Depot and Lowe’s do not really offer a wide selection of products, which can make it difficult to find the right product for your particular project. The same goes for local hardware stores, though they often carry random products from local companies that you wouldn’t be able to find in a large retail store. The problem with purchasing products in stores is that the offerings are typically far more limited. Concrete sealers are best chosen with the particular project in mind, as there are a number of different sealing options available.
The smart consumer will shop for concrete sealer online, though this presents its own sort of problems. There are a number of unscrupulous businesses out there that will offer a severely diluted product or products that can hardly pass as concrete sealers. However, these companies are fairly easy to spot for the savvy customer. One of the biggest tip-offs is if the company is an unrecognized name. The same goes for its website – if the website is choppy, old, and inoperable, the company probably does not have the money to spend on a proper website, meaning it likely does not offer a strong product.
Similarly, what claims does the company make? Many companies, even reputable ones, offer concrete sealers that are shipping in their diluted form. This means that these companies pre-mix their concentrated concrete sealer with water to their own ratios before send it out to you, the consumer. While this is not always a bad thing, especially if the company is well established and well-reviewed, a much better option is to purchase concrete sealer in its concentrated form. This allows you to purchase the concrete sealer and mix it yourself, making sure that you aren’t being cheated out of any expensive sealer.
Of course, while you will want to save money, it is a good idea to be prepared to spend a decent amount on a quality concrete sealer. Sure, you could purchase an inexpensive sealer, but you would simply have to reapply sooner than would a more expensive offering. The sealer will likely not even work as advertised, leaving you with concrete at-risk for various ailments. In the concrete sealing business, it is better to spend a little extra money on a product that you know will work, rather than skimping and regretting it later.
Finally, when purchasing a concrete sealer, always be sure to research the manufacturer’s product. The manufacturer’s will include materials like MSDS sheets and technical data sheets on their websites with their products, as required by law. These materials will give you some insight into the product you are considering: What is the ratio of the mixture? Does the product feature some abnormal safety precautions? What is the VOC content? There is plenty of information in these materials to help augment your knowledge and understanding of a quality product.
Our Take: Our go to concrete sealers include brands Scofield, Prosoco, and Kretetek.