Concrete, by nature, is extremely porous filled with endless pores and capillary voids. Think of a sponge, when dry it is hard and dense but when it comes into contact with water it fills up and becomes weak and wet. In order to prevent concrete from seeping up endless amounts of water a waterproofing concrete sealer should always be applied. Concrete basements, concrete driveways and concrete foundations should always be treated with a waterproofing sealers since they are most susceptible to damage.
If a basement is composed of concrete blocks or concrete cinderblocks it is best to use a Silane/Siloxane based sealer. The mixture of the two types of sealers and the larger size molecule will provide excellent water repellency to the overly porous blocks. Concrete blocks are the most porous concrete structures since the pores and voids are large and the thickness of the concrete is not extremely deep. It is essential that a concrete block basement is sealed as soon as possible to prevent water damage from the close proximity of the water table.
If it is a poured concrete foundation or a concrete driveway it is best to use a penetrating densifier and waterproofing blended sealer. The combination of the smaller molecule with its densification properties and the larger molecule with its waterproofing properties is the ultimate solution for preventing the penetration of water.
Our Take: Excellent silane/siloxane concrete blocks and cinderblock sealers include Okon S-40 and Siloxa-Tek 8500 and penetrating densifiers and waterproofers include Lithi-Tek 9500 and Euclid’s Diamond Hard
As the areas of our homes that are probably the most vulnerable to damage, basements require a little more care and consideration than many other parts of our houses. Water damage typically will not plague a home, even on the ground floor. However, since basements are actually located underground, they are at a higher risk of damage from the elements, especially water damage.
Water damage typically occurs from flooding. While flooding can be a surprise, such as from flash floods or natural disasters like hurricanes, the flooding that can regularly plague basements generally builds up over time. Areas near rivers, lakes, oceans, and other bodies of water have high water tables. This just means there is a large amount of water pooled beneath the surface of the ground. When the water table is high, there is a greater chance of flooding because water from rain cannot sink into the earth to as great of an extent as in places with a low water table.
Basements in areas with high hydrostatic pressure, which is when the water table is high, are prone to water damage. While concrete seems strong and impervious to water flowing through it, it is actually a porous material. Its mixing process results in a large number of tiny air pockets that allow water and moisture to pass through the material. While trace amounts of moisture are not a problem, water can physically pass through the concrete and drip through the walls, leading to mold and mildew build-up, as well as damaging your home and possessions.
The best way to prevent this type of damage is by using a concrete sealer. If you use an acrylic sealer, the water will just seep through and push the sealer off the surface from within the material. The acrylic sealer will bubble and flake and water will still drip into your basement. The better choice is a penetrating sealer. These sealers will penetrate past the surface of the concrete to react chemically within the material. The chemical reaction not only increases the concrete’s density and strength, but it also fills in the pores and hairline cracks that allow the uninhibited passage of moisture into the concrete. Without a free network offering passage throughout the concrete, the water will have nowhere to go, backed up outside of the surface and barred from entrance. Only then will your concrete’s safety be improved and protection achieved.
One of the most compelling reasons to use a concrete sealer is to help improve the water resistance of the slab. While many manufacturers and distributors claim their products will waterproof your concrete, there is actually no way to guarantee this. If you read about such a guarantee, the company is not being entirely honest with you. Certain products offer better odds of water resistance, but no product can absolutely guarantee that their product will entirely waterproof your concrete for life.
Once you ignore the grandiose claims of most companies, you can start to figure out which type of concrete sealer offers the best level of protection from water. There are two types of sealers: topical and penetrating. The topical sealers will leave a film on the surface of the concrete, but it will not give your concrete as much protection from water and other moisture. For one, water can seep into the material from underneath, traveling through the concrete to cause the protective films to bubble and flake. These surface sealers are more like raincoats for your concrete, offering only minimal protection.
The better option to improve water resistance would be the penetrating concrere sealers. Silanes, siloxanes, silane/siloxanes, siliconates and silicate/siliconates will all function to lock out water and other harmful moisture. Once your concrete is protected from excessive water damage, you don’t have to worry about problems like mold and mildew build-up, as well as the dampness and mustiness that can plague unprotected basements. Increased water resistance also improves the structural integrity of the concrete, as water can leech from the material vital minerals crucial to its strength and durability. If water damage is something you want to prevent, you should use a penetrating sealer, which gives you the most comprehensive protection.
Our Take: By using a penetrating, impregnating sealer that densifies and hardens concrete and also provides a hydrophobic surface barrier you can ensure a fully waterproofed substrate. One of our favorite concrete waterproofers is Lithi-Tek 9500. This sealer is an invisible, penetrating concrete sealer that will not only densify concrete, but it will waterproof and help to prevent deleterious organic growth.