Concrete densifiers are applied to a concrete surface to fill the pores of the concrete and make it less permeable to stains. They are a water-based chemical solution that penetrates the surface of the concrete and reacts chemically with the concrete to increase its density and strength. Densifiers can be used on both polished and unpolished concrete.
Mixing concrete is a more challenging process than many people realize. Concrete is a mix of cement, aggregate, and water. If the proportions are even slightly off, the resulting concrete will deteriorate faster than a properly mixed concrete. Too little water in the mix can result in concrete that is difficult to spread, while too much water in the mix can result in shrinking and cracking as the concrete hardens.
When concrete is poured, excess water rises to the surface of the concrete. Called bleed water, it makes the surface of the concrete weaker than the core by carrying fine aggregate to the surface. Densifiers help address this problem by helping the materials bind better, which strengthens the surface. However, concrete densifiers cannot improve a sub-standard concrete mix.
Concrete is a naturally porous material, which make it susceptible to staining from spilled liquids. For many commercial buildings, concrete stains on sidewalks and interior concrete surfaces are a constant battle. The use of a densifier tightens the pores for a harder and more durable surface.
When used with polished concrete, densifiers help achieve a better shine. The process of polishing smooths out the peaks and valleys of the concrete, but if the concrete isn’t strong enough, the polishing process can remove small chunks that ultimately reduce the shine. A densifier applied to the surface helps fill the pores and create a smooth surface for a better shine.
Concrete densifiers are one of several ways to protect a concrete surface from staining, but it’s always best to consult a professional to ensure the right product and right approach are used when treating concrete.