Do You Need to Seal Concrete After Grinding?

Benefits

• Concrete sealers confer a variety of advantages. The sealer adds a pleasant sheen to the surface, and different sealers can give you an appearance ranging from glossy to satin. They also prevent chemicals, oil, dirt and grease from penetrating the surface of the concrete, making it easier to maintain. Sealers help to minimize wear and stop water and salt from intruding and causing damage. Finally, sealers can help enrich the color and texture of dyed or stained concrete.

Grinding

• Once you've ground the concrete to get rid of the coating and expose the aggregate, you can apply a sealer if desired. You can choose from a variety of products. Acrylic sealers are relatively inexpensive and nonyellowing, while polyurethane sealers are thicker and more resistant to chemical attack. Epoxy sealers are very water-repellent and abrasion resistant; they are much harder than acrylics. Various silanes, siloxanes and silicates penetrate into the concrete and make a chemical barrier that doesn't change the concrete's appearance.

Grind and Seal

• You can apply sealer after you grind and make any other necessary modifications; this kind of approach is called grind and seal. It's cheaper than polishing the concrete, although the expense will depend on the level of the finish. A rougher finish may leave visible scratches even after sealer is applied, whereas a finer finish will be more expensive. Alternatively, the concrete can be polished to provide an even harder though more expensive finish.

Polishing

• Polishing is an alternative to applying sealer after grinding. First, builders apply a densifier to harden the surface of the concrete, then they hone it to the desired level of finish. Finally, the builder may apply penetrating sealers. Whether you want to grind and seal, polish the concrete or simply grind it without sealer depends on your budget, the amount of abrasion resistance you need and the type of appearance you want. Polishing is the most expensive alternative but also the most aesthetically pleasing and durable.