How To Seal Acid Stained Concrete

What You'll Need
Paint roller
Paint roller refill (super smooth)
Paint tray and liner
Large brush
Polyurethane sealer

An acid stained concrete floor is wonderful to behold, creating a marble-like pattern on the surface, but in order for it to shine like marble and keep it protected, you have to seal it. The hydrochloric acid solution reacts with the minerals present in the concrete, which in turn picks up carbon dioxide from the air, creating efflorescence—a varied tone of color upon the concrete. This type of decorative concrete overlay is very popular and a good alternative to ordinary concrete.

After you have finished acid staining the concrete, it is time to use a finish sealer.

Step 1: Aerate the Room

Make sure the room in which you are working has adequate ventilation. Open doors and windows, turn on a fan or otherwise ensure that the heavy fumes don’t remain stagnant.

Step 2: Clean Floor

Thoroughly clean the concrete floor after the acid stain has dried fully. There should be nothing on the surface when you begin to seal it.

Step 3: Prepare the Sealer and Paint Roller

Slip the super smooth refill onto the paint roller and shake the polyurethane sealer well. Set up the paint tray with the liner inside and pour a good amount of sealer into the tray.

Step 4: Start with the Periphery

Use the large brush to seal a 3-inch strip around the entire perimeter of the room right up against the wall. This will prevent the roller from brushing up against the wall later. Apply sealer in smooth, even strokes.

Step 5: Seal the Remainder of the Room

After the edge is sealed, start with the point farthest from the exit. When you dip the paint roller into the sealer, make sure you run it over the top portion of the liner to take off any excess. You don’t want drips on the floor. With the brush, go over any bubbles that arise after you have applied the seal. You want the sealer applied uniformly, and you don’t want too much, so don’t rush through it.  

Step 6: Let Dry and Repeat

Let the sealer dry completely then add a second coat in the same manner.

Now that your concrete floor is sealed, it should have a clear protective coating over the acid stain that will bring out the efflorescent pattern. In order to protect the sealer, you can opt to apply a concrete floor wax periodically. This will extend the life of the sealer, especially if there is heavy foot traffic in the room. The floor wax is recommended so as to avoid having to reseal in the future. Sealing a concrete floor can be done in a day with the right tools and preparation. Once you have done it, add it to your DIY repertoire.