Vacuum the surface of the brick wall or floor. This will remove the dust and debris that will cause problems with the sealer attaching to the wall.
Place drop cloths around areas that may have splatter or dripping. This will protect furniture and plants that may be exposed to the sealer which can damage items.
Use the 2-inch paintbrush to reach hard to get areas or places where the roller will not fit. This is also a particularly useful practice to keep the sealer off of grass and plants. This product can cause leaf damage and even death of the plants.
Pour 2-inches of sealer into the paint tray for the roller. Carefully place the roller into the sealer and roll until the roller is covered. The first attempt will take a few more rolls that subsequent applications to the roller.
Apply the sealer to the surface. Use slow gentle motions applying the sealer since it is thin and will splatter. The walls will require even greater care since there is the potential of dropping sealer.
Allow the sealer to dry overnight. Apply a second coat in the manner as the first coat.