The steps needed to seal brick are similar to those needed to apply paint. First, the area to be sealed should be cleaned and prepared. Then, the sealant should be applied smoothly and evenly in one or several coats, and little clean-up should be required if the brick has been prepared correctly. The sealing process is very similar for brick walls and for brick pavers.
Several different products can be used to seal brick, but the most common are derivatives of silicone that are absorbed into the structure of the brick. For these sealants to be effective, they must be able to penetrate into a brick surface. Dirt, paint residue, or other foreign substances must therefore be removed in order to effectively seal brick. If some pieces of brick or mortar are loose, they should be brushed away and possibly patched, as needed, before sealant is applied. Any mortar used for repairs should be allowed to dry completely.
After a surface has been cleaned, it should be allowed to dry thoroughly before sealant is applied. It is always advisable to check the weather forecast when planning to seal brick as the sealant should be applied to dry brick and should not be exposed to moisture until it has fully dried. As part of the preparation process, it is advisable to mask off windows, doors, and other pieces of trim or decorative elements. It may be wise to protect plants from overspray, as well.
Each product used to seal brick has somewhat different technical specifications. The directions for a product should always be followed. Many products can be applied either with sprayer or with brushes and rollers. Sprayers typically allow brick to be sealed more quickly, but may not allow for precise work in small spaces, and some homeowners may not wish to purchase a sprayer for a single task.
The application instructions for sealants vary as well. Some call for multiple coats of different thicknesses, usually starting with a light coat and then adding one or more thicker layers. Others may simply require one coat or may have additional special application instructions. When applying sealant, care should be taken to apply an even and uniform coat. Sealant is typically absorbed into brick and is invisible once it has dried, but a careless application can leave permanent stains.
Any excess sealant that spills or drips should be cleaned up quickly. Careful preparation work should minimize the amount of cleanup necessary. In the event that cleanup is needed, however, the specific instructions for a particular sealant should be followed.
