As profiles frequently change and the natural content can have variations over the years, it is difficult (and bordering on impossible) to find bricks identical to those originally installed on your house, especially if it was built several decades ago. In the absence of such a lucky discovery as a perfect match, you're left with two options - accept that they will look different or refinish the entire house.
Don't paint bricks!
Painting is a tempting solution for a quick and relatively inexpensive face lift; however, it is not a solution that will last.
Traditional paints form a vapour-impermeable layer on the facade of the house. This is not a good thing. The problem lies in the fact that bricks are porous, and they need to remain so. In order for them to function properly, there cannot be a 'waterproof' coating applied that prevents them from drying to the exterior.
Bricks will absorb moisture from the interior of a home and they need to be able to expel that moisture; applying paint to the exterior will cause the paint and masonry to lift, peel or crack. Beyond just aesthetics, moisture trapped inside a brick facade can also affect the strength and integrity of mortar, putting the entire wall surface in jeopardy.
Mineral paints compatible with masonry:
There are brick-finishing products on the market that are suitable for masonry, they just won't include latex or silicone.
Though they aren't as common in the North American building industry, paints and dyes based on silica have been used successfully in Europe for more than 50 years. There is one North American manufacturer we know of that meets German industry standards, a company called PermaTint. If anyone stumbles over another similar brand please let us know in the comments section below.
Refinishing bricks and masonry - before and after © Perma Tint
How it works:
Rather than forming a coating on the brick, these waterborne mineral products generate a chemical reaction that permanently binds them to the substrate. These silica-based products, which are biocompatible with brick and stone, are therefore absorbed by the mineral surface to which they are applied. Since water vapour evaporates naturally, the life of the building and the aesthetic finish are protected.
The pigments of these paints (natural inorganic iron oxide) are unaffected by UV rays; they resist frost and prevent the formation of fungi and molds. The paints and dyes should offer you a maintenance-free service life of 20-30 years.
Silica paints and dyes are odorless, non-toxic and do not contain any volatile organic compounds (VOCs). In addition, they are incombustible and therefore healthier, but also safer to work with. It can be applied to any masonry product, including the joints and mortar.