Painting the brick on your chimney is always, without a doubt, the beginning of a painful, time consuming process for any homeowner who decides to take the painting plunge. Say you aren’t too fond of your brick color or the brick on a portion of the home is starting to look less than desirable, it may seem reasonable to simply slap up some paint on top of it and call it a job well done. What homeowners don’t realize is that their freshly painted chimney immediately starts to deteriorate as soon as the paint has dried, and every rainfall only speeds up the process.
In brick there is naturally found a small percentage of moisture which moves in and out of the brick’s pores. When you paint the brick you block the pores so that the moisture has difficulty leaving. Although it may seem like you are preventing water from damaging the brick at all by blocking the brick with paint, what is actually happening is much worse. This moisture trapped underneath this layer of paint will slowly but surely make its way through the paint. This causes hairline cracks to appear in the paint which allow external water from rain or snow to enter the picture. This water is trapped beneath the paint which actually causes damage to the brick itself! Now not only are you dealing with unattractive, peeling and cracking paint, you also have a structural issue in that the integrity of the brick has been compromised.
There are many options you can take to improve the look of your brick without painting over it. For brick that has been stained, say by rust, dirt, etc., using a brick cleaner is a cheap restoration. Although in years past muriatic acid was the way to clean your brick, there are now safer cleaners available on the market that are less harsh than this acid which can actually stain the brick further when being used. The ChimneySaver Brick and Mortar Cleaner is a product that my servicemen use, especially on harsh chimney stains which can come from an aluminum cap rusting or a black painted chimney caps.
If the reason you are painting over your brick is because it is chipping off or breaking or the mortar joints are falling out, do not paint the chimney! Painting the chimney will only speed up the rate at which your chimney deteriorates. If this is the case, consult a professional to give you an estimate for repair on your chimney.