The Ultimate Chimney Cracks Repair Quiz

Mortar joints between brick and stone on chimneys are likely to start cracking, flaking or washing out after 20 to 25 years. In rare cases, problems can develop earlier, so it's wise to keep a watchful eye on any chimney.

The simplest way to check your chimney is by using a good pair of binoculars from the ground. You will need to climb to the roof or hire a professional only if you notice a problem that needs closer inspection.

Moisture can make its way into the mortar, where it will freeze and thaw in the winter. The freezing and thawing cycles cause mortar to crack and the cracks let in more moisture, which causes chipping and flaking.

People often attach metal objects such as antennas, satellite dishes and lightning rods to chimneys. Metal expands and contracts at differing rates than mortar, causing extra cracking, and wind loads caused by antennas can place additional stresses for which chimneys were never designed.

Old chimneys were built larger in order to accommodate the heat from hotter fires using coal or wood and deteriorate quickly if they are not heated enough. Retrofitted heating units use gas or oil and run much cooler, so they require smaller chimneys or stainless steel liners.

Although a major problem with a chimney can be a fire hazard and a leak can allow combustion gases into your home, the real concern is to catch a small problem before it becomes a major repair or a dangerous hazard.

If you experience a significant earthquake in your neighborhood, you should have your chimney inspected as soon as possible. In 2001, there was a 6.8 earthquake in Seattle and around 50 percent of homes experienced chimney damage.

All masonry chimneys have lead or metal called flashing around them. One end of the material is imbedded in the masonry a few inches from the roof and the other end is positioned under the roofing to seal out rain and snow.

If you detect what appears to be serious damage to outer brickwork, flashing or interior lining of the chimney you should stop and consult with a professional. It may even be illegal in your community to do your own repairs.

One of the simplest steps that you can take to protect your chimney is to install a quality chimney cap. These caps not only help to keep the weather out, they also prevent birds and animals from nesting in or blocking your chimney.

When you burn wood, a byproduct is creosote, which looks like tar so you will need to have your flue cleaned at least once a year. Creosote is highly flammable when it gets hot enough and can cause an extremely dangerous flue fire!

If you are not an experienced climber, a safety harness would be a good idea but covering the fireplace opening is essential. It is never a good idea to work on a roof or other high place without a helper on the ground.

Tuck-pointing is the process of removing flaking, broken and crumbling mortar with a tool called a mortar-raking tool. When done properly you are left with a stable foundation for new mortar.

You can mix a pigment with the prepared mortar before making your repairs. Repairs will not stand out from the old mortar joints when you color with pigment.

You should always try to chisel to of depth of at least one inch to insure that the new mortar will make a good bond and stay in place. Standard bricks are four inches deep, so you do not need to worry if you go a bit deeper than an inch or two.

You are trying to mix mortar that is the consistency of peanut butter, as you want it to stay in place while it dries. Some mortar requires addition of sand while others simply need water.

It is preferable to start with vertical joints before moving on to horizontal joints. Clear away your excess mortar as you go along before it dries on the brick face.

Try to keep mortar damp for three or four days after you complete your repair to promote curing of the cement in the mortar. Properly cured mortar will ensure that your repair will last much longer.

Have your chimney inspected or carefully inspect your chimney for hairline cracks or cracks in the concrete crown. Hairline cracks should be sealed with products designed for that purpose, as mortar is difficult to force into tiny cracks.

According to masonry experts, you should never allow vines to grow over your brick or stone veneers and chimneys. The root system of creeping vines tends to open up or break down both mortar and brick along with holding destructive moisture that will result in damage and premature failure.