Chimney fires are very dangerous for you, your family, and your home. Chimney fires can be cause by cracks in the bricks of the chimney, creosote build up, blockages, and a few other things. They have to cleaned out every year as least once and if used heavily, perhaps twice. This way there will be no dangerous flammable build up that can ignite when the flames get too high or is burning too hot. Creosote build-up is one of the leading causes of chimney fires.
You should have a cap over your chimney to help keep water out as well as help prevent debris and small animals out as well. Birds and squirrels will often build a nest in a chimney. A chimney cap also help to keep flying hot ash from escaping and starting a fire on your roof or in your yard. You have to check the chimney for cracks in the cement. Over time the cement edging around a chimney can deteriorate and will begin to break apart. There is flashing underneath the shingles where the chimney meets the roof. This is to help keep water from running into the home. When the shingles are loose, the flashing can be exposed to water.
When there is creosote build up, it is all over the inside walls of the chimney and it is very flammable.
Although you can find ways to clean the inside of the chimney yourself, it is a difficult and nasty job. You also may not have the knowledge necessary to spot possible problems with the construction of the chimney. Most people will use a professional chimney sweep who can also make repairs if necessary. This is probably the easiest and safest way to keep your chimney cleaned and maintained. If your chimney has to be repaired because of cracks, you can not use the chimney until it is dry.
If you have ever had a chimney fire, you know it can be more than scary. The noise can sometimes sound like a train going through your house. Flames can be coming out of the top of the chimney on the roof a couple of feet high and it can shoot out every direction. It will put smoke in the air outside and possibly inside as well. Some chimney fires will simply burn themselves out. When you are not that lucky, it can cause the roof to catch on fire or the if there are any undiscovered cracks inside the chimney, it can catch the walls inside the home on fire too. Your home could be in flames in minutes all because your chimney was dirty or damaged.