Do you have moisture problems in your chimney? If you do, perhaps you are wondering how they happened and how they can be fixed. Some minor leaks may be repaired as a one-day DIY project. Others may require more extensive repair. The severity of the leak determines the extent to which it needs to be repaired.

Moisture problems in chimneys occur because external moisture from rain or other dampness gets into the chimney. This can happen a few different ways:

  • A missing chimney cap can allow rain and snow to blow down into the chimney
  • Damaged chimney crown can allow moisture to get in through the structure
  • Leaks at the sides of the chimney
  • Leaks at the chimney flashing
  • Ground and surface runoff can enter the base of the chimney should it extend below ground

Whichever the reason, know that it can be fixed. It is only a matter of finding out the solution that best fits the particular problem. A certified chimney inspector can help you out with this and once the problem has been distinguished, it only remains for you to fix it.

If your chimney doesn’t have a chimney cap or cover, it is important to get one installed right away. This will prevent moisture as well as rodents and other critters from getting into the flue and causing severe damage. Acting also as a spark preventer as well, chimney caps are very inexpensive and very effective in fixing your moisture problem.

If a damaged chimney crown is causing the leak, a simple sealant will fix the problem. Most chimney crowns are made out of mortar mix which can naturally break down over time thus allowing moisture to get into the flue. Water repellant coatings can also be applied to the crown.

A damaged or improperly installed flashing can also be the source of the problem. It is essential that this is installed correctly otherwise water can leak in through the roof causing significant damage. The best quality flashing is made up of two parts, an L-shaped metal piece called the base that attaches to your chimney and underneath the shingles of your roof, and the counter flashing which overlaps the base and attaches to the masonry joints of the chimney. Having both of these pieces correctly installed will prevent any leaking.

If your chimney is not waterproofed at all, this may be the source of the problem. Years of rainfall battering against your masonry chimney is absorbed like a sponge into the bricks making them incredibly brittle which can lead to a decided lapse in the chimney structure. If you apply a sealant to your chimney, make sure you use one that allows any moisture already in your masonry chimney to get out. The wrong kind of waterproofing sealant will only trap the moisture inside and speed up deterioration.

Whether you are only starting to notice water leaking problems in your chimney or are just buying a new house with a chimney, it is a very wise investment to waterproof your chimney as soon as possible. Doing so will help prevent even greater damage not to mention expense down the road.