Water damage prevention

Water damage causes more problems in a masonry chimney than fire. Sound odd? Think about it. All the materials used to make up your home have protection from the roof and eave. All except your chimney. There, on top of your roof stands a brave chimney. So brave it stands constantly exposed to rain, snow, freeze and thaw. Month after month it is tortured by mother nature.

Materials such as brick, mortar, tile, steel and cast iron make up the construction of the masonry chimney. All of these materials can suffer accelerated deterioration as a result of prolonged exposure to water.

When exposed to the freeze and thaw process, masonry materials deteriorate quickly due to the moisture that has penetrated into them. This freeze and thaw process, which expands and contracts the materials, puts stress on your masonry chimney also causing damage. Water will also rust steel and cast iron in the chimney and will weaken and eventually destroy the metal parts.

How to repair Crumbling Chimney Mortar





How to prevent water damage

The first and easiest step in preventing water damage to your chimney is to install a chimney cap. Chimney caps or rain caps are one of the most inexpensive prevention measures. Masonry chimneys have one or more flues that will allow rain to enter the inside of your chimney. By using a chimney cap, water is prevented from running into the flue and causing damage. A cap with a screen will also keep birds and animals from nesting inside the chimney. Chimney caps also work as a spark arrestor. The screens will prevent sparks from landing on the roof or other nearby combustible material.

Replace or repair a damaged chimney crown.

    The chimney crown covers and seals the top of the chimney from the flue liner to the chimney edge. It is designed with a tapered edge so water is deflected away from the chimney flue. Most masonry chimneys are built with an inadequate crown from mortar that is not designed to withstand years of weather exposure. As this mortar breaks down it exposes the chimney flue to water which will cause damage to the flue.
    By replacing or repairing a damaged crown you will be preventing possible damage to your chimney.

How to repair a Chimney Crown

Repair or replace flashing.

    The flashing is the seal between the roof and the chimney. The flashing prevents water from leaking into the living area along side the chimney where it can damage ceilings, walls or cause structural damage.

How to Repair or Install Chimney Flashing

Waterproof your chimney.

    Most all masonry material is porous and will absorb water easily. Brick can act like a sponge which will allow water to enter the chimney. Loose or crumbling mortar joints will also increase their tendency to absorb water.

    Waterproofing products have been developed which allow your chimney to breathe out, but not in. Therefore, water that has penetrated the chimney, or moisture that originated inside the chimney is able to escape while the waterproofing material prevents water from entering from the outside walls.

Water Damage Preventer 

Water damage is usually a slow, subtle process. Problems are usually not noticeable until it has become quite serious.

Initially, water prevention measures may cost a few dollars, but will save you a major expense in chimney replacement in the future. It will be a wise investment in your home.

I have tried everything and I still have a leak?? 

If you have found that water damage has already begun deterioration of your chimney flue, and the above suggestions are not the answer, consider relining your chimney with a flexible stainless steel chimney liner. A stainless steel liner will stop further deterioration of your chimney flue while helping your heating appliance run more efficiently.


Purchase a Stainless Steel Flue Liner Chimney-Liner-Central.com Home: The DIY Chimney Repair Resource