Four Pathways to Chimney Damage

chimney damage from moisture

In the course of your day to day field observations on chimneys, the customer may question how or where damage originated. Sometimes it appears to be a chicken and egg situation. Did the crown wear out and let water in, that started the spalling of brick and mortar, or did the mortar weaken first, letting the crown to settle causing the crown to crack letting even more water in. Or does the mortar hold the bricks together or does it hold them apart? This might be a good debate at a convention but when you’re standing in front of a customer, the bottom line is somebody needs repair work done, and you don’t have all day to explain it to them.

The ability to explain to the customer a logical process how it all happened and the consequences of the lack of repair can be the difference whether you will be doing the repair work or someone else will. The worst case scenario is you don’t make the repair compelling enough for them to take action, without the drama and sales scare tactics many resort to.
Then the situation gets complicated when your customer asks the age-old question whether their chimney is safe to use or not. You, the field technician, are strapped with the concept of how all this happened and try to place a timeline on this, and ultimately what the cost to repair is going to be.

The best way I’ve found to uncomplicate all the many minor or major deficiencies that all of us see, is to break it down into four principal pathways that destroy chimneys. You might have a chimney with more open joints, a worn crown, and an abused rain cover. It comes down to the age-old question of how to eat an elephant; one bite at a time.

The first pathway is latent defects. Those are the defects that were built into the system at the time of the installation, that are usually not seen readily. Although manufactured systems such as prefabricated fireplaces and chimney pipe are designed and built at a factory with an installation guide, many of us have seen where creative uses of the material or poor workmanship have caused material not to be in its ideal condition. With masonry, the list can be long, hearth extensions, firebox limitations, dampers that are inoperative, unparged smoke chambers, and then the liners, open mortar joints, missing liners etc.

The second pathway is from regular wear and tear. This is the time to chimney has spent exposed to outdoor temperature swings, or interior temperature swings have caused a chimney to wear out over of time.

The third pathway is moisture. Of all the pathways this one can create the most havoc. It can be very subtle, and yet totally destroy chimney over a period of time.

The last pathway is from a sudden occurrence. Usually in the form of a lightning strike, an appliance malfunction, high temperature fluctuations like a chimney fire, and other assorted events that appear sudden.

Breaking down chimney degradation into four pathways provides me a way of putting things into perspective for the customer. Because many times you will see all four pathways in one system at one time. Because one deficiency can lead to another deficiency and to another; so, by breaking it down I can explain to the customer how it all happened and where they need to concentrate  their efforts especially when the repair will need to be done in stages, whether monetary or climate considerations.

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