An experienced home inspector knows that this older Pleasant Hill house chimney was constructed without the use of reinforcing steel and that brick mortar is deteriorating.
Brick and mortar chimneys have three common failings – The first is that with age, the acids in the air (pollution) react with the concrete mortar joists to produce Calcium Sulfate, which deteriorates brick mortar joints.
The second is that with rain, the degraded mortar may dissolve somewhat, leaving a more porous crumbly sandy mortar.
Third is the freeze-thaw damage to concrete or mortar. Water is absorbed into porous materials and if the temperature drops below freezing, the water may freeze into ice. The volume of water increases when it freezes and can crack bricks and mortar.
Add the fact that chimneys built prior to 1959 probably don’t have reinforcing steel making this chimney susceptible to toppling during an earthquake. This is a safety concern, a home owner’s liability and doesn’t meeting building requirements.
We’d recommend to a home buyer that a licensed chimney specialist review the old chimney prior to buying the house.