A lot of chimneys we see have cracks in the crown mortar which can allow water to enter the chimney structure.
When a brick chimney is built the masons use a type “S” or “N” motor which is good for building the chimney structure.
The problem with most chimneys is the crown or top of chimney is formed with the same mortar they were using to build the chimney.
The proper mixture for a chimney crown is Portland cement product. I have almost NEVER seen this used, most of the time it’s the regular brick mortar mix.
The problem is regular mortar will get shrink cracks about day 10 of drying. If built during summer it can happen quicker.
This is a standard chimney we see.
this is what they look like after years of exposure to
sun, rain, freeze thaw cycles etc. the rust is from cheap
Here you see the mortar missing on crown.
We use a product called Crown Coat. Its a flexible product that sticks to the mortar and allows the crown to expand and contract as needed during the heating of the day.
Your chimney has 5 sides.. 4 vertical and 1 horizontal “side”.
Think how the sun moves across you home during the day. The chimney can get sun on one side in the morning, the top around noon and the other side in the afternoon. The crown is the only “side” attached to all sides.
Crown repairs only start around $225.00, adding power washing and water repellent treatment ups the price to some $600 or so. Call the office at 919-772-8110 to get more info.
chimney water repellent and water damage repair in Raleigh NC.