The crown is the sloped slab of concrete or mortar across the top of a masonry chimney, surrounding the flue tiles. Its job is to shed water off the top and away from the brick. A good crown overhangs the chimney walls with a drip edge, slopes outward, and has a bond break around the flue so the tiles can expand without cracking it. Many crowns in North Jersey were built with none of those features, out of plain mortar troweled flat.
That kind of crown cracks within a few years and then freeze-thaw does the rest. Water enters the cracks, freezes, widens them, and eventually the crown breaks apart and the top courses of brick start absorbing water directly. Asset Roofing & Chimney repairs crowns that are still structurally sound by sealing cracks with a flexible crown coating, and replaces crowns that are crumbling by removing the old material and pouring a new, properly detailed concrete crown.
You usually cannot see the crown from the ground, so the first sign is often a leak or a chunk of concrete in the gutter. If your chimney has never had its crown looked at, it is worth having checked, especially before winter. A crown repair is far cheaper than the brick rebuild that follows a crown left to fail.
What chimney crown repair from Asset includes
- Assessment of the crown, the flue tiles it surrounds and the top courses of brick
- Crack sealing with a flexible, waterproof crown coating when the crown is sound
- Removal of failed crowns and replacement with a properly detailed concrete crown
- Overhang with drip edge and outward slope on new crowns
- Bond break and sealant around flue tiles to allow expansion
- Rebuilding of deteriorated top courses when needed before the new crown
- Cap installation or reset on the finished crown
