The crown is the concrete slab that covers the top of the chimney around the flue. Chimney crown repair in Spring Valley seals or recasts it before water gets into the brick below.
Thin crowns made from leftover mortar. They shrink, crack and let water straight into the top courses.
Caulking individual cracks. The crown keeps moving and the caulk lets go.
A look at the crown from the roof. It cannot be judged from the ground. A Level 1 inspection is $69.
The crown works like a small roof for the chimney. It covers the gap between the flue and the outer brick and slopes so that rain runs off instead of soaking in. When it cracks, water enters at the highest point of the chimney and works down through everything below.
The crown is often confused with the cap. The cap is the metal cover over the flue opening. The crown is the masonry slab the flue passes through.
The condition of the slab decides which one applies.
Hairline cracks in a solid crown are covered with a flexible, waterproof crown coating.
A worn but intact crown gets a new bonded surface layer with the correct slope.
A broken or crumbling crown is removed and a new one is cast in place with an overhang.
If the brick under the crown has failed, see chimney rebuild.
A good crown is cast from concrete, not laid from mortar. It is at least a couple of inches thick at the edge, slopes away from the flue, and extends past the brick with a drip edge underneath. A gap filled with flexible sealant is left around the flue tile, because the tile heats and expands and the crown does not.
Many older crowns have none of these features. They are a thin wash of mortar finished flush with the brick, and they crack within a few years.
Water that gets under the crown saturates the top courses of brick. Freeze-thaw cycles then break those courses apart, which is covered under chimney masonry repair. The same water runs down the outside of the flue tiles and into the house, where it shows up as a leak. See chimney leak repair.
A crown repair is a good time to check the cap and the top flue tile. A cracked top tile is addressed under chimney liner repair. Water entering lower down, at the roofline, is a flashing matter. See chimney flashing repair.
The crown is the concrete slab that seals the top of the chimney. The cap is the metal cover that sits over the flue opening to keep out rain and animals.
Yes, when the cracks are fine and the slab is solid. A crown that is broken, loose or crumbling needs to be recast.
Usually you cannot see it from the ground. It is checked from the roof during an inspection.