Chase tops and storm collars on factory-built chimneys
A factory-built chimney that rises through the roof inside a framed chase has two weak points. The chase cover can rust, dish in the middle and hold water. The storm collar, the metal ring sealed around the flue where it passes through the cover, can loosen or lose its seal, letting water run straight down the outside of the flue pipe.
Water that follows the flue pipe down often appears at the top of the fireplace opening or inside the firebox, which makes it look like a masonry leak. Replacing the cover with one that is sloped or crowned so water sheds, and resealing the collar with a high-temperature sealant, usually ends it.
Where an older brick chimney is still standing
Where an older masonry chimney remains, the top is the usual entry point. A flat mortar crown with no overhang lets water run down the brick and crack the crown over time, and a flue with no cap takes rain straight into the firebox.
The California Residential Code requires a masonry chimney cap with a drip edge and a bond break around the flue liner. A crown rebuilt to that detail, with a stainless cap above it, deals with both problems at once.
Tell us whether the fireplace vents through the wall or the roof, and where the water shows. Tell us what you are seeing and ask for an estimate.
If water has reached a gas fireplace
Water inside a gas appliance does more than stain. It rusts burner trays, valves and ignition parts, and a unit that has been rained on from above may light unreliably afterwards. Leave it off until the leak is fixed and the unit has been checked.
Water can also upset a gas valve's seals. If you notice a gas odor after a leak, walk out of the house and make the call to the gas utility from the yard or street.
What to write down when the leak happens
The details that speed up diagnosis are simple. Note the wind direction and how hard it was raining, how soon after the rain started the water appeared, and exactly where it showed.
- 1Wall stain near a vent cap after wind-driven rain: the wall termination.
- 2Drips at the top of the fireplace opening in steady rain: the storm collar or chase cover.
- 3Water on the firebox floor of a masonry fireplace: an uncapped flue or cracked crown.
- 4Staining on the ceiling next to a brick chimney: flashing.
What sets chimney leak repair cost in Manhattan Beach
Which component has failed, whether it is a stock part or custom-made to the chase size, the height of the house and roof access, and whether water has damaged framing, drywall or the appliance. Custom chase covers and replacement parts for a specific fireplace model can add lead time as well as cost.