Chimney repair in Broomfield.

1. Crowns.

   The crown is a concrete slab covering the head of the masonry. Water runs off it instead of into the brick and the flue, and nothing else on the chimney is exposed to as much weather.

   In January a Broomfield day averages 18.9°F at the low and 46°F at the high (NOAA), so a hairline crack takes in water and widens as it freezes. A hairline crack can be sealed. Once a crown is crumbling, or has parted from the flue tile, sealing no longer helps and the whole slab must be rebuilt.

   

2. Caps and screens.

   The cap shuts out birds, squirrels, rain and snow, and its screen doubles as the spark arrestor. Section R1003.9.2 of the model code (IRC) limits the screen openings to 1/2 inch at the widest.

   Metal caps rust, and wind and hail bend them. Dents, loose fasteners, rust at the seams and a screen that has sagged or clogged are what to look for after a storm.

   

3. Flashing, where roof meets brick.

   Flashing is the weatherproof joint between chimney and roof. Snow stacks against the uphill face and melts slowly, so any lifted edge or worn sealant leaks right at that line. Indoors, the earliest sign is often a brown mark on a ceiling or on the attic wall by the chimney.

   

4. Brickwork and its joints.

   Mortar is the sacrificial part: it is meant to erode before the brick. When joints open, water works in behind the brick face, and every freeze pushes off a flake, a failure called spalling.

   Tuckpointing means working new mortar into joints that have eroded, before the bricks start to shift. A brick that has cracked through or flaked deeply is cut out and replaced.

5. Firebox.

   Flame and heat land directly on the firebrick and the mortar between. Gaps and cracked brick pass that heat to the structure behind the firebox, so fixing a small gap protects the wood framing around the fireplace.

   

6. The flue liner.

   The liner runs up the middle of the chimney and carries smoke and heat out of the house. When a tile has cracked or slipped, or a metal joint has rusted open, heat can reach the framing and gas can reach the rooms, yet the fault is usually invisible from the firebox or the roof. Finding it takes a camera run up the flue, which is included in a Level 2 inspection. With 2002 as the median build year, most Broomfield liners are in their third decade.

   

7. Framed chases and their covers.

   Many newer chimneys are a wooden box finished like the house, with a metal cover on top. When that cover rusts through or sags, rain pools on it and runs down the inside of the chase. A cap and screen on the flue, plus a cover that sheds water, keep the inside dry.

   

Get a repair looked at