Chimney Rebuilding in Denver, From the Top Down

Brick runs deep in Denver. After a fire in April 1863 destroyed more than 70 buildings downtown, the city passed an ordinance requiring brick or stone construction, and brick stayed the material of choice for generations of homes. Today about 61,000 Denver homes were built in 1939 or earlier, according to the Census Bureau. Many of their chimneys are 85 to 130 years old, and some were never rebuilt above the roof.

The top of a chimney takes the worst of the weather: about 135 freeze-thaw days a year, wind, and snow that sits on it, 49 inches a year at the Denver-Stapleton station and 92.8 in Boulder by NOAA's normals. That is why rebuilds usually start at the top. In the Denver area, relaying a few top courses typically costs $1,000 to $3,500; the whole stack above the roof, $5,000 to $15,000 or more.

Signs you need this

• Bricks near the top that move when pushed by hand
• The stack leaning or pulling away from the house
• Mortar missing from most joints, not just a few
• A crown broken into pieces with loose brick under it
• Earlier patches that keep failing every winter

How we do it

1. Find sound brickWe inspect and decide how far down the damage goes, then write down the price for that scope.
2. Check permits and reviewIf your home is a landmark or in a historic district in Denver or Boulder, exterior work may need review first. We check and help with the paperwork.
3. Take down and rebuildBrick by brick to sound masonry, with matched brick and mortar and new flue tiles where they are needed.
4. Finish the topA poured crown with an overhang, new flashing and a cap, so the new work stays dry.

How far down does a chimney need to be rebuilt?

Only as far as the bricks are loose or the mortar has failed. On many Denver chimneys that is the top few courses, where freeze-thaw and missing crowns do the most damage. When the whole stack above the roof is loose, leaning or badly spalled, the rebuild goes down to the roofline.

Rarely, the damage continues into the attic or down to the foundation. That work is priced at the inspection, after we can see the condition of the chimney inside the house.

What about historic homes in Denver and Boulder?

In Denver, the city's Landmark Preservation staff and commission review the design of exterior projects that need building or zoning permits at individual landmarks and in historic districts. In Boulder, every exterior change to a designated landmark or a property in a historic district needs a Landmark Alteration Certificate.

Boulder's historic preservation page also notes a 20% state tax credit for qualifying rehabilitation of local landmarks and contributing buildings. On these homes we match the brick, the bond pattern and the mortar color, and we use a softer mortar suited to old brick.

Should I rebuild a chimney I never use?

Maybe not. If the fireplace is not used, taking the stack down below the roof is often cheaper than rebuilding it. If you would like to use it, a rebuild combined with gas logs or an insert gives you a fireplace that can also be used on Action Days. We lay out the choices with prices side by side.