Chimney Rebuild Progress

One of the projects on the 2025 to-do list was rebuilding at least one of the two chimneys on the east wall of the house. A couple weeks ago, I started that project. 

The chimneys, which were previously rebuilt in the half-assed fashion that's typical of most of the prior "rehabs" the house has undergone, are in rough shape. The chimney I chose to tackle is the northernmost of the two; the cap was cracked, the unnecessary parging on the yard side of the chimney had delaminated and allowed a ton of water into the wall, and the roof membrane "flashing" was absolute trash.   

Here's a better look at some of the problems:

See the leafy thing in the bottom lefthand corner of the pic below? Vegetation isn't supposed to be growing out of walls, let alone 18' up the wall. This is how the parapet vegetation in the bottom righthand corner of the pic starts out. 

Once I really took some time to assess the chimney's condition and knowing some major brick surgery was going to be required, I decided to first repoint a section of the wall below the chimney and parapet. I feel a whole lot better about tearing out and rebuilding sections of parapet when there's a solid area beneath it. 

Repointing a lower section first also gave me some time to figure out how to erect another level of scaffold, which I needed to get up to the parapet and chimney elevation. My scaffold just barely fits -- I had to cut some tree branches to make it happen -- in this little corner between the house and the porch, and getting that 4th set of scaffold frames up to the top is no picnic.

Then it was time to start the deconstruction. I figured it would go fast; the walls with rotten, waterlogged mortar come apart without any real effort. 

I'd never given it much thought, but I realized that these chimneys have two flues: the one on the left goes to the basement (finished, livable space when the house built in 1878) and would have served, presumably, some sort of wood or coal burning stove or furnace; the flue on the right goes to the fireplace on the main floor. 

I also discovered that the flue to the main floor fireplace had a liner...except it only goes halfway down to the firebox, which makes it pointless. Remember the comment about half-assed work...example #381. 

The stainless steel liner comes in 4' sections, but I couldn't for the life of me bust this section free. It wasn't until I worked my way down a little further than I could see why: the sections had been riveted together. 

If you look closely, just above the seem between two liner sections, you'll see a little hole. That's where I drilled out one of the rivets. Unfortunately, there was another rivet on the roof side that I had no way reasonable to get to horizontally. Fortunately, I own a lot of hammers and a lot of long pieces of steel, and I was able to stick some steel down through the top of the liner, catch the rivet, and beat on it until it snapped, allowing me to remove that liner section.  

In that same pic, you can see the top of the wall section I repointed. I'm super, super glad I made the decision to do that before I started this demo. 

I tore out just about everything I could reach and called it quits once I started hitting mortar that was still pretty solid. After a little cleanup, I was able to start rebuilding walls.

I had a hard time reaching some of the first few chimney courses I needed to reset, and on the yard side of the wall the parapet bricks stair step and protrude and do all kinds of things that require a strong attention to detail, so the work started off slowly. 

I will eventually rebuild this entire length of parapet, but for now, I'm just dealing with this section. I use shims to keep a little pressure between the freshly set bricks and the existing bricks while the mortar sets up, and I try to leave myself some strategic places where I can interlock the subsequent parapet rebuilds into this one.

The slowest courses to deal with, by far, are the rows of brick that protrude past the brick in the course below. The easiest way to deal with those rows is to finagle some wood in place to act as a shelf for the bricks until the mortar cures.

After that, it's off to the races (unless I get rained out, like I did today). I decided to cover up the basement flue, because it's not needed and will give me a little more structure to help keep the chimney solid and plumb for many years to come. 

I had to custom cut a bunch of bricks to make it work, but I covered the basement flue with some 1/4" cement board to prevent a ton of mortar from dripping into the basement, and then I stuck 1" steel angle I had laying around under each row of brick that went across the flue. That should be more than enough strength to keep the bricks from sagging, and will allow me to go vertical on a solid base.

Today I finished setting bricks on that layer and was ready to start going up...and then we got about 4" of rain in 20 minutes. Chimney work will have to wait for another day, but the next step will be to get the roof membrane flashed around the chimney.