Today I’m going to be rebuilding my chimney stack. At the end of last winter, we noticed it was leaking so it’s time to fix it before the rainy season starts again.
Last winter, we sprung a little bit of a leak coming down from the chimney. You can see the water rings that formed.
A big storm came through the area recently, so I tarped up the chimney until I could make the repairs.
I set up the ladder and climbed on the roof to remove the tarp.
It was only being held by a couple ratchet straps so it was easy to remove, however a bunch of water did get trapped in the tarp from the storm.
This is the chimney stack. Some of the wood siding was in acceptable shape, but most of it was junk. The water was actually seeping through the spongy wood. This corner was the worst, but you can see how soft it was as I mashed through it with the hammer.
It was time to just start ripping into it. Using a hammer and a pry-bar, I tore the wood off the frame. It was actually a lot more difficult than I thought it would be.
I removed the chimney cap so I could eventually pull off the crown flashing.
These 2×4’s needed to be pulled off so I could remove all the siding.
I continued pulling off the rest of the siding. After ripping out what seemed like a million nails, it was finally open.
Before starting to rebuild the stack, I wanted to clean up the area and remove all the debris from the roof. Not only would it be easier to work, it makes it a lot safer as well.
I spent a few minutes and measured out all the dimensions of the frame.
I purchased some siding from the home center. Unfortunately, the stack was just big enough that I needed a whole 4×8 sheet for each side. Using my cordless circular saw, I cut them down to length.
The two smaller sides were narrow enough to cut on the table saw. I ripped them down to width, removing the overlapping edge.
Those two small sides also needed an angle cut to contour the roof line. I marked and cut them out.
The longer panels were too wide to rip down on the table saw, so I drew a line and cut it by eye using the circular saw.
Once those were cut, I ran them up on the roof and placed them next to the chimney stack.
I put the first panel in place and then scribed the top using a black sharpie.
I made the quick cut and then put it back in place. Since it was a perfect fit, I screwed it in place.
I did the same thing for the other three sides: Scribe, cut, screw.
I measured and cut a few 2×4’s to recreate the boarder along the top of the stack for the crown flashing to attach to.
These didn’t need to have mitered ends, it’s just what was there before.
After screwing them in place, I replaced the flashing and screwed it down. Then I could reinstall the cap.
For a little decorative effect, as well as help seal the edges of the siding, the chimney had 1×4 trim.
To cut the 1×4 to the correct angle, I used a scrap 2×4 and scribed it with a sharpie. After cutting it fits great.
Then I flipped that board around, and cut it to length. When both boards were done, I screwed them into stack.
And again, I did the same exact thing on the other three sides.
To waterproof all the seams, I used a silicone caulking. I sealed up anywhere that two piece of wood met, as well as covered the screw heads.
I had already checked that my metal flashing was in great shape, but I also put a heavy coat of Henry’s roof patch, just for good measure.
I chose a good exterior grade primer and applied a heavy coat. I made sure to get it into every nook and cranny.
The final step was to apply a coat of paint. We don’t like this color, but until we paint the rest of the house, it would look weird with anything else.
And that’s it. A completely new chimney stack.
My Project Tools
CORDLESS CIRCULAR SAW