Do I need a special kind of mortar for this repair? I have an oil furnace and where the flue goes into the chimney, it's no longer intact. Any special procedure to fixing it other than just getting it in there?
I decided to not use cement for a quick fix. As I was moving the stovepipe to look around, one of the sections just separated. That, with the earlier suggestion of a liner got me looking around. I ended up getting a liner kit, thinking I'd make it safer, and more efficient. What a PITA!! I measured the top of the chimney but didn't realize the size got smaller where it went through the attic, so I buggered the insulation on the liner up a bit in the tight section.
Another bump in the road was the chimney itself. I believe I could have kicked it a few times and knocked it off the house...Nearly all the mortar was disintegrating and a simple patch job wasn't going to cut it. So, I learned how to lay brick. Not the prettiest, but pretty solid. I did manage to lay one of them inside out though. LOL!
Replaced all the stovepipe as well. I'm going to make a collar to cover up the hole, finish taping up the flue joints, and be done with it. Thanks for the suggestions.
I would suggest getting some cement, not mortar and creating a proper crown at the top of the chimney to keep water from getting in the hole and recreating the original problem with the mortar joints. Water will get in the holes, migrate down and during the freeze thaw cycle bust the mortar out of the joints. This will also cause the brick face to bust off.
We had a similar issue. Single wall pipe going into a brick chimney with no liner. The brick would sweat in cold temps and caused extensive roof damage over the years. We re-roofed the house, and then dropped a linner down the chimney, hooked it up to a new chimney pipe (new furnace also at the time). With the new liner all is staying dry.
I added a cap. Stupid me ordered the wrong size(too small) though. I had to get a piece of sheet metal from lowes, cut it to size, cut a hole in the middle, then secure it to the brick. Then I had to secure the cap to it...not too pretty, but it works.
I bet it look fine from the yard, it looks good from my yard.
If you ever replace the roof, build a saddle for behind the chimney. That works but with dirt and debris setting against the chimney will hold water and cause the flashing to rust if left long enough