Chimney Maintenance

On a house that I am currently rehabbing I was on the rough recently and I noticed that the interior mortar on the chimney is falling away. A friend of mine recently tried to purchase a OO home for himself and the inspection did not go through. Our HVAC contractor said he could put a Flu sleve inside and it would take care of the problem and cost around 450.

Has anyone else encountered this problem? If so how did you fix it and how much did it cost?


The best way for me to discribe chimney repairs is relate it to old car restoration.

What happens with chimneys is they basically rot. Yea, you read that right, water gets in through the mortar joints that are exposed to weather. The water works it’s way down and into the rest of the chimney, it cracks the flue liner due to freeze thaw cycles, and the mortar deteriorates over time. Pulling one of these things apart is like doing rust repair on and old car. Because the damage starts from the inside and works OUT, you never know the full extent of damage until it’s pulled apart.

Lining the old flue is the way to go. A stainless steel liner is installed and it makes the chimney usable again. To re-do a clay flue the chimney is basically dismantled. BIG MONEY= THOUSANDS. Relinning the flue won’t fix the mortar joints though. This requires repointing. This can actually be done by you. Grind or chip out loose mortar and using a hawk (flat metal square with handle on bottom, like plasterers use) slide new mortar into joints and finish with joint tool, or you can use a mortar bag, which looks like a big pastery bag that cake decorators use. Fill it with mortar and sqeeze the bag, the mortar flows out the nozzle and into the joint. EASY!

pete thanks for the info.

I figured that I could do some of the re-pointing myself. It’s however, the mortar in the middle of the flu that I can’t repair. However, you say the liner will take care of this?