My house that we purchase 3 years ago was built in 1978. When we bought the house, the original fireplace had a cast-iron insert which was very ugly and had a very small fire box. My wife and I hated it and since our new furnace heats the house just fine and energy efficiency wasn't a concern, I removed the insert along with its chimney liner. I later had a chimney sweep out to inspect the situation and he determined that I needed a flue re-line (he wanted to replace the original terra-cotta clay sections with the same) and that my smoke chamber and firebox needed repairs. I decided to go with a flexible stainless reliner and I'm fairly comfortable with the installation steps that I need to do there but my questions are now around the smoke chamber and firebox. I'm pretty sure that there was a chimney fire a some point since the flue is cracked pretty severly in several places and the amount of creosote and ash I found in the smoke chamber. My question is this, does something need to be done along the lines of re-parging my smoke chamber? If you look at these pictures, you can see some clumpy deposits still clinging to the smoke chamber wall. I tried scraping these off with a putty knife but they're on there pretty good. I could break out the cold chisel but I'm afraid that I would distrube the masonry if I do that. Should I just leave it alone? You'll see in the picture that the top 5 back rows of fire brick for the smoke chamber along with the smoke shelf were removed by some previous owner so I need to re-build that but my question there is, what exactly do I finish the smoke shelf with? Should I just finish it smooth with standard brick mortar or do I need to use refractive mortar? You can see at the back of the firebox where the bricks have been removed View attachment IMG_4747.jpg It's a little blurry but you should be able to make-out the lummpy stuff that's on the smoke chamber walls in this photo View attachment IMG_4753.jpg This is the back of the firebox and smoke self area that needs repair View attachment IMG_4748.jpg Another Angle View attachment IMG_4749.jpg Thanks for any help!