How do I repair my chimney?

I have a small masonry chimney that vents my furnace. It is like cinder block with an 8 x 8 clay liner inside and there are chunks missing in spots on the exterior. I want to fill the chunks and resurface the chimney without completely knocking it down. The liner is fine. How do I do this? What is best to use as filler before I resurface?|||There are mortar patching mixes that will handle any small gaps in the exterior block. But ideally you would fill in the 'chunks' with a relatively soft mortar then stucco the entire exterior using aluminum or stainless lath and a latex stucco mix - which you would coat with Thoroseal or similar. This sort of stucco is quite flexible and allows for the normal expansion and contraction of a flue - something that harder materials will not do. If the clay liner is intact there is no reason to install another liner. If not, you will still have to repair the block and possibly re-finish the chimney anyway. So, start with the exterior repairs and work your way back.|||Put in B VENT beside it or upgrade to high efficiencey furnace


don't fix the chimney most codes call for a liner


call heating estimate in!