Question: Hello, we recently purchased and are renovating/restoring a large brick 1897 house. It has 8 fireplaces (all brick and originally with gas lines run to each). We are interested in installing gas logs and have questions about venting. Since the chimneys are quite old what is the best method of venting? Do you run independent pipes? If so how are they discharged at the top? Answer: It depends on the condition and size of the chimney flues and the appliances that you intend to install. If they are regular vented gas logs, it may be possible for two to share the same flue (if that's what the wood fireplaces are doing now). If the chimney is not smoke-tight and deteriorating in other ways, then a liner would be in order. A minimum 8" round liner is required for most gas logs, and it may even have to be larger depending on the fireplace opening size. If you are using sealed gas fireplace inserts, the lining can be flex aluminum, which is much smaller. These can all terminate at the top of the chimney structure by simply extending through a custom flashing made for the chimney top. There are other decorative options also. Sounds like you need to have an inspection done by a chimney professional...in fact, get at least two or three separate opinions before proceeding.