Question: I am in the process of adding a fireplace to our home. After much research, I'm still confused. I've chosen to have installed a wood zero clearance firebox that will be fully vented. I've also chosen a gas log set that I want installed. One of the local contractors/installers is reluctant to do the job because the firebox and gas logs are made by different manufacturers. His concern is one of liability - Are the logs certified for the box and vice a versa. Also, if we proceed with the wood box does the chimney pipe need to be 12'' pipe? Or can a smaller pipe be used? Does this vary based on the manufacturer of the pipe? Answer: It is fine to install a VENTED fireplace from one manufacturer and gas logs (vented or unvented) from another. The fireplace should be installed as per the manual...using the particular chimney pipe that is designed for it. Most all pre-fabs are certified for use with MOST fireplace logs. The exception may be Heatilator, who does not like people installing vent-free logs into their fireboxes...although this still may be technically legal and safe. The pipe MUST be made by the same people who make your box.