Question: I'm a laid off road builder who enjoys my winter time off; tinkering and doing winter projects in my garage. Spent several winters with my old top feed belly pot we shared a lot of cords of wood,along with to much sheet metal and pop rivets..she had her day. Last spring re-roofed house and garage and to my dismay, her and her stove pipe were the last to be loaded on the ten yard dumpster. A couple years prior I purchased a used insert (like new) and was thinking of installing it in the garage. It's quite nice cannot see a brand name, glass doors, screen, baffle and blower in unit with a bottom face return for cold air. I am handing at most things but here comes my questions? I would like to cut whole in garage and am capable of pouring outdoor slab to place it on. That would save me space and avoid cutting hole in my new roof for stack; also avoiding the high cost 600-750 $ for the metal parts I have been quoted. I guess my question comes to this.....How do I build the fire place and stack off and around it? What would be economical but safe? And how far should the chimney clear off the side of my garage (standard two car garage 4-12 roof)? Answer: I worked for a long time for a prominent wood stove, insert, and fireplace manufacturer. Over the years, I've discussed this same issue with folks from all over the world. It's a very gray area that you're treading upon. There's a couple of ways to attack this. First, and above all, it must be safe. It must conform to safety listings. It must be approved by your local codes. It must conform to manufacturer's requirements. Your insurance company has to be okay with this. You have to try and find out who made the insert. There must be a tag, or label somewhere on the insert. Check the back. If you find it, call the manufacturer. Above all, CYA! Typically inserts are designed for actual masonry fireplaces. No combustibles involved. Just non-combustible masonry brick or block surrounding the insert like a box. That's what you need to do also (borrow a fireplace book from the library for ideas). For best performance, the chimney flue size, whether it be masonry or a metal Hi-Temp chimney, should match the insert's flue collar, and the connection between the two should be tight, and dripless (pipe/flue above going into the pipe or flue collar below). If the fireplace is outside of the garage, the chimney & fireplace should have a 2" clearance to the wall. The chimney should extend above the roof line three feet, and the termination must be two above anything within ten feet, regardless of pitch. Will this be economical? Tough question. Maybe. It might be a heckuva lot easier in several ways to sell the insert, buy a freestanding stove, put a metal chimney on the outside of the garage and run the chimney vertically along the wall terminating above the roof line. One hole through the wall for the pipe, and run the chimney. My Dad is also a carpenter (retired), and this is what we did years ago for his garage. He thought about doing the same thing, but when we weighed all of the issues, he went with a stove. It works slick, and conforms to every spec. and code. No gray areas. Dennis, cover all of your bases first (codes, insurance, etc.), then decide what to do. Good luck.