It is usually easiest to install stand alone gas fireplace on an exterior wall, as the venting pipe can go straight out the wall. Also remember that the pipe will need to go between studs, so you should take that into consideration when picking an exact location.
It may be easiest to order all the parts you will need for your exhaust piping when ordering your fireplace. This will include pipe between the fireplace and the wall, a wall-pass-through, and exterior pieces for the pipe.
Fireplace companies may have pre-made platforms for you to purchase. It may be most convenient to order a platform when you order your fireplace. Be sure to consult any manufacturers instructions regarding how the platform should be installed and what it can be made from. You will also need to allow for any clearance around the fireplace that is required by the manufacturer’s instructions. This will probably include clearances from combustible surfaces in the room and positioning so that the exhaust pipe can be appropriately installed.
You will begin by attaching a straight pipe to the starting collar on top of the fireplace using stove cement. Different fireplaces require different gaskets to completely attach the pipe to the collar. Be sure to follow manufacturer’s instructions for this step. Once you are able to determine where the hole for the exhaust pipe will go, use a pencil to trace a circle around the pipe at the wall. Then move the fireplace platform and the fireplace out of the way so you can have easier access the wall when cutting the hole.
Before just cutting all the way through your wall, make sure that there are no electrical lines or pipes in the area you are cutting out. Use a drywall saw to carefully cut a square hole around the tracing you made. Remove the drywall so that you can see into the wall, making sure all utilities are clear from the area. Drill a hole from the inside through the outside wall to show you where the corners are on the outside of the wall. If your wall-pass-through is square, it’s easiest to drill a small hole at each corner. On the outside wall, use the appropriate tools based on your materials to complete the hole you started on the inside.
Place the stove back onto the platform and secure all piping between the stove and the wall-pass-through, always following manufacturer’s instructions. Use high-temperature caulk to seal the area around the pipe and the fire stop. Outside, install the exterior fire stop and drip cap using appropriate tools for your type of exterior wall.
Remember to follow manufacturer’s recommendations for maintaining space between the fireplace and the frame. This is very important!
