To connect the exhaust pipe:

1. Fasten the top mounting coupling for the vent pipe with screws to the top (or the side) of the composter.
2. Use the flange provided or secure the proper flange for the diameter of the exhaust pipe selected.
3. If there is no flange available, cut a ¾ in. (67 mm) length of the vent pipe and cement it into a coupling. This will leave a short one-in. stub beyond the edge of the coupling.
4. Find the best possible place to make the hole on the top of the composter, if there is none provided, taking into consideration that the pipe should be as straight as possible. Note: The fewer the elbows the better the ventilation.
5. Using the outside diameter of the vent pipe as a guide, draw a circle on the top of the composter where you want the vent pipe to be located.
6. Carefully cut a hole in the composter (unless one exists).
7. Place the stub of the vent pipe in the hole cut into the composter and caulk it thoroughly with silicone to prevent odors from escaping when the system is in use.
8. Insert a union or a no-hub flexible coupling in the line to allow you to remove the composter for service without destroying the exhaust pipe.
9. Install the fan (if required).
10. Cut a hole in the roof straight above the exhaust vent pipe. Use a plumb bob to determine exactly where to cut.
11. Push the ventilation pipe through the hole in the roof and down into a roof boot on the roof. (The roof boot must match your roof pitch and the pipe diameter.)
12. Fasten the rubber flashing gasket both to the ventilation pipe and to the roof with the silicone. This prevents rainwater from seeping into the building.
13. Make sure the exhaust vent pipe is as straight as possible and that all joints are sealed with silicone caulk. In colder climates, insulate the vent pipe to prevent condensation and to improve the draft.
14. If you suspect that wind might cause strain on the pipe where it meets the roof, install a wood stove pipe brace on the roof to prevent damage.
15. Mount a rain cap (or a 90-degree tee) on the exhaust pipe and fasten it with silicone.
16. Cover the outside of the cap or tee coupling with a loose bag of rust-proof fly screen. Fasten it around the vertical pipe with corrosion-resistant fasteners, such as stainless-steel wire or hose clamps.

The UNISEAL™ rubber grommet is a simple, one-piece, and inexpensive way to connect a pipe to a tank. It can be installed in minutes. Use it for pipe diameters from ⅜ in. to 6 in.