Select your garage gas heater by fuel type and BTU output appropriate for the environment. Our ceiling-mounted vented gas heater has an electric fan for circulation and a flue to vent fumes through the roof. A one-person project using block and tackle rigging to hoist the heater to a ceiling joist, it requires several trips to work from the roof.
Lag-screw two-by-sixes across ceiling joists to corner-mount the vented gas heater. These gas heaters are designed to hang from the ceiling joists, but aiming flow from the circulating fan diagonally across the garage will improve airflow in this situation.
Hook the upper end of a block and tackle to the beams and the lower end to cargo straps wrapped securely around the gas heater. Use the pulley to hoist the gas heater up to the joists and into position.
Position and temporarily clamp the heavy gas heater to the joists along its mounting flanges. Bore equally spaced clearance holes for carriage bolts in the ready-made cutouts along the mounting flanges.
Insert a carriage bolt into each clearance hole and tap the head with a hammer to seat its collar in the wood. Twist on nuts and then finger-tighten and then snug them with a socket wrench. Remove the clamps.
Attach the T-shaped portion of the flue to the back of the gas heater. Use a plumb bob to determine the exact vertical position above the center of this flue pipe on the underside of the roof. Mark it.
Bore through the mark, inserting a wire to locate the hole on top of the roof. Outline the diameter of the flue, centered on the hole. On the outline, bore a pilot hole for a jigsaw and cut the opening.
Center and mark the oval opening of the funnel-shaped flashing over the cutout. Cut away upper shingles along the mark. Apply sealant to the lower shingles and slide the flashing base under the upper shingles. Secure with roofing nails.
Insert the vent pipe through roof and flashing. Connect the lower end to the T-shaped flue, securing it with snap-in-place couplings. Add the weather ring and vent cap to the upper end of the pipe. Add sealant to nail heads.
Remove the side panel from the gas heater housing to access the electrical components. Match wires and secure with wire nuts, following gas heater manufacturer's directions to make electrical connections for components such as the air circulation fan.
Apply thread sealant to the gas pipe sections and screw them together. Snug the fittings with adjustable wrenches. Connect the flexible gas line and tighten the nut. The main gas line and shut off valve were installed before this project.