Garage Heater Venting

[Moonshine]

OK, last garage question. My projecy is almost done. I was able to get my hands on a 75K btu Mr Heater garage heater at next to nothing. I know thats not the modine, but the price was right. I need to vent the heater and am unsure on the process. I found out it needs to be vented through ceiling due to its locaion, not the sidewall. My question is how I go through a finished ceiling, line it up with roof and make it all work. I hung the unit and can get ceiling hole cut, just wondering how I line that up with roof and cut. Its about three feet from ceiling to roof. Do I cut roof hole with a jigsaw? Any help is much appreciated.

[Archerysniper]

Use a plum-bob to line up the the hole to the vent,make sure you use the proper vent boot and have the right clearance from combustibles for the class vent pipe you are using. I use a sawzall to cut the roof penetrations.

[Surface Tension]

Go to Mr Heaters site download the manual and pick up a vent kit or buy the individual parts separately.

For the roof penetration you'll use 4" galvanized roof flashing.

Use the plumbbob like Archerysniper said. Situation your mark so it is centered in the hole and drill through the roof with a 1" spade bit. Since this will need clearance the hole will be bigger then the vent pipe. That'll mean lifting shingles before you cut the hole.

You'll need a flat bar to slide under the shingles and carefully lift the nails out. A reciprocating saw works best but your jig saw will be fine. Set the pipe and flashing. You can move the flashing around till your pipe is plumb but be sure you still have the clearance between the pipe and roof deck. Now tie the flashing into the shingles. In a netshell, the shingles will look like an upside down U when your done. The bottom half of the flashing will be over the shingles and the top half will be under the shingles. Where you removed nails use roofing cement when replacing the nails.