Fireplaces, Heating Stoves, Flues and Chimneys - How to properly lay a block chimney

Hey, I 'm installing a wood boiler in my garage and need to build a single flue block chimney up the back side of my garage, Appx 16'-20' from ground. I know i need to build a 40" X 40" X 12" thick footer 4' below grade . Then what? Can anyone give me the process from the footer up? Also does the chimney need to run up the outside wall, Thus removing the vinyl siding? does it need to be straped to the wall? Any input would be greatly appreciated.

The bottom of the footing should be below the frost level.

The siding should be removed to permit attachment of the chimney to the garage.

Flash the roof to keep the water out.

Make the chimney high enough to draw.

Use a chimney cap.

Dick

Thanks for the info, Kinda looking for a step by step from the footing up, like should i use regular block up untill the outside cleanout? What kind of mortar/ rebar? Spacing or any insulation on flue? Basically i'm looking for a step by step procedure. Thanks.....

You can lay regular block up to the clean out. You'll need to use cat block or otherwise fill the block to make a floor for the clean out opening. I assume you plan to use the 16" square flue block [I think the new ones are 17"sq]. You'll need the 7" flue liner. Get the thimble in the length/size you need and the flue liner and 2 pc chimney block that is cut out for it.

I used the type n mortar on the 2 chimneys I built but I'm not a mason and don't know if that's the correct/best mortar to use. I have seen a few chimneys that were built standing off of the wall but I think they look tacky and don't believe they would be as stable as one built against the wall using brick ties.

You might also want to buy a chimney brush [sized for the flue you use] to keep it clean = better draw and less chance of a chimney fire.

Thanks for the input!!