Oil Furnace Flue Clearance

I’ve searched the old BBS and can’t find the answer. Can you kind folks guide me to the IRC code for clearance to combustible for an oil furnace connector? (Is the proper word *connector *or flue?)

Please see the attached photo. Furnace is new. I think the pipe is single wall and it touches the floor joists above.

I think it’s table M1803.3.4 that I need to reference, which would require 9 to 18 inches but I’m not sure.

Thanks.

022806 106.jpg

022806 106.jpg

022806 106.jpg

Single wall flue 1" dbl wall 6"

Thanks Brian. But I think you reversed it accidentally. However, for my future reference, where is that stated???

Sorry T2427.7.7 according to code check for 03 irc