Clarify 3 foot rule when chimney does not penetrate roof (through the wall installation)

[miiii]

How tall does my chimney need to be?

The installation is through the wall, and up the side of the building. There is no eave or soffit to penetrate, the roof does not protrude, the roof is flush with the side of the building. The chimney is in the centre of the wall, so it is located at the peak of the roof. The chimney will be 2~3" away from the wall. The siding and roof are both ribbed metal over wood studs.


Since the chimney does not penetrate the roof, does the 3 foot rule not apply?

Should the height of the chimney then be 2 feet higher than the peak of the roof? (based on the 10-2 rule)

 

[DAKSY]

The TOP of the chimney pipe has to be a MINIMUM of three feet higher than the roof,
no matter where it passes thru or by that roof.
The three feet is measured on the uppermost side.
The 10/2 rule applies from that three foot location.
If everything within 10 feet is lower than the top of the chimney, all is good.
If not, then the 2 foot rule applies

 

[begreen]

click image to enlarge

 

[Drewman]

I am going to highjack this thread since my questions is exactly the same only the chimney will not be at the center roof line as shown. It will be coming up the side of the house and not the end. I will be building a chase on the side of the home.

The roof is slopped such that for every 12 inches it raises 6 inches. How high above my roof line/gutter line where the chimney passes will it need to be. I imagine the same which is 3 feet. This will be on a 2 story home and be over 15 foot tall in total as well. Outside air kit for also installed.

Please clarify.

 

[littleuing]

I am by no means an expert and only know what i was told... But if your more than 10 feet to to peak you would need to be 7 feet above the roof line... Let me explain my thoughts and wait for others to verify..

If the peak is more than 10 feet it will take you 5 feet to get nothing higher than your pipe at 10 foot away... Then 2 feet past that puts you at 7.

If your within 10 feet of the peak you need 2 feet above the peak.

 

[begreen]

This would depend on the roof pitch.

 

[littleuing]

He said for every 12 inches it goes up 6 inches so to get 10 feet away he has to go up 5 feet... Am i missing something?

 

[bholler]

He said for every 12 inches it goes up 6 inches so to get 10 feet away he has to go up 5 feet... Am i missing something?

sounds right to me

 

[DAKSY]

I am by no means an expert and only know what i was told... But if your more than 10 feet to to peak you would need to be 7 feet above the roof line... Let me explain my thoughts and wait for others to verify..

If the peak is more than 10 feet it will take you 5 feet to get nothing higher than your pipe at 10 foot away... Then 2 feet past that puts you at 7.

If your within 10 feet of the peak you need 2 feet above the peak.

Take the pitch of the roof (rise over run). Multiply the TOP number (rise) times 10. Add 24" to that number & that will be the height your chimney will extend out of the roof on the higher side. If you are less than 10 feet to the peak, you multiply the TOP number (rise) by THAT distance instead of 10. Then you add 24" to the product.

 

[begreen]

He said for every 12 inches it goes up 6 inches so to get 10 feet away he has to go up 5 feet... Am i missing something?

Yes, for 6/12 pitch.

 

[DAKSY]

Yes, for 6/12 pitch.

NO. For a 6/12 pitch 6 x 10 = 60 PLUS 24" = 84" He needs to go up 7 feet, unless he is closer than 10 feet to the ridge.

 

[begreen]

Right I thought that was what he originally said. 7 ft.

 

[Drewman]

May calculation was for 7 feet as well...that just seems high. Can't argue with science...