chimney question

[ssupercoolss]

i am back in action and will be installing a new yorker wood boiler, not the harman boiler that was likely to be delivered some time in 2010. anyways....i managed to poke through my 24" stone foundation, one big hard stone left and my hole will be complete. now, heres the deal. the chimney exits the house, below grade. i planned on basically pouring a big concrete box (think window well) around the pipe, big enough for access to the cleanout. what i didnt realize, is just how far below grade this whole deal actually is. this is gonna be a pretty deep hole, and awkward to access the cleanout. so the million dollar question is, can i put my cleanout tee on the inside of the house, with just a 90 degree elbow on the outside? then my second question is, if i do that, how do i support 24' of chimney that way?

i am using class "A" chimney....kinda forgot to mention that.

 

[stee6043]

I have a similar situation as you. Here's something to consider - I'm not sure you can get 90's in class A chimney? I've only seen 15's and 45's. At any rate, you may want to consider simply using two T's. Use a T when you come through the wall and use a standard wall support. Throw a few feet of straight on it and throw another T in where you can more easily access it. The trick here is that you really will want to still get a hold of the plug on the bottom T to let all the junk out. Even if you aren't brushing through the bottom T you will need to empty it.

I plan to support my 21' of Class A chimney with a couple of 4x4's cemented in. I need to come out from my basement wall about 11" on the outside and go straight up, with a chase. So I can't really tie into my house at all at the bottom. Nothing a little lumber can't take care of...