Hello Blacksmiths:

I am setting my forge up behind my house under a spring porch. The patio below the porch allows room beyond the extend of porch and roof line over-hang for the forge and hood. If I take the pipe stack up twenty feet, I will clear the roof of house by six feet. Now for my question, since I am not going through a roof and the pipe will be 8-10" from the side of house. Do I need to only use stove pipe (8") for the first four feet above the hood and then use the less expensive *"duct" pipe for the remainder?
Or, Should I use the heavier stove pipe all the distance to the top. Or can I use the lass expensive duct pipe for the whole extent? I plan to put a top cap with screen to prevent water coming down the pipe.

Being as our area is very dry, my spouse worries about my forge starting a fire (on the house and/or in the woods) from sparks flying. It seems to me a twenty foot stack would cool off any sparks and provide a good draft?

I plan the use 1"x 1/8" mild steel as straps to hold the stack secure and to attach the stack to side of porch and maintain distance from the house. Then, I will paint the pipe stack forest green to hide it in the trees behind my house.

What is the best material and how high above the forge hood does it need to go?

Thanks for your thoughts!
Houston the Armouror