Forge Chimney Advice

[Augus7us]

I've decided to get back to work on my shop and hopefully make a knife before I forget how. One thing keeps biting me in the ass though and that is the chimney for my coal forge.

I've called about every roofer and chimney guy in the phone book and that is a no go. So it looks like I'll have to do it.

Here are some questions I have for those that have done this:

I have no idea what code is for a hood going over a forge or if any even exists. Is there code for this?

Did you run double or triple wall pipe? Triple wall seems to be out of style as its hard to find and very expensive.

I know going straight up is best but what is the downside of going out the wall and up from there?

I heard you don't need double(triple) wall pipe all the way down, just where it runs through the ceiling and up from there. Down from the ceiling can be single wall. This appears to be how my utilities are in my basement. Can I get away doing this with the forge hood? I'd rather not spend a grand on pipe!

Thanks guys!

 

[Fred.Rowe]

Triple wall needed at the ceiling or roof line and anywhere the pipe is out side a heated area. I've run a side draft coke forge that I enjoyed. The reason for a straight pipe is how they draw. When you first start your forge you will want the hood and chimney to draw when the forge is first lit, otherwise your shop will fill with smoke. You can make your own insulated pipe using one pipe inside another with kaowool separating the two. Fred

 

[Hubert S.]

I don't know about forges, but I built a pizza oven and back then I found the local building codes for chimneys. I could only do a 45 degree bend for an offset, not 90. IIRC, ninety degree bends were only allowed for some gas burning appliances. I used double wall insulated stainless steel pipe and premade flanges for the roofs (the chimney goes through both the porch roof and the roof overhang of the main roof above). It's been a few years, but I think the product was from duravent or something similar. It was easy to work with and passed inspection. It was also very expensive...