Mike Jay wrote:Will you have a living roof?
Mike Jay wrote:Just as a side note, have you heard about reciprocal frame roofs? If I was doing a round building I'd be incorporating that style of roof. No center support needed and they look cool to me.
Mike Jay wrote:282,000 lbs is a lot of weight and I'm a bit surprised that pipe could hold it up.
William Bronson wrote: Your chimney is vastly oversized.
Rocket chimneys are usually sized to match the system.
8" is large for a batch box.
13" is humongous!
I would use this pipe as the outside form for a concrete cylinder.The inside form would be 8" diameter duct, the mix would be perlite and RapidCast Cement.
William Bronson wrote:
Consider making your central rocket mass heater your primary heater,since it's likely to be at least an 8"system.
Then your secondary rocket can be placed on an outside wall,or better still a porch. This will let you use it during hot weather without radiating heat into your living space
Glenn Herbert wrote:The center column will actually support 1/3 of the total load. Divide the roof into triangles, and the load is larger toward the outer edge of each triangle. This calculator will give an idea: Beam Bending Calculator
Select the beam with the triangular "shed roof" load, and look at the "shear" chart. Shear is the vertical stress in the beam, and it will equal the support load at each end. -20 at one end vs. 40 at the other end (take the absolute value for our purposes) gives twice the load for the wall end of each beam as at the column end.
Glenn Herbert wrote:Aside from draft considerations for the RMH, building code forbids a chimney from carrying external structural load unless designed for it (I expect it would take a professional engineer's stamp to satisfy any building inspector if you have to deal with that.) The 2 1/2" of insulation space around an 8" chimney would be adequate FOR RMH USE, I'm sure, but you might not get any authority to put their liability on the line for it.