Fire proofing smoke stack
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How would some of you go about fire proofing the 2x4s near the smoke stack? Stack diameter is 20" with about 3" between the 2x4s and stack. I have 8 oc trusses/just over 3 ft between truss and stack.
My plan is to make a box out of stainless that will go around the stack and will get anchored to the 2x4s and will fit some blanket inside between the stack and the box.
Yep, I would (and did in our sugarhouse) make a double wall pipe. Wrap stack in 1" ceramic blanket with a wrap made of stainless to go around and hold in place. Being that close 3" might want to put a layer of sheetrock on trusses to give more protection before running pipe up thru.
54 Acres bought in Sept 2010, hope for a lot of fun
Kabota 3400 w/ bucket
couple Husky chainsaws and a couple of Stihl
Big dream
2011 = 106 on gravity tubing, 100 bucket
2012 =700 vaccuum 100 gravity 80 bucket's
30" x 12' Vortex with Leader Revolution Max Raised pans
2013 = 1200 vac, 200 gravity, 5 buckets, buying from 300 buckets, 500 vac
Springtech RO 600 Deluxe
2015= 1800 all vac @ home, buying sap from 1200.
2017= 2200 all on vac. no longer buying sap
A length of 6"diameter duct pipe installed around the 2x4 will work nicely. The basic rule of thumb I've heard is that every layer you put between the hot pipe and flammable materials cuts the temperature in half. My chimney has two layers of bigger duct pipe around it with 1" of air space between it. These shields run right up through the roof and into the flashing cone, which is vented below the storm collar. It keeps the weather out, and the outside layer never goes above about 80 degrees. The adjacent timbers are wrapped with a loose fitting section of duct pipe and they don't even get warm.
I did that too on my latest improvement about 3-4 years ago. Before that I made my own triple wall pipe, but my trusses were 9" away. When I built the sugarhouse I set that one truss at 32" O.C. for a 30" space. the 12" stack goes up dead center. I have a 1.5" ceramic insulation with the SS stack inside and a second SS outside, I then cut 1.5" deep slits at the bottom of the outer layer and bent them inward to cover the bottom edge of the insulation.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.
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So here is my sleeve. I will take off the roof jack and slide it down so the stack comes through the center. There will be an inch gap between the purlins and the sleeve(let's call it) and will have a 1.5 inch gap between the stack and the sleeve. I will also install blanket between the sleeve and stack. What do you all think?
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Here it is installed. About an inch gap between purlins and sleeve, with about a 1.5inch between stack and sleeve and blanket shoved inside firmly. Will it work?
Well let's hope so. There's nothing more distracting than trying to put out a fire while trying to draw off.
@Michael Greer: "The basic rule of thumb I've heard is that every layer you put between the hot pipe and flammable materials cuts the temperature in half...."
If you wrap that hot pipe with a layer of metal, the temperature will NOT be cut in half. I think what you heard was "every inch of layered AIR SPACE" cuts the temperature in half.
Double wall chimney pipe made by Simpson (DuraVent) calls for a 8" air space between the pipe and ceiling combustibles (purlins, sheetrock, trusses, rafters, spider webs, grandma's portrait, etc). Any less, and you're playing with fire. Also, NO INSULATION CAN CONTACT THE PIPE. It's proper function relies on air freely moving over its' surface.
Last edited by Daveg; 03-25-2018 at 11:23 AM.
Daveg: aren't some of the insulated stove pipe out there have a layer of ceramic blanket between the inner and outer wall of the stack? I've had my fire box insulated with the same blanket as I have in my sleeve and I've been able to hold my hand on the firebox wall for a decent amount of time before it gets to warm for my hand. Not trying to be difficult on the subject, the last thing I want to do is burn down my sugar shack.
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