Replies

1. 
   seeyou | Dec 17, 2003 10:51pm | #1

   The easiest solution would be to splash some gasoline around the shop and then light it. That way, you can burn the shop down without having to climb up on the roof.

   Seriously, why can't you replace 10' of chimney? If it's just single wall pipe, it shouldn't be on the exterior anyway. You need a listed triplewall or insulated chimney. The stuff is not that expensive and it's pretty easy to install.

2. 
   Sphere | Dec 18, 2003 12:14am | #2

   CAN"T...a four letter word not in MY vocabulary. Call a sweep.

3. 
   Piffin | Dec 18, 2003 04:02am | #3

   the way to make it heat proof is to refrain from lighting any fires in it.

   The way to make it heat resistant is to use UL approved class A metal chimney, either treiple wall or solid mineral fibre pack.

   Seriously, if you have a few small holes, the entire body of this pipe has deteriorated to the point of collapse. You are in danger of not only losing your shop, but somebodies life also - yours, a neighbor's, a fireman's....

   This is nothing to triffle with.

   .

   Excellence is its own reward!

1. 
   jackplane | Dec 18, 2003 06:24pm | #4

   I'll look into triple wall and mineral pack.The real problem is water damage.The flue is well-braced and not in danger of collapse.

     Responses thus far suggest replacing the entire piece,which I may do,but I was looking for a product like an asphalt or rubber based sheet metal to adhere to the existing flue.Maybe this not an option?   

1. 
   rjw | Dec 18, 2003 06:32pm | #5

   MAke sure you've paid you insurance prenium AND they know you have a substandard installation and agree to cover you anyway.

   _______________________

   Tool Donations Sought

   I'm matching tool donors to a church mission to Haiti - we're shipping a bus converted to a medical facility in January (we hope) and can fill it with clothes, tools and all sorts of stuff needed in that poorest of all countries. A few hand tools or power tools can provide a livelihood for an otherwise destitute family. Please email me if you have tools to donate.

   Thanks to Jeff and David and Jim for their offers!

1. 
   jackplane | Dec 18, 2003 06:50pm | #6

    I didn't think I'd get ripped to shreads on this issue.But obviously fire safety is nuthin to play around with. Thanks to all.

1. 
   Sphere | Dec 18, 2003 08:18pm | #7

   thats what we are here for dont take it personally..

2. 
   MojoMan | Dec 18, 2003 09:15pm | #8

   Wasn't that fun? Now, try jacking up your house!

   Al Mollitor, Sharon MA

3. 
   jackplane | Dec 18, 2003 09:58pm | #9

   Hey Mojoman,

    Were you th' one with house excavated,and standing on 2x4s? Wild stuff.

4. 
   MojoMan | Dec 19, 2003 12:58am | #10

   Not me!! But, that is exactly the thread I was thinking of and the firmness with which that guy was informed that his approach might be risky.

   Al Mollitor, Sharon MA

2. 
   Piffin | Dec 19, 2003 03:08am | #11

   Nobody intended to rip you to shreds, but the integrity of the advice found here at FINE homebuilding's forum is sacrosanct.

   If you want to see ripped to shreds, stop in to the Tavern for a swill and a political comment or two.

   ;)

   but now that you are properly aware of the danger, I'll add a bit here.

   you mentioned 600°F or so. Wood stove chimneys are rated for 2200° - 2800°. This is for when chimney fires spring up. A flue rated for 600° would melt down.

   The reason I speculated that the flue might be indanger of colapse is that when metal gets pitted and springs holes in it such as you describe, is is generally suffering from corrosion and the holes you see are only the symptom of a greater problem - weakening of the whole piece, to the point that it could fall over in a stiff wind.

   But let me suppose that your shop is built like mine is, with block walls, and a metal roof, and that you never have any chipsd and dust to catch on fire in it or cause a spontaneous explosion when you open the stove door to feed it. And let me suppose that you clean the flue regularly and it never builds up any creosote tars to burn. And that this flue is still in prime condition as an 18 Ga steel pipe.

   In such an extreme case as that, if that pipe had a hole or two in it from neighborhood kids shooting a .22 for plinking practice, then ther might be a caulk that would do the job. It might have a name like GE2000 Silicone. And it might last for a few months to keep water out..

   Excellence is its own reward!

1. 
   HammerHarry | Dec 19, 2003 05:22am | #12

   Piffin, your use of words is an inspiration to us all.

1. 
   Piffin | Dec 19, 2003 08:26am | #13

   me???

   I didn't say nuthin'

   Who said that?.

   Excellence is its own reward!

4. 
   OneofmanyBobs | Dec 19, 2003 02:46pm | #14

   While you're looking at the high-temp furnace cement (comes in a tube like caulk) at your local farm store, look at the triple-wall stainless flue sections that they sell.  Enough sections to make up 10 feet should run under $200.  A number of advantages over single-wall flue.  It's legal, which single-wall metal is not.  Your shop is less likely to burn down.  The inner wall of the pipe stays much hotter and builds less creosote.  Draws much better because the gasses stay hot all the way to the top.  There is a high-temperature silicone RTV made for engine gaskets.  This is only good to about 600 degrees.  Flue gasses are hotter than that, but the pipe itself should not be quite that hot.  I wouldn't use it on the flue.  Furnace cement is not flexible, but designed for around 2000 degree temperatures.  It will hold while you plan for replacement of the flue.  Use a UL listed spark arrestor on top.  It will reduce the chances of setting your shop or surrounding area on fire.  You'll also need a roof thimble and probably a ceiling thimble.  They sell kits that have the whole deal for maybe $300.  Cheap insurance and your stove will work better.

1. 
   Piffin | Dec 19, 2003 03:08pm | #15

   all good advice except that the kits I see are closer to $500.

   And triple wall pipe is a cold pipe inner. It is the solid mineral pack that is a hot pipe to help reduce creosote build up.

   Reason is that triplewall is designed to maintain air flow between walls. There are two chambers, As the inner chamber next to the inside of the pipe warms up, the air in it begins rising, That creates a vacumn at the bottom which draws cold air in from outside so the outer chamber constantly has a flow of cold outside air to keep the framing safe.

   Consequetly, triple walls suffer more creosote buildup than solid packs which maintain a higher temp, though still much better than the single wall he has now.

   Another advantage of both is the stainless steel liner that does not rust.

   I have seen failures with both of these kinds though. When there is a chimney fire, the air ruches up through the superheated pipe so fast - like a blowtorch - that the soft metal can get sucked into the ceneter and the inner lining is then collapsed in, reducing or eliminating draft. People should always have a chimney inspected thoroughly ater a chimney fire, but sometimes such a fire happens with no-one aware of it. Any reduction in draft should be cause for concern and inspection..

   Excellence is its own reward!

1. 
   OneofmanyBobs | Dec 19, 2003 03:42pm | #16

   I put in a new flue a couple years back.  The kit with thimble and cap was only $300 and the pipe another $200, but I recall that the prices varied quite a bit depending on manufacturer and type.   Mine was through-the-wall rather than roof, which I figured was safer since only 2 feet of pipe are actually inside the house if there ever was a chimney fire.  Mine is triple-wall, but the inner two pipes have the space packed with insulation.  Air only circulates in the outer pipe.   There are several different varieties of pipe, even from the same manufacturer.  I think I used Dura-somethingorother.  Can't remember exactly anymore.   Did a lot of shopping and you can easily spend double depending on the flavor you pick.  Also, I think I got mine towards the end of the heating season and it was all on sale.

1. 
   jackplane | Dec 19, 2003 04:32pm | #17

   Bob,

    I've used hi-temp furnace cement on the woodstove itself;it becomes brittle and falls off.That's why I doubt it'll work outside with even more expansion and contraction.ATV silicone?, maybe, I'll look into other silicones as a temporary fix.

     If I could get stainless sections at the prices you describe,I'd be thrilled 'cause I've seen that stuff at much higher prices.

1. 
   OneofmanyBobs | Dec 19, 2003 05:26pm | #18

   Don't know if they have any where you're located, but I bought mine at a farm supply store.  They had the best prices anywhere around.  A few of the home centers now have similar stuff, but less selection and it doesn't look to be as good a grade product.  The woodstove stores have a much higher markup.

2. 
   seeyou | Dec 19, 2003 10:09pm | #19

   There's also a big difference in price between 6" and 8". I haven't noticed the flue dia. given in previous posts.

3. 
   Sphere | Dec 19, 2003 10:36pm | #20

   post 1 ..6 in..I have never seen insulated in 6"..I am sure it exists somewhere..

4. 
   Piffin | Dec 20, 2003 04:44am | #22

   6,7,8,9,11

   8" is most common but others not hard to get.

   Excellence is its own reward!

2. 
   Piffin | Dec 20, 2003 04:40am | #21

   Yours is the new fangled hybrid. It came about because the old solid packs like the metalasbestos brand used actuall asbestos mineral fibre. That stuff went bye bye, even though it was very good. Most of the asbestos I have sucked in has probably been from failed potions of that pipe.

   So when they repalced it, some of the fill materials were not as good as the asbestos, and with too many DIYs installing it, too many pipes went in houses without proper clearance. The extra outer layer was added for efficientcy and safety concerns.

   I thought you were including a basic length of pipe in the "kit" for the pricing. Sounds like you paid similar to what it is here.

   Excellence is its own reward!

1. 
   OneofmanyBobs | Dec 20, 2003 05:34am | #23

   I think my kit came with one section of flue.  3 feet maybe.  Had to buy some extra ones of course.  It looked like a good value to me.  Well made.  Being off-season, I think it was around 1/3 discount.  The wall thimble was a bit of a problem.  Had brick veneer, airspace, stud wall, sheetrock, airspace, and tile-covered durock on steel furring.  Don't remember how thick exactly, but a lot more than the thimble was designed for.  Luckily they sold extension pieces so it all went together eventually.  Including all the required air spaces, it was a big hole.  More than a stud bay I think.  Had to cut one stud and head it off.  It is definitely a fair amount of work to install these things.  I can see why some DIY jobs might not be done right.  Its very important to keep the required clearances.  The insulation looks like some sort of ceramic fiber.

   The other good thing about the through-the-wall version is that the 90 fitting on the outside has a cleanout door on the bottom.  Slide one piece of sheet metal and stuff in the brush.  Takes no time at all and no mess in the house.