Very tall free-standing pole (for stove-pipe support)

[metalmaster]

Re: Very tall free-standing pole (for stove-pipe support)

the diameter of the material has more bearing on strength than wall thickness.
as long as you don't overload it with extra weight at the top, and make sure to properly
attach it at the base it will be fine.

[kebwi]

Re: Very tall free-standing pole (for stove-pipe support)

So, a few posts up I showed a photo of a pole I bought and gave some basic specs on it and since I didn't receive any glaring objections, so I assumed it was a good pole for this project. I've been building my design toward using this pole for a while now, but some subsequent research has me second-guessing my design. For example, I keep reading that for a given thickness, aluminum is 1/3rd as strong as steel, so a 1/8" aluminum pipe is worse than a 1/16th steel pipe (it's no better than 1/24th" steel in fact!!!). Intuitively, this seems ridiculous to me. A 14', 1/24" steel pipe would flop over like a noodle but this 14', 1/8" aluminum pipe is confidently sturdy -- it was obviously intended to be used as a vertical pole (it's a lamp post of some sort), whereas you would never see a 1/16" (much less 1/24") steel pole for such a purpose.

So I'm very confused. Is this a strong pole or not. The fact of its existence and original purpose would suggest yes, but the math makes no sense.

Furthermore, some looking online suggests that schedule 40 aluminum pipe at the diameter of this pole would be .2" thick at the top and .226" thick at the bottom. Like I said, it's .125" thick.

Is this thing a dud? Do I need to start over with a different pole? I don't understand how it can be so weak, yet so seemingly strong at the same time.

[kebwi]

Re: Very tall free-standing pole (for stove-pipe support)

There are a bunch a scrap yards around here, but I think they are mainly for recycling, so they want to take people's stuff but never advertise much interest in selling back. I'll call around and see what's up.

Cheers!

[countryboy]

Re: Very tall free-standing pole (for stove-pipe support)

Do you have a scrap metal salvage yard around?

We have a metal recycling place nearby that has a yard for the 'nice' culls out of the scrap. I go and browse looking for what I want then pay deep discount over new... They'll have what you are looking for and likely will cut to length and sell by the pound. Best route, hands down.

[kebwi]

Re: Very tall free-standing pole (for stove-pipe support)

Did anyone have any thoughts on the last post w.r.t. a PVC, rebar, and concrete column as a foot to slide a pole over?...as opposed to a piece of steel pipe? I also posted a photo of the aluminum pole I got two posts up the thread. It's 1/8" thick.

Cheers!

[kebwi]

Re: Very tall free-standing pole (for stove-pipe support)

To make a pipe foot to slide a pipe pole over, one would conventionally use, say, a heavy steel pipe of OD just slightly less than the ID of the pole. Such a pipe is probably really expensive (I can't find any second-hand for example).

Could I achieve a similar effect by using a piece of PVC, dropping several pieces of rebar in it (maybe even lengths of smaller easier-to-source pipe), and filling the thing with concrete? This would extend into the concrete anchor at ground level down about three feet, but would then project upward from the ground a few feet.

Would that work?

[kebwi]

Re: Very tall free-standing pole (for stove-pipe support)

So today I bought this off Craigslist. It's an old lamp post that the previous guy got from some Seattle surplus source. He was using it as a CB antenna tower (it went several sections above this piece on various extensions for his purpose).

It's aluminum so it weighs practically nothing. It's 14'2" including the base, 1/8" thick, 2-7/8" OD at top, 4" OD at bottom, 12-1/2" OD at base. He mounted it by sliding it over a 3" pipe in the ground, so I think I'll do something similar, embed some sort of pipe in the concrete sticking up a few feet and slide this over the top...so I guess I need another piece of pipe. Ergh.

I'm not quite sure whether I should "fix" it to the pipe-footing. I can't imagine how I would do that without drilling holes through it, which would be a shame. The mounting brackets at the bottom of the base are completely broken off so the base can't be mounted in a conventional manner (bolts).

And then I need to figure out how to attach the boom. Again, it would be nice to not drill through the pole. A clamp around the outside seems obvious except that the pole is not cylindrical, so any clamp could loosen if it works its way up the pole. Hmmm...

Also, the top is open, so I need a cap of some sort, probably not hard to find (fingers crossed).

I also still haven't ruled out adding a second pole just for the sake of redundancy...but they would never match, so, I dunno.

Cheers!

[WJW]

Re: Very tall free-standing pole (for stove-pipe support)

Gulf is a genius!

Many, many jurisdictions around the U.S. have laws intended to promote alternative energy solutions like windmills. A place as militantly liberal/green as Seattle is bound to have such laws. (I'm can call your town "militantly liberal" because I live in Southern California and we are every bit as looney in that department as you guys. )

So you put a windmill at the top of a 20 foot metal pole next to your oven and call it green energy. A few weeks later you put up your chimney and tie it to the pole.

The reason I think it's important to have some legal cover for the pole is that your crazy neighbor is probably going to find a reason to complain about the tall pole next door. Interferes with butterfly migrations...or some other highly legitimate concern.

All kidding aside...you really should look into what the local codes will allow with respect to a structure like your twenty foot pole. Are you allowed to put up a twenty foot flag pole in your yard? A twenty foot tall ham radio antennae?


I'm no engineer, but I do think you'll need a stout metal pole to do the job. Maybe four or five inch diameter with relatively thick walls, sunk three or so feet down. I have no idea what the lateral loads would be with sixty knot gusts hitting that chimney, but they must be significant. If I were you I'd make some determinations as to what the likely peak winds are going to be during any given twenty year period...do the calcs on the lateral loads imparted...and then decide what you need...and build in a safety margin. I think you'll find you need metal and that it needs to be stout.

I also think you are going to find that there are building codes which come into play...and that your neghbor is going to force you to get acquainted with them.

Bill

P.S.: I know you're tired of the "Kill the neighbor" jokes...but I'm just saying.

[Gulf]

Re: Very tall free-standing pole (for stove-pipe support)

kebwi,
If you are thinking about putting mutiple poles in the breeze, How about the structure pulling double duty.

You probably wouldn't want it to pump water, but a little help on the electric bill would be nice. Even if it isn't funtional a rustic wind mill might look good, hide, and brace your chimney .

[kebwi]

Re: Very tall free-standing pole (for stove-pipe support)

Sorry, did not mean to belittle your crazy neighbor situation. I will never bring it up again.

It's not you, don't worry about it.

...the support needs to be pretty strong. A second pipe next to it that the chimney is attached to will have to be very beefy to withstand the constant movement of the wind. Sure may days it will not be bad, but over the days and months that thing will move a lot. Guy wires are used in industry all the time, because they allow only minimal flexing. In my opinion, with a chimney this tall, guy wires are probably the best option.

If you cannot do the guy wire route you are probably going to need something on the order of a telephone pole. And those are pretty ugly.

Point taken, I'll keep it in mind.

[kebwi]

Re: Very tall free-standing pole (for stove-pipe support)

For a second there I thought you were talking about your wife giving you grief about the wires in the yard...Thinking sh** this guy will be living in the dog house if she read that post...

Okay, THAT was hilarious.

Thinking of your design... you could also run two shorter poles then brace a triangle between the two poles and the chimney pipe and let 4 or 5 feet free stand above your support.

Yes, I am liking the idea of two poles the more I think about it. It would make maintenance easier since one pole could support the stove pipe while work is done on the other.

Also thinking if your a flag kind of family you could also use flag poles so you could brace your chimney and also make it have a decorative purpose. Love the sound of a flag on a breezy day.

Plus, I could fly a flag at the same time that I use the oven. Oh wait.

[Jaronimo]

Re: Very tall free-standing pole (for stove-pipe support)

Sorry, did not mean to belittle your crazy neighbor situation. I will never bring it up again.

My comment about securing the chimney, which I realize you understand needs to happen, was more along the lines of the support needs to be pretty strong. A second pipe next to it that the chimney is attached to will have to be very beefy to withstand the constant movement of the wind. Sure may days it will not be bad, but over the days and months that thing will move a lot. Guy wires are used in industry all the time, because they allow only minimal flexing. In my opinion, with a chimney this tall, guy wires are probably the best option.

If you cannot do the guy wire route you are probably going to need something on the order of a telephone pole. And those are pretty ugly.

[Faith In Virginia]

Re: Very tall free-standing pole (for stove-pipe support)

If you want to deal with this constantly harrassing bullying woman, then come to my house and do it.

For a second there I thought you were talking about your wife giving you grief about the wires in the yard...Thinking sh** this guy will be living in the dog house if she read that post...

Then I remembered your the one with the crazy neighbor.

Thinking of your design... you could also run two shorter poles then brace a triangle between the two poles and the chimney pipe and let 4 or 5 feet free stand above your support.

Also thinking if your a flag kind of family you could also use flag poles so you could brace your chimney and also make it have a decorative purpose. Love the sound of a flag on a breezy day.

[kebwi]

Re: Very tall free-standing pole (for stove-pipe support)

This is a lot of work to try to keep the smoke from touching the neighbors house?

I'm getting tired of responses like this. They dismiss the severity of the situation. If you want to deal with this constantly harrassing bullying woman, then come to my house and do it. Otherwise it's me all alone out there for two hours.

20 feet of chimney is pretty tall and will have a huge amount of surface area. That will catch a lot of wind. It will need to be secured or it will bend and break on gusty days.

Umm, well sure. I don't think that any point in this thread there has been any discussion of whether support is required, but rather the method. I never had any illusions that a stall stove-pipe would simply balance on its base for ever.

I believe this all stems from the black spots on the neigbors siding? I get those on my house near any spots that have mulch. I even get some on the cars. They are spores, not smoke damage.

I completely agree...I guess...I dunno. She would immediately claim she finds more such spots the day after I use the oven. Obviously, that's because she looks for them, but logical statements like that are pretty irrelevant to the circumstances. I'm the only one dealing with her and I'm out of ideas.

[Jaronimo]

Re: Very tall free-standing pole (for stove-pipe support)

This is a lot of work to try to keep the smoke from touching the neighbors house?

When I light my oven, the smoke does not always go up, it goes sideways and sometimes downward depending on the wind and nearby obstructions.

20 feet of chimney is pretty tall and will have a huge amount of surface area. That will catch a lot of wind. It will need to be secured or it will bend and break on gusty days.

Three guy wires would probably be the least visually obtrusive way to do that. If you are worried about kids tripping over the wire/ground connection point, you could anchor three 8 foot or 10 foot poles or railroad ties, halfway in the ground and then attach the guy wires at the tops of those poles.

I believe this all stems from the black spots on the neigbors siding? I get those on my house near any spots that have mulch. I even get some on the cars. They are spores, not smoke damage.