I only had mine down a foot as I was crossing buried 220 volt AC lines that
were down about 4 feet (according to power company - I didn't see any signs
of them). I also have very rocky soil with lots of limestone "shelves" that
I hit when digging my tower base. I actually poured my base on one of them
that the backhoe/jackhammer operator worked on for an hour. It was a very
big hunk of limestone.
Buried waste drain (poop chute) has to be schedule 40 minimum (depends on
local code) but French/foundation drains can use the pref'ed thin wall. It
doesn't matter if it gets compressed. You may be able to use thin wall for
waste system vents also.
I laid two 80' runs of 3" gray PVC conduit, one run of 2" and a 1" run for
about $150 in material. I guess if you had a 200+ foot run the thin stuff
would look attractive.
There are cleanout boxes you can get for drain systems that have a open
bottom for a gravel bed but they are designed to be mounted flush with the
ground. You can get them with solid or grate lids but they sure aren't
73 de Perry - K4PWO
From: Larry Loen [mailto:firstname.lastname@example.org]
Sent: Wednesday, June 27, 2012 5:31 PM
To: Perry - K4PWO
Subject: Re: [TowerTalk] Coax, conduit and toroids
I discussed this very thing with my father, who is a civil engineer.
He said that once you got far enough underground (don't know the minimum,
but I'm planning on four feet) he said that vehicles wouldn't be a big
problem -- forces are spread through the soil.
The main thing is to make sure there isn't any rock in immediate contact
with the tubing, especially above and below. A nice sand base below the
trench is vital.
Around here, the cost difference is very substantial between thick wall and
Moreover, it must be routine to make this work -- the thinner PVC is used to
conduct waste water from homes to sewers. No one wants them to break!
On Wed, Jun 27, 2012 at 10:26 AM, Perry - K4PWO <email@example.com> wrote:
> Another issue is that most "drain" tubing has a very thin wall
> compared to PVC conduit. If you have rocky soil or will have the
> "conduit" buried under a path where vehicles will travel, you will
> want heavy walled tubing (PVC EMT conduit). I have discovered that the
"gray" PVC is cheaper than "white"
> water PVC in most sizes (in my area of the US at least). The gray
> also stands up better exposed to sunlight.
> 73 de Perry - K4PWO
> -----Original Message-----
> From: firstname.lastname@example.org
> [mailto:email@example.com] On Behalf Of Missouri Guy
> Sent: Tuesday, June 26, 2012 11:15 PM
> To: firstname.lastname@example.org; TowerTalk@contesting.com
> Subject: Re: [TowerTalk] Coax, conduit and toroids
>> What should I do to help ensure that the inside of the conduit stays
>> dry? Is applying some sort of weatherproof sealing compound to each
>> end enough?
> I have a large "conduit" running 200' to one of my towers. So,
> speaking from experience, there is no easy way to keep water out
> unless you want to pressurize the conduit with say, dry nitrogen
> gas. That isn't going to happen!! :D)
> Air will get in there even if you attempt to seal it off, and then it
> will just form condensate in the cool ground.
> Mold will grow, etc etc.
> I found the best way (for me, anyway) is to install a Tee connector at
> both ends of the run. Face the Tee part downward and screen it over
> to keep out bugs, snakes, or whatever. Air will flow through your
> conduit everytime the wind blows and will keep things nice and dry.
> Here in the US, and probably in AU, there are some screened aluminum
> louvers that will work for most of the larger conduits (like, in my case,
4" PVC tubing).
> As for your other questions...there are some experts on the list who
> will address those.
> Charlie, N0TT
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