Not wrong :). I have a bit of experience in the matter. I have seen
structures fail from a leaky unpressurized sewer pipe that was fine when
they built it. The top 1.5 feet will provide so little lateral support that
it really not matter. If you do leave it in place keep in mind that you are
taking on greater risk. My experience as a foundation engineer says move
it.
I come across this situation all the time. Anytime someone wants to build
an addition or where there used to be a structure I tell them specifically
to move or remove any utility that is within the footprint of the
foundation. The only caveat is anything larger than 6 inches they can
abandon and fill completely with 500 psi grout. Its nearly impossible to
fill anything smaller with a sufficiently strong grout.
I can think of at least 100 different cases where a structure has sustained
significant damage from a utility that broke because of an imposed
foundation load which I have personally been involved with. If you do leave
it in place the foam could compress and break any plastic pipe. I have seen
that one too. Just ask the guy in carefree arizona who spent 500k on a
brand new house and the water line broke where they put it "through" the
foundation for his kitchen island sink. They wrapped it in foam insulation
which compressed as the foundation settled and then the pipe broke. 34k
gallons of water into the subgrade. Water is expensive in az. So was fixing
the foundation that settled 3 inches and the slab that lifted up 2 inches.
Over 100k all said and done. That is an extreme case.
I have tons of horror stories. I only hear about the failures so there may
be many successful installations with pipes through the foundation I am not
aware of. Do what you want. Just know that I would not put my stamp on any
document allowing someone to pour a foundation with an active wet utility
running through it. Abandoned and grouted maybe. But not active. And I have
never met a soils or foundation engineer who would. There is too much risk.
If it were my tower I would move it.
Brian
KF7OVD
On Jan 14, 2014 12:23 PM, "David Gilbert" <xdavid@cis-broadband.com> wrote:
>
> Wrong. No way water that isn't under pressure (it's a passive drain pipe)
> is going to make the soil around his foundation any wetter than it would
> normally get being only 1.5 feet below the surface.
>
> KA5M should do what G4ZTR says ... wrap the drain pipe with something
> forgiving (the thin foil-backed foam you can get at Lowes or Home Depot for
> insulating duct work is cheap and would work fine) and just pour the
> concrete around it. That would be MUCH better than tearing up the soil
> around the foundation.
>
> Dave AB7E
>
>
> On 1/14/2014 11:48 AM, Brian Amos wrote:
>
>> Move the pipe. If it were to ever leak you would have a leaning tower.
>>
>> Brian
>> KF7OVD
>> On Jan 14, 2014 11:42 AM, "John Lemay" <john@carltonhouse.eclipse.co.uk>
>> wrote:
>>
>> Marsh
>>>
>>> The answer to your question is neither !
>>>
>>> No need to relocate the drain, but don't pour concrete directly around it
>>> either. What you should do is surround the exposed pipe with a firm but
>>> compressible material, and then pour the concrete. The material could be
>>> a
>>> dense foam for instance. Alternatively get a piece of larger plastic
>>> pipe,
>>> split it lengthways and place it around your drain with some spacers.
>>>
>>> The intention is to isolate the drain from small movements in your
>>> concrete
>>> base. Also, if you need to replace the drain at a later date, it will be
>>> much easier.
>>>
>>> This is what I would do in a domestic situation. I'm assuming your
>>> building
>>> codes in the US don't have a specific requirement.
>>>
>>> John G4ZTR
>>>
>>>
>>> -----Original Message-----
>>> From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
>>> Marsh
>>> Stewart
>>> Sent: 14 January 2014 16:52
>>> To: towertalk@contesting.com
>>> Subject: [TowerTalk] Drain Pipe Passing Thru Tower Foundation
>>>
>>> I'm installing a base foundation for a US Towers HDX-555. The base will
>>> be
>>> 5' X 5' X 7.25' per specs. The rebar will be per specs. Concrete will be
>>> 4000psi in 28 days. The soil is moist, very firm, and no water is seeping
>>> into the hole. After excavation began, I found a 6" white PVC drain pipe
>>> (rainwater run-off drainage, not sewer) that runs across one corner. The
>>> drain pipe is about 1.5' below grade and runs at about a 30-degree angle
>>> across one corner. Total length of pipe exposed (in the base foundation)
>>> is
>>> about 4'. The rebar "cage" can be built per specs around the pipe. The
>>> pipe
>>> can be relocated, but it will require considerable extra digging and the
>>> soil around the affected corner will no longer be undisturbed.
>>>
>>> Should I relocate the drain pipe or pour concrete around it?
>>>
>>> Marsh, KA5M
>>>
>>> _______________________________________________
>>>
>>>
>>>
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>>>
>>>
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>>
>>
>>
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