The HOA just sent out an email that there has been a sewer collapse and
that the city was working on it. The city told the HOA that some might
have problems with sewer gas getting into the house during the fixing
because the workers would create a vaccum that might pull the water from
the pipes in the house and that we should run water if we smelt gas. How
far away from the construction should I be before I don't really need to
worry about it?
Statistics are like bikinis. What they reveal is suggestive,
but what they conceal is vital.
According to the laws of physics, perhaps you're correct. Highly
unusual for it to occur though if the caveat "PROPERLY VENTED" is accurate.
I wonder though if the city was actually cautioning him about the storm
sewers. Floor drain in the basement is generally (again GENERALLY) not
supposed to be tied in the the sanitary sewer line which is vent,
however it if is -as may well be the case here (hence the city's
concern) - I don't think that that sewer drain is tied into the vent
stack in the house. Perhaps it's supposed to be but I've seen too many
where it's not.
If I was the original poster, I would check to make sure there's water
in the p-traps and if I wasn't absolutely sure that the basement drain
was NOT connected to the affected line, I'd install a pressure plug
until the crisis passed so that whether they suck the line clear or try
to blow it clear, the crap would take the path of least resistance and
not fill up my basement.
Wonder if area had heavy snow fall plugging up the vents?(remote chance)
Sewage back up is covered by insurance. I have check valve installed on
my basement drain. Here in June we had biggest flood in 45 years. My
daughter's basement was total loss due to sewage back up. Tallied damage
was almost !00K which insurance co. paid reluctantly. Feel sorry about
folks who suffered over flowing surface water damage. Daughter had a
sump pump but when power went out... Now she has new pump with battery
and gen set back up installed for the next time in case...
There is an emergency sump pump system that's run by city water. I
looked in to getting one for an old(90) customer of mine before I became
too ill to do physical labor. ^_^
See if you can remove the grate or drain screen on your floor drain.
Most are removable.
Any Big Box or decent hardware store will have a suitable plug in the
plumbing section. It's nothing more than a 3" high or so rubber "cork"
slightly smaller in diameter than the sewer pipe. The rubber has a
metal "washer" on the bottom and top and a threaded rod in the center.
You insert the plug in the sewer/drain and snug it down with a wrench
which expands the plug (the outside diameter of which has little rubber
ridges to grip tightly) and effectively closes off the drain. Nothing
passes either way.
On Tuesday, December 17, 2013 11:47:32 PM UTC-5, Unquestionably Confused wrote:
The only way it could happen would be for there to be a vacuum
large enough so that the air from the various vents would not
be sufficient to reduce it enough and there was still enough
vacuum to pull the water from the traps. Given that we're not
talking about just one house, but presumably many houses, it
would sure seem to me that either a lot of houses would have
to have no venting or it would have to be one hell of a vacuum
being created on the sewer main. I don't see why they would be
creating any substantial vacuum to begin with.
On 12/18/2013 8:25 AM, email@example.com wrote:
If they are working in a primary chase, they will want to rapidly
remove the toxic gases (will kill you if inhaled) out of the
system as rapidly as possible, and keep a fresh air inlet open
while the vacuum is applied. A lot of this is overkill, but the
hazard is there.
Or, until the trap is empty enough to allow air from above the trap to
pass through. This would break the siphon, and any further water
evacuation would be via venturi like mechanics. A strong enough
air flow could possibly lift ripplets of water and take them away.
Plus, the air flow could increase evaporation.
On Wednesday, December 18, 2013 11:40:27 PM UTC-5, Irreverent Maximus wrote:
Also I suspect water in a trap is not an impenetrable barrier to gases.
I shouldn't say what my evidence is for that.
Oh, all right, I will. When I was in college I once saw a gadget the kids called a bong, I dunno if it has an engineering name. I'm not sure the usage is entirely legal.
It had a trap filled with smelly water, but differential pressure was sufficient to pull heated air through water and out the top.
I've also run into a case where the exhaust fan on a bathroom seemed to be able to pull sewer smell up through traps even though they were kept full. The door fit too tightly and/or the fan was too strong.
On Thursday, December 19, 2013 8:36:59 AM UTC-5, Unquestionably Confused wrote:
Sigh, and completely different settup. It's kind of the reverse of a
P-trap. It's designed to let AIR pass through water. If it was
designed like a P-trap with a blocked vent, you'd be sucking the
water out until you finally got to the air.
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