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IBB Plumbers - Intermittent Toilet Back-Up Issues - Possible Causes?

giles45shop

Red Skull Member
Joined
May 24, 2020
Member Number
1336
Messages
114
Loc
Odessa, FL
My house was built in 1957 and had cast iron drain plumbing (pressure side is galvanized). There are two bathrooms which are relatively close together and the septic tank is only 10-15 ft from either bathroom. This is a normal below grade septic tank and no raised mound or transfer station. Tank was pumped a couple years ago and the drain field is ~ 50' of Infiltrators in sugar sand. I've lived in the house my whole life and during that time it's only had to be pumped maybe half a dozen times in 60 yrs. Several of those were associated with drain field clogs and I replaced the drain field from the original orange clay 6" pipes to Infiltrators and did replace infiltrators once (~ 2-3 yrs ago) due to root clogs.


There's three people in the house, myself and two women (wife, daughter). Yesterday, one of the toilets backed up, but didn't overflow. It went down slowly over 15 minutes or so. I took a toilet snake (~ 4 ') and ran it down and didn't see any whoosh of flow like you might if a clog had broken free. I then rapidly poured ~ 2 gallons of water into the toilet with a 5 gallon bucket and repeated that ~ 3X. There was a bit of gurgling, but the water went through the toilet as fast as I could pour it. Afterwards, I flushed it normally a couple times and all seemed normal.

No issues for rest of the day and my wife took a shower last night w/o issue. This AM I used the toilet and it worked normally. A little later, both wife and daughter used the toilet near simultaneously and both toilets backed-up but did not overflow. Same symptoms as yesterday. They went down after 15 minutes and I snaked both with tilt auger w/ no obstructions noted. Poured about 8 gallons down each (~ 2 gallons at a time) and they seemed to flow fine. I did see a little back-up into one of the tubs when I poured the first couple gallons, but it went right down and did not repeat on subsequent pours.

Went to the roof and shined a flashlight into the vent. One vent I could see straight down to the water at the bottom, the other appears to have an offset just below the roof line so I couldn't see if it was clear.

Should I try running a water hose down the vents to verify they are clear? If they appear to be clear, any thoughts on next steps to troubleshoot or actions to take? Trying to take smart steps before digging up the septic tank and/or taking off the toilets, renting a power auger, etc.

Wife is freaking out as we have company coming over this afternoon, but fortunately the house has a third bathroom that is on a separate septic tank that we can use as a fallback plan.
 
We have had ours back up about once a year. After some investigation I have determined whoever tied our waste drain into the city sewer was retarded and was trying to make shit flow uphill.

Someday I might did everything up and redo it. My cure for the time being is a bidet and wet wipes. No paper gets flushed.

I haven’t had to snake it for about 2 years, so I guess it’s working.
 
would suspect that there's a restriction further up the line near the tank.
works fine until your usage fills the pipe.
then slow drains.
give it long enough and the pipe empties, then works fine until pipe is full again.
I had a similar situation with a root mess in mine. Everything worked fine, but run the washing machine a few times and suddenly the floor drains ran super slow.
I'd rent the electric eel for an afternoon and snake the whole deal.
 
87manche said:
would suspect that there's a restriction further up the line near the tank.
works fine until your usage fills the pipe.
then slow drains.
give it long enough and the pipe empties, then works fine until pipe is full again.
I had a similar situation with a root mess in mine. Everything worked fine, but run the washing machine a few times and suddenly the floor drains ran super slow.
I'd rent the electric eel for an afternoon and snake the whole deal.
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I was thinking that, but what confuses me is that the run to the septic tank is short and flushing 16 gallons of water down it should have filled up the pipe and caused a back-up - which it didn't? Overall, probably a good idea to snake it regardless.

M92PV4U said:
Females overuse toilet paper.
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Definitely agree with that. I've seen the wad of paper they pull off to wipe after peeing
Jackie Treehorn said:
If you can see water down a roof stack vent your line is not clear. The septic tank is full or there’s a blockage in the lateral line.
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I was wondering about that. Do you think I should try running a hose down from the roof stack to see if it flushes through/fills up or should I try a snake instead?
 
Cast iron pipes tend to be less smooth inside after awhile.. grabs onto paper..

I know from first hand experience that something like a pencil can lodge itself into a turn in the toilet or maybe pipes and be very difficult to figure out.. moves water just fine, but grabs paper.
 
urjb said:
Cast iron pipes tend to be less smooth inside after awhile.. grabs onto paper..

I know from first hand experience that something like a pencil can lodge itself into a turn in the toilet or maybe pipes and be very difficult to figure out.. moves water just fine, but grabs paper.
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That could make sense. These pipes are almost 70 years old and that coupled with the females heavy use of paper could have created a situation where the paper piled up enough to slow things down with a normal flush, but then the "power flush" with the 5 gallon bucket is enough force to break things free. Both of them just took long showers and nothing seemed to back up.
 
giles45shop said:
I was thinking that, but what confuses me is that the run to the septic tank is short and flushing 16 gallons of water down it should have filled up the pipe and caused a back-up - which it didn't? Overall, probably a good idea to snake it regardless.


Definitely agree with that. I've seen the wad of paper they pull off to wipe after peeing

I was wondering about that. Do you think I should try running a hose down from the roof stack to see if it flushes through/fills up or should I try a snake instead?
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But it's not going to fill just the run to the tank. It's going to fill every bit of pipe below the toilet.
You said you saw it back up into the shower. Pipes not flowing.

With such a short run maybe sacrificing a cheap Amazon endoscope to the shit realm is worth it.

Does it have easily accessible clean outs or are you pulling a toilet to get in there?
 
giles45shop said:
I was wondering about that. Do you think I should try running a hose down from the roof stack to see if it flushes through/fills up or should I try a snake instead?
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All you’re likely to do with a garden hose is add more water to an already full pipe. I’d snake it then run a camera down it, or pull the septic tank lid to see if it’s overfull.
Grnjp92 said:
Run a camera down the line. My chick had a case where the main sewer line had settled a couple inches.
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Sewer cameras don’t see through dirty water. Got to get the clog out of it or empty the septic tank first.
 
You have a restriction down the line you are filling up the main pipe/stack and then the added pressure is causing it to drain past the clog but not actually clearing the clog.

Could also be a plugged vent but that’s not as likely as a blockage in the cast.

All cast that was flowing once snaked but was clogged from cast itself corroding.

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My cast iron pipe ended up having a rise between the stack (that the sink drains into) and the vertical pipe where the toilet connected. It would hold enough water to cause air bubbles in the toilet if the sink was recently used.
 
Did your women switch from the cheap paper to the expensive paper? The cheap shit falls right apart in water as toilet paper ought to. The fancy shit creates all sorts of problems in marginal systems because it stays together way better and doesn't break apart.
 
billdacat said:
Dang.... Reminds me of my apprentice days helping my uncle circa 1970's. Cast iron was a damm good money maker. Steel pipe was next in line. :smokin::smokin::smokin::smokin::smokin:
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We had a plan to redo the outside to the septic tank one day and replumb under the house the next. When we cut the main line loose everything under the house fell and broke. The only support was where it was going through the wall, all of the other supports had rusted away but were still in place. :homer: We worked on that project from 9am until 10pm.
 
Grnjp92 said:
Run a camera down the line. My chick had a case where the main sewer line had settled a couple inches.
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I usually find this when the clog is outside the house. Pipe settles and takes awhile to start becoming a problem.
 
cj3a said:
I usually find this when the clog is outside the house. Pipe settles and takes awhile to start becoming a problem.
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That was the case, she had it snaked a year ago, then a couple months ago, plumber got his snake stuck and had to get in the main line to get it. Found out at that point the main line had settled
 
Sounds like you've got a shifted/settled pipe in the ground, or a foreign object got in there

I've pulled (well not all of them came out the way they went in anyways) all sorts of stuff out of sewers. Pencils like mentioned, plastic army guys, door knobs, underwear and socks, enough tampons to build a really nasty snowman (literally several 5 gallon buckets worth), pounds and pounds of paper towels.

My favorite was a flat prybar that was found in one of the worst sewer runs I've ever seen. That one exited the house to the north, cut back east, then back south and ran all the way back past the house. Was something like 175' of sewer. We found the prybar under the driveway, of course. We ended up running a large head on the snake and pushing it into the city main.

Speaking of all that, I assume you all know not to flush tampons seeing as how you're on sceptic anyways, but definitely ask. Those things cause a lot of these issues. A lot.
 
So just following up on this - We all took showers and had 10 people over for dinner with lots of bathroom use and everything seemed to be working fine w/ no evidence of back-ups, slow flushes, etc.

At this point, I'm still not sure what the issue is. I suppose the most likely scenario is some type of partial obstruction in the line between the house and the septic tank, but I don't understand the intermittent nature. We haven't change TP brands in years and the daughter knows not to dispose of anything down the drain/toilet (wife is post menopause). I'm a little hesitant to auger it due to risk of penetrating the old pipe and making things worse. There's also no easily accessible clean-outs., so I will have to pull both toilets as well. May let it ride for a bit and see what happens.
 
giles45shop said:
So just following up on this - We all took showers and had 10 people over for dinner with lots of bathroom use and everything seemed to be working fine w/ no evidence of back-ups, slow flushes, etc.

At this point, I'm still not sure what the issue is. I suppose the most likely scenario is some type of partial obstruction in the line between the house and the septic tank, but I don't understand the intermittent nature. We haven't change TP brands in years and the daughter knows not to dispose of anything down the drain/toilet (wife is post menopause). I'm a little hesitant to auger it due to risk of penetrating the old pipe and making things worse. There's also no easily accessible clean-outs., so I will have to pull both toilets as well. May let it ride for a bit and see what happens.
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You can cut the castiron pipe and install a cleanout, preferably where you think that it is plugged. Just add the apporate tee and some fernco coupling. Make sure that the pipe hangers are in good condition before messing with the pipe.
I wouldn't do that until you have a problem though.
 
M92PV4U said:
You can cut the castiron pipe and install a cleanout, preferably where you think that it is plugged. Just add the apporate tee and some fernco coupling. Make sure that the pipe hangers are in good condition before messing with the pipe.
I wouldn't do that until you have a problem though.
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No hangers involve here, this is slab on grade, so I am potentially digging under the slab and/or busting concrete depending on where the restriction (if there really is one) is located.
 
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