drainage problems PLEASE HELP !!!

for a couple of days we have been getting a slight "gurgle" noise in the shower when we flush our bog. all waste is getting away or so it would seem.
as we have only been in the property a few months and becasue there is a septic tank in the field (40m away).
i lifted the lid of the drain in the courtyard to see if the tank had backed up (which is where it manifests itself when it does by all accounts)..... but it was as clean as a whistle.
we share this drain with two other properties. i have got them to flush bogs/run taps and they both ran through with no bother. when we flush bogs/run taps it's seemingly not getting though to this main drain.......
there are two infeeds to the main drain, one of which runs for each of our neighbours when they flush. so we must join with one of our neighbours somewhere earlier in the pipe (or perhaps later read on). i shoved drainage pipes up the pipe to see if i could dislodge any obstruction yesterday, to no avail.
anyway not knowing much (anything) about what i'm doing apart from having an ability to shove crap down the pipes with a rod if they're blocked i called a man with a camera to investigate as it would seem that the waste from our house is not getting to the main drain.
he shoved a camera up the pipe which we thought would be the one that ours joined for about 20m without it showing a join so clearly (his words) we join the other one if we join with anyone before this main drain.
when he shoved the camera up the other pipe in the main drain he found another drain just 2m away (the additional drain cover is not visible from the surface and my nieghbours with the metal detector are out). basically i think we may be in the sh1t pretty soon........
is it normal for a drain clearance guy not to investigate the problem from inside the house (i.e. shove some kind of equipment down the sh1tters etc) before suggesting that he digs up my garden to break into the pipe to get to the bottom of the problem ? i simply don't know and i'm mindfull that this could be an expensive job running into thousands to get put right, but i don't want to get ripped off.....
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snipped-for-privacy@btopenworld.com says...

snip
I've never heard the term "bog" used for this, but since you're talking about flushing, I'm thinking you're talking about what I'd call a toilet (or throne, ha!).
Here's my opinion: the gurgling sound in the shower trap sounds to me like a blockage in the vent, not the drain. For water and excrement to go down the drain, air needs to be able to enter from above. There should be at least one vent pipe coming through your roof. If it is blocked, the air has to get into the drain someway. Therefore, you're probably hearing the air being sucked through the water in the shower trap.
Unless somebody already checked this and it is clear, I'd go after the vent FIRST. You can use a vent snake on it. Or do as a lot of folks around here - stick a hose into the vent and try to clear it out. (Not just with the hose; I mean turn it on and run water through it). Or even take a look with that camera thingie you were referring to.
But (personally) I wouldn't even look at a shovel until after checking the vent.
good luck!
steve
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wallyl wrote:

Gurgling is an indication of a air problem. But if its only slight, perhaps the gurgling is at a remote spot. Still an air problem. Check the vent.
As for the camera, I had one company come out to my house and this rookie couldn't get the camera down any of my pipes. I got another company and insisted they send me a veteran and train the rookies on someone else. This guy was the truth. Marked out where significant turns or things were in my pipe with some finder tool. Really help me out with understanding my plumbing system. And took his time. That guy was a real plumber, arse crack and all, lol. My problem was solved and I am confident I can identify solutions to future problems with my new knowledge.
Im starting to think the arse crack is a way to get you to leave them the hell alone while they do their work :)
--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
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thanks both - managed to confirm that our waste is making it to the septic tank - by another route would you believe. called the drain guy off (still cost me 60)..... looks like an air problem. will get help from neighbour tonight cheers.
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