Inspection Chamber Regularly Blocked

Deanicus

Our 10 year old house has often had problems with the outside inspection chamber regularly blocking with tissue/waste

It's a 3 into 1 setup, this looks like the one: https://www.wavin.com/en-ie/catalogue/Foul-Sewer/Inspection-Chambers/Wavin-Access-Junctions-WAJs-110mm-160mm/WAJ5-LHRH-BaseAdj-TopFrame-45deg-110

It used to be that I had to hose it out once or twice a year but being largely work from home and the kids, it's more like every couple of months now as the toilets are getting more use (one in particular is heavily used).

There's nothing going down that shouldn't be put down, it's mainly a build up of tissue and waste. It gets caught at the junction point and then starts to back up into the drains. From what I can tell, only 2 of the 3 are in use but need to confirm that.

Apart from hosing it out regularly or going to wafer thin tissue, is there anything I can do to help the tissue etc move along without getting caught? I've always felt that the water doesn't drain out particularly fast and the slow speed contributes as the tissue is barely moving when it reaches this point. We've a 3 storey house and even the water from the top floor seems to go slow enough. Would've thought it would be faster due to the drop.

Any advice appreciated

Deanicus

https://www.boards.ie/discussion/comment/119234409#Comment_119234409

Rats coming in through the sewers is one of my worst nightmares!

I don't think it's an issue for us thankfully, no evidence of it at least. Our AJ was originally situated in soil but we have since paved that section (with cutouts for the AJ) and I see no debris in there but I suppose it could always be further up the pipe. When we moved in we used to get a smell in the downstairs bathroom which was eventually found to be a blockage and was cleared by a drain company (at the builders expense!). Might be worth getting them out for another inspection as maybe it was never fully rectified

Deanicus

https://www.boards.ie/discussion/comment/119235903#Comment_119235903

There's nothing in the AJ where it snags per se. Below is where it collects. Basically wads of tissue are sometimes too big and going too slow to continue down. It then builds up to the point where it blocks the water and it backs up. The angle of entry probably isn't helping either.

I'm hoping there is something I can do to widen this point or put something down there than can help it clear. Wouldn't be surprised if the fall is not right.

Maybe the flow speed is right for relatively modern regs. I'm comparing to my parent's house, built in the 70s, where stuff flies down the drain like a rocket!

If it's not right, I'm thinking either the fall is wrong or there's something up stream that's causing things to slow down. Building waste definitely on my hitlist for that. The smell I mentioned happened from the day we moved in. They changed the durgo/aav valve and it didn't help. Eventually they got the drain lads and sorted it but my thinking is that it's possible all the waste drains have crap in them!

Deanicus

https://www.boards.ie/discussion/comment/119237080#Comment_119237080

Wafer thin sandpaper style in my future me thinks

The Continental Op

Have you put drain rods up and down the drain to see if there is anything obvious slowing the flow down?

standardg60

https://www.boards.ie/discussion/comment/119240191#Comment_119240191

Nah just enforce the two sheets per wipe rule and you should be fine, someone (and kids are maybe being taught this) is being unnecessarily flamboyant

The Continental Op

Modern toilets that flush with the minimum amount of water probably don't help.

Enforce a flush twice rule.

Deanicus

https://www.boards.ie/discussion/comment/119240213#Comment_119240213

I haven't to be honest as I didn't think I needed to. I say it's slow but it could be fine for all I know!

Deanicus

https://www.boards.ie/discussion/comment/119241320#Comment_119241320

My oldest uses decent sized wads, he's a bit of a germaphobe and wants to ensure he gets nothing on his hands! Have tried telling him not to but can't be policing him!

Deanicus

https://www.boards.ie/discussion/comment/119242053#Comment_119242053

Toilets are up to the max. They're all frame hung concealed ones. Think the max is about 7 litres.

The one that sees the most use has always had blocking issues not related to this issue. Always felt that the bowl on it is kinda small so the tissue rarely gets to hit the water before flushing and I think this is contributing. How we know now that the AJ needs a hosing is due to this one backing up. Around Christmas it was backing up and I tried everything to clear it. Last attempt was to check the AJ and I saw it was the culprit

When I used to hose it down before, it was mainly for sanitary reasons as waste would build up there and start smelling around the AJ. It never completely blocked up until last Christmas so not sure what might have changed!

A couple of courtesy flushes might be the answer!

Deanicus

https://www.boards.ie/discussion/comment/119242912#Comment_119242912

I'd need to double check but I think the one most right is unused.

Thing is we have 2 of these AJ in the garden and I don't think anything comes down the 2nd one. It's never really been a problem. I'd need to open them and get someone to run taps/flush toilets etc to see

There is some questionable choices in the plumbing in this house. We have a kitchen gully that doesn't seem to be connected to anything and there seems to be an access point to a drain under the dishwasher but can't say if that is used at all either!

The Continental Op

We have a kitchen gully that doesn't seem to be connected to anything

Thats fairly standard. I get called for a borrow of drain rods by friends locally (rural) and I often go and help out. Never found a kitchen sink that actually went to the septic tank yet. The other classic I often see is a septic tank thats been installed the wrong way around, inflow below level water level and out flow above - should be the other way around. For the old concrete tanks it seems to be a worse than 50/50 chance that they are ever put in the ground the right way around.

yoyo

https://www.boards.ie/discussion/comment/119236015#Comment_119236015

Sorry for bumping this older thread but I have the exact same issue with a junction like this (only 5 year old house). I have to frequently hose it down, paper is always getting caught in the RHS drain and this then causes it to block completely. I notice it when toilets start to drain slower thankfully so it's never got too extreme.

I am putting it down to useless modern "eco" toilets and also I don't think the drainage pipe was installed very well, on a decent slope. I notice running water through it the water goes at a very slow pace.

A blast of the hose will clear it and in the second inspection chamber (shared one) the water runs freely into the main sewer with no blockages.

Is there something I am missing here or is it just a rubbish installation (I've had some issues with plumbing in this house since moving in, so I don't rate the workmanship highly). I use the bog standard (pun intended!) Tesco toilet roll, nothing fancy like quilted. I don't flush down anything I shouldn't either. I see no evidence of rodent activity in the chamber either, or droppings.

I don't really want to pay some lad to come out just to state the obvious. As I can see where the blockage exactly is occurring, I doubt there is a need for a full drain survey?

The Continental Op

Another possible cause of blockages is if the water + sh1t + toilet paper is flowing too fast and is coming in from a side channel. It hits the far side and some of the paper gets stuck. If there isn't much other flow in the pipes the paper will stay there and slowly build up.

If the main flow is from one of those side channels if there isn't enough flow of water there's a chance it will build up on the opposite site.

10-10-20

(I don't know why this text is being quoted...)

I had this for 5 years on an AJ around the back. I used to hose it down every 6 months to prevent a blockage. Drain-guy told me that the down-pipe was too close to the AJ and to move it back. So I did. I was lucky as the side of the house still had a compacted stone path rather than poured concrete.

Measure the distance from the AJ to the down-pipe and I think it's supposed to be greater than 2m away. If it's any less then the slosh tends to cause the paper to perch on the shoulders of that dead-space in the AJ and it collects and falls in as one large mess later on.

yoyo

Thanks for the comment guys. I attach some photos of my AJ and also a video showing it draining water here (it's cleared so nothing nasty don't worry :) ):

https://photos.google.com/share/AF1QipOprw9j6X8jkvKzp28UFumNoQ7iFMHq5az9vHZYpL9c6pp0bblCA6jeNnJN866Qfg?key=QWdZZ3NBUm4zTlF1WkpxcU0zYkdWdTNkWEpuUlZn

The house has all internal toilet pipes so no outside waste pipes. I notice a bit of a ridge/gap next to each channel. Should it be like that or is it misinstalled? The draining also seems to be very slow. Of course flushing toilet should leave more momentum but even at that it is slow to drain

Deanicus

https://www.boards.ie/discussion/comment/120411636#Comment_120411636

Your setup is very similar to my own

Think the issue for me is the angle as per The Continential Op as mine does come in at an angle. The distance to the AJ as per 10-10-20 might also be an issue. Like you, my downpipe is internal and I have no idea where in the property does it enter the ground so hard to know the distance

In general though, my issue has subsided a little. We changed toilet paper brands and it is much better. Haven't had a blockage since then although I do probably need to hose it out for sanitary reasons

yoyo

https://www.boards.ie/discussion/comment/120411802#Comment_120411802

That's good to know Deanicus, I just use Tesco paper. Might try another brand. It really is such a random issue I think 2m distance this is on point. Likewise not something I could confirm unless getting a cctv survey done..

10-10-20

https://www.boards.ie/discussion/comment/120411636#Comment_120411636

Yours looks slow. I'd guess it might have sufficient drop, but it could be a catch-point for paper alright.

https://www.boards.ie/discussion/comment/120411802#Comment_120411802

Yes, the paper brand does matter - the quad-ply is commonly an 8-sheet affair (disassemble it and you'll see!) and it's a demon for getting bodged in pipes in my house. It's not unlike kitchen-roll in some ways. I had to mandate Dunnes' basic ply to the populous who fill the privy middens. ;)

monseiur

Not a permanent solution to your problem but if you have a second toilet in the house get into the practice (when circumstances allows) of flushing the second toilet just after the one you just used, the extra gush of water will help push the contents - solids & paper on their merry way (The greens will love you for this 🤣 )

yoyo

https://www.boards.ie/discussion/comment/120418579#Comment_120418579

The fact these modern "eco" toilets require so much flushing I'd say if you calculated the litres of water used the old school ones would come out more Eco! :D

Lewis_Benson

Older toilets have a much better flush, the new eco toilets would have you <MOD: snipped out some crude language> unlbocking drains all day.