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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> persistent blocked sewer https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1426941668 Message started by Natedog on Mar 21^st, 2015, 12:41pm

Title: persistent blocked sewer
Post by Natedog on Mar 21^st, 2015, 12:41pm

We've always had problems with drains blocking up ever since I've been here. I thought I had found and cured the problem (a collapsed pipe under where I used to park my lorry) but a couple of days ago there was that familiar pooey smell outside. This time, the block was actually visible in one of the manholes.

There is a half pipe running front to back which carries the foul from the main soil stack. There is then an angled half pipe entering from the side which is a bit higher up. This is fed from the gulley that takes the washing machine waste.

What seems to be happening is that the main front to rear half pipe is covered in a thick build up of what my neighbour described as 'shale' (sh*tty limescale) and if a particularly large lump of solid waste comes along, it gets wedged between the bottom of the half pipe it is in, and the side entry from the gulley. This then backs up everything behind it.

I've tried scraping this stuff out with a spade, but it is very solidly in there. Is there any industrial type descaler stuff I can put in there to clean it out, or am I gonna have to fork out for someone to come and jet them out?

Title: Re: persistent blocked sewer
Post by Headrush on Mar 22^nd, 2015, 12:13pm

A strong solution of caustic soda might do the trick. What's it like at the next manhole down? Maybe you could bung it up somehow to help contain the caustic soda solution, otherwise it will just run away and not do very much. Unfortunately if there are many users upstream from you then blocking the main sewer is probably not option..

Title: Re: persistent blocked sewer
Post by woodsmith on Mar 22^nd, 2015, 2:05pm

I've had this stuff build up in the trap in the loo and left it soaking in neat caustic and it did nothing. In the end I chiselled it out and it came away like stone. Unless it is easily accessible I'd get a drain cleaning firm in, they are used to dealing with this and have the gear to clean it out thoroughly.

Title: Re: persistent blocked sewer
Post by thescruff on Mar 22^nd, 2015, 6:26pm

If, it's the inspection chamber thats causing the problem then grind any ragged edges off.

Must likely probems is.

1. sanitary towels.

2. nappys.

3. fall too great and the water is leaving the solids behind.

4. A collaspsed or blocked pipe down stream.

Turds will not cause a blockage as soon as you get a build up it will either push or flood over, even more so in an open channel

Title: Re: persistent blocked sewer
Post by big_all on Mar 23^rd, 2015, 8:54pm

as an aside

if a drain is shared by 2 or more properties they are now the responsibility off your local water company

Title: Re: persistent blocked sewer
Post by Natedog on Mar 24^th, 2015, 10:01pm

this section is shared by 4 properties. local water company aren't interested in preventitive maintenance. they will just come and clear it when it blocks. seeing as it is on my drive, and i can clear it quicker than it would take me to ring up and report it... you get the idea ;)