Sewage SOS

[vivienz]

Can anyone point me in the direction of an idiot's guide to the kit needed for all the foul water kit that I need to have in between the pipes coming out of my slab and into the sewage treatment plant?  I'm thinking of things like inspection chambers, risers, joints, pipes, etc.

 

The reason behind this is that my external foul water drainage was due to be done imminently but the figure that my groundworker came back to me today is astronomical.  I suspect that he has loaded the quote on materials and need to price these up to see whether I'm being tucked up or, in fact, I've greatly mis-judged the cost of this part of the works.

 

 

[PeterW]

How long..? How far..?

 

if it’s just pipe runs then £6/m for pipe plus £4/m for bedding. An IC should be change of £70 with lid and riser to 800mm. Suggest you bring all together into one big 450mm IC and then put a smaller 300mm IC as a rodding point just before the sewage tank. 

[Russell griffiths]

Do you have a drainage layout drawing 

its not that expensive all the pipe and fittings if you buy from an online retailer, but if he has priced it from travis Perkins as he thinks that’s what you would do it will cost a fortune. 

In an emergency I had to get a fitting from travis Perkins it was £24 the same part online was £8 

 

[vivienz]

Thanks both.  Drainage plan attached. Note that there is no rainwater harvesting reservoir and that the perimeter drain does need to be a French drain due to our heavy clay.

 

We had a reduced dig to 800mm all around the house already for the foundations, so there is no need for the pipes to be concreted in as this only applies for <600mm cover.

Drainage plan.pdf

[ProDave]

What has he quoted you?

 

Is the drainage field OUT of the treatment plant done yet? That could be more expensive than the pipes to connect IN.

[PeterW]

Trigger happy architect there. Don’t need half those ICs drawn. 

 

Only odd thought is that if you have no rainwater harvesting tank, where is the soak away as that seems to run to a grass outlet ..???

[vivienz]

The soakaway isn't a soakaway as we are on clay.  The far end of the garden runs down into a ditch, which is where (eventually) most of the land drains discharge to.  I think that even if we had the reservoir, it would still need to follow that drainage path when it became full.  We have no requirements for a soakaway or drainage field from the PP, and the BCO was happy enough with the proposed drainage plan.

 

At this stage, I'm trying to get an idea of what the materials (including sand, etc. for backfilling) are likely to cost as I'm making an assumption of 2 weeks' labour for 3 people as well as 3 loads of muckaway.

[PeterW]

Are we just talking 800mm trenches here ..??

 

should be less than a load of muck away (assuming treatment plant is in..??) as you should only be getting a cubic metre of spoil per 8m of dig out if they use a 300mm bucket. 

 

What is the detail planned for the bottom of the downpipes..? Is it gulleys with shoes, or straight into the ground..?

 

[vivienz]

Yup, 800mm trenches. The muckaway comes from digging out the old septic tank and the hole for the sewage treatment plant (not in yet).

 

No detail planned for the downpipes yet as I didn't think it was something I was going to have to ponder too hard on myself.

[recoveringbuilder]

We bought all our pipe and most of fittings and inspection chambers from an online company called build plumb plastics, I’d need to look at receipt but I’m sure we got 150 m of Brett Martin pipe for around £300, hubby did all the drains along with the digger driver who was really good at getting off his machine to help and it was all done in 6 days that included putting in the sewage treatment plant,

[vivienz]

Thanks, Christine. I'm pretty sure that, sadly, I'm being tucked up here. It's very disappointing as the groundwork team have been very good up until now but he seems to have succumbed to temptation on trying to price an all-in job at way over what's reasonable.

[nod]

Sadly I think this is the point I’ve made on several occasions 

Selbuilders read Spons contractors don’t Most seem to base there prices on how much work they have in at the time 

 

It would be worth taking your drainage drawing into your builders merchants Preferably where you have an account 

Most will give you a detailed quote for all materials 

Then at least you will know exactly where you are at with laboure and materials 

 

I suspect that if you where building half a dozen houses His drainage quote would be more in keeping with the rest of his work 

 

[ToughButterCup]

26 minutes ago, nod said:

[...]

I suspect that if you were building half a dozen houses His drainage quote would be more in keeping with the rest of his work 

[...]

 

That factor is so important. Unless you are a serial selfbuilder ( @Stones for example ) you are highly unlikely to be a repeat customer. 

Most of us here are ordering more wood / blocks / screws / plasterboard than we have ever done. But only a few grands worth.

Once.

And that's it. 

There's so much 'normal'  work around that self builders have become the icing on the cake for a few tradespeople.  SPONS is an excellent guide. But that's all - a guide.

[newhome]

Bugger! Still, you’re not tied to him presumably so time to start getting a few more quotes. 

[ProDave]

+1 for buying from Build Plumb Plastics, that is where our drainage stuff came from.

 

Make sure you get the treatment plant fitted correctly, i.e. concreted in if you have a high water table.

 

Don't forget a SWA cable to power the treatment plant while you have the man and digger on site.

[Ian]

@vivienz

Just a couple of things for you to check:

• the sewage treatment plant needs to be located at least 7m from the house but, in my view, the further the better if you have enough land as they can be a little noisy and the large lids are not usually pretty to look at.
• You need a small inspection chamber on the outflow pipe from the sewage treatment plant (unless your model of plant is one of those with the inspecttion point built in)

Edited February 12, 2019 by Ian

[vivienz]

3 hours ago, nod said:

 

Selbuilders read Spons contractors don’t Most seem to base there prices on how much work they have in at the time 

 

 

 

I have based the labour costs on the day rate he charges me and for the estimated (by him) duration of the job, so there is no ambiguity there or interpretation from SPONS. My sewage treatment plant has already been purchased and making a decent allowance for plant hire (i had the same equipment not that long ago) and some muckaway, it still gives a materials cost of 6k which I simply cannot see at the moment, hence the original question about what materials I'm likely to need.

 

[recoveringbuilder]

Wow! That’s some money, if I were you I’d go through that drainage plan and cost everything that’s what we did and although we had to go back and get a few more fittings it was nowhere near that amount, probably about a third of that at the highest!

[vivienz]

42 minutes ago, Christine Walker said:

Wow! That’s some money, if I were you I’d go through that drainage plan and cost everything that’s what we did and although we had to go back and get a few more fittings it was nowhere near that amount, probably about a third of that at the highest!

 

That's what I thought and why I wanted to check things out.

[ProDave]

Ask him for a breakdown of how he arrived at his price, then start "discussing" it.

[PeterW]

So at a worst case, assuming 3 large and 3 small ICs, 30 bends, 6 hoppers, 80m of pipe, plus 10 tonnes of Gravel, I’m getting to £1650 give or take. 

[Mr Punter]

Why not ask him to quote labour only?

[vivienz]

9 minutes ago, Mr Punter said:

Why not ask him to quote labour only?

 

That's the route I will take.  I said to him at the time that I'd prefer to do it as a day rate, as we've done for everything else, and I'll source the materials.  This makes sense, anyway, as he isn't VAT registered and I wouldn't be able to reclaim it if he bought them.  I'm still really disappointed that he's so obviously loaded this to such a degree when we've given him virtually all the groundworks for the site.

[Wagas]

59 minutes ago, vivienz said:

 

That's the route I will take.  I said to him at the time that I'd prefer to do it as a day rate, as we've done for everything else, and I'll source the materials.  This makes sense, anyway, as he isn't VAT registered and I wouldn't be able to reclaim it if he bought them.  I'm still really disappointed that he's so obviously loaded this to such a degree when we've given him virtually all the groundworks for the site.

 

What's he charging as a day rate out of interest?

[vivienz]

For a 3 man team, 1 labourer, 1 on the dumper and 1 on the digger, £415per day.