epsilonGreedy

I like it, suitably low-tech for me.

Yes I had the same concern. When pushed fully home the plastic joints are pretty seamless. The video I watched did involve drainage bridging over footing blockwork and it emphasized that plastic drainage should not be subject to any stresses at joints when the ground moves hence the pullback technique. I guess it is a trade off between best seamless joints and zero worry about plastic crunching stresses at joints should there be some ground movement.

I got the advice about pulling back the joint a touch from a YouTube instructional video produced by one of the large UK manufacturer of underground drainage. Also the old-time semi retired builder who helped me during the early stages of the build demonstrated the same technique as he was laying the main foul drain onto my site.

Swmbo has not smiled for 2 weeks so I need to get a foul drain connected to the static caravan asap. Yesterday I realized there is decent fall from the FFL of the static caravan to my mains sewer connection some 15 meters away on the far side of my existing footing blockwork. As a result it will be possible to lay some conventional rigid plastic underground piping across the top of my footings blockwork for a couple of months while I dig the long term drainage to plan and then link this to the static caravan via a spur trench. The problem I face is connecting the last two feet between the deeper mains sewer pipe and the temp plastic 110 pipe spanning the top of the footings blockwork. In 2 feet I need to drop 320mm and also perform 320 degree turn a like a helta skelta for sewage. What type of flexible pipe should I use for this connection?

Just looking for some practical tips on cutting underground drainage pipe, eg saw type and particularly how to obtain a 90 degree cut. I understand that when joining push-fit foul drain pipe sections it is good practice to push a coupling fully home then ease it back 10 to 15mm so that any ground movement does not stress the joint. From this I infer that pipe cuts do not need to be millimeter perfect but a cut 5mm out of true from a square cut would be a long term liability to seal integrity.

Are so that explains why they are the default offering on the shelves of my local BM. More walk-in plumbers working on older properties than new builders.

Thanks for the warning but I reckon I am ok. The water pressure here is so high that yesterday I was able to jet clean some old paving slabs at mains pressure using just a multi spray pattern garden hose head on the single jet setting. The final underground mains water route is just 4 meters from plot boundary water meter to kitchen entry point. I need 20m to get from the builders supply stand pipe to static caravan, another 5m to bring mains water from utility room to he remote garage and then at an intermediate build stage I will need a 10m spur from the static caravan supply to the garage before the main house build commences.

Now ordered. I understand Philmac is another respected brand and is to be preferred when coupling with older generation plastic piping.

I would have probably discovered that technique after my first attempted coupling started hissing and leaking at mains pressure. ? Anyhow I expect some posh shears to arrive tomorrow for less than the hourly rate a plumber would charge to fix my hacksaw budged joints.

Good point, I was not thinking beyond mains pressure water piping. I'm sold. Just completed the Pipestock order before their 3pm deadline. Let's see if 50m of water pipe plus shears gets to the middle of nowhere in Lincolnshire tomorrow as advertised. The Plasson pipe shears were £28 not the £40 I mentioned, I was looking at the non discounted column on the Pipestock web site. You know where to come if you need to borrow these, can also offer a 12 ton jack for static caravan leveling if needed.

For a single self build do I need to shell out £40+ on proper ratchet pipe shears? If not would a careful hacksaw cut be ok?

Pipestock is a great find and generous with self builder advice on the phone. Just filling out the online order now and looking for a recommendation on which brand of underground 25mm blue MDPE couplers in a high water pressure area. Plasson?

Thanks for the clarification. Multiple AAV's for each toilet are a bit of a problem for a static caravan if I am correct in assuming they must be above pan level. I will run the main soil pipe along the centreline of the van which will reduce the toilet horizontal runs to less than 2m. Then at the starting point of the main pipe I will route the pipe outwards and upwards to say 600mm above floor level and cap this off with an AAV. The pro team who installed my neighbour's static drainage considered this a real problem to solve, their grey water drains along a parallel pipe mounted above the foul drain. The grey water then falls into a gulley with water trap before merging with foul pipe. When buying some second hand steps from a holiday park owner in Skegness he was generous enough to give me a lesson on static drainage planning for the whole park. He thought the grey/foul merge under a van via a gulley was overdesign but then he did add that that positive pressure concerns were addressed by two vented soil stacks at downstream locations across the park.

Where are the puddles or do you benefit from a micro climate in your part of Lincolnshire? ?

Let's assume I will pick it up from the BM as a coil.

That sounded counter intuitive on first read but after a few minutes thinking and visualizing I get it. So the issue is the velocity of the slug but not to prevent main pipe blockages but instead the design challenge is to clear the pan fast enough before the flow rate of the fresh flushing water reaches maximum? Your post might trigger a redesign of my under static foul drainage because if I follow my neighbour's design there would be a 3m horizontal run from pan to the main foul pipe where the AAV can provide a benefit albeit after a post flush delay.

I agree, I was just illustrating minimum set up costs for a "scratch design" system. Your £2800 estimate for batteries is better. "Golf Cart" batteries are often mentioned in sailing forums though this could be an American focus. I have heard about a requirement for periodic deep discharge to restore the surface of plates, even so this does not change the capacity planning maths. I suppose it depends on whether the diesel generator kicks in to handle high load periods. This then leads onto another debate about providing enough charging load to provide a healthy level of work for the generator engine as diesels do not like prolonged low loads. The problem is compounded by the fact that wet acid batteries soak up amps at a much lower rate when topping up from 85% to 100% charge. If I was the OP I would be looking at a large battery and invertor capacity to handle max load and a smaller generator capable of generating the worst case winter whole day consumption over 6 hours. Couple that with 4 Kw of PV and the generator might not kick in for 6 months of the year. The notion of UFH via air source powered from off grid electricity in anything less than a passiv house sounds a little nutty to me, though this is based on intuition and not maths.

My self build neighbour let me crawl under his static caravan to make notes on his pro installed grey & foul drainage. Even for this 1 year temporary setup the foul drain starts with an air admittance valve and the two toilets join this main pipe via branch couplings. Their foul drain does not lack natural gradient so I guess the air admittance valve is there to speed along the flow of a toilet flush.

Not sure where this thread is heading. Home generated KwH are precious and costly to store, surely the OP should drop in an LPG tank for space and hot water heating. His off grid electrical requirement would then be scaled to the worse case winters day demand for all led lighting, TV, central heating pumps and white appliances which should not be a scary number. Drawing from memory on my boating knowledge... £3k for a 5KVH diesel generator, wet acid batteries 1000 12v amp hours for say 4KwH of usable capacity = £1400 from Halfords then round that off with a nice deluxe Victron invertor/charger for £1500. I know such a scratch design needs improvement but my intention is to show this problem can be solved when the alternative is a £40K grid hook up cost.

I found a US YouTube video that did something similar and they also wrapped the bucket in permeable membrane to stop the sump from silting up. However that was for a permanent installation to drain a cellar.

I have a service trench at the same depth nearby the foundation trenches and this is dry so we are not talking about a rising winter water table. The water is surface runoff mostly from the exposed oversite. Not sure what you mean by "substructure" but I am talking about pooling water rising to 700mm below the yet to be reached dpc level. Most footing blockwork is heavy 19kg concrete blocks though the garage footings start with 1 course a thermolite like trenchblocks which I understand are not so resilient to freeze thaw cycles. Once my long term drainage is complete and the cavity fill in place the trench backfill will be the old excavated subsoil still onsite.

Your post got me thinking... although my situation is different to yours because my trenches have been part filled by foundation concrete to 600mm with footing blockwork on top. What I might do is dig a mud sump adjacent to the poured concrete at the low point of each water pool. If the mud sump is 100mm below the top of the current concrete pool base this should drain things near 100%. I want to get a system in place before the site experiences too many freeze/thaw cycles.

My foundations trenches have not been backfilled yet following the first two courses of footing blockwork and I am now seeing some standing water collecting after heavy rain. I am not sure what type of pump to buy to drain off the water. A dirty water pump sounds useful but a reviewer commented that they cannot suck up the final 50mm to 70mm of water. Puddle pumps are good for sucking up a pool of water down to a few mm however I am concerned such a design would gum up with the assorted debris in my trenches. In all cases the base of the collected water is my original foundation concrete which is 450mm below ground level and the deeper pools are, you guessed it, 50mm to 70mm. What type of water pump should I buy for this situation? I am not looking for an automated setup.

My local council charge £175 to register a new address but the department that does this admits this is not a mandatory process, they do however claim to have a monopoly tie-up with the Post Office PAF national database and said I cannot deal with the PAF people to side-step their fees. Council tax payment can happen without registering my newbuild address and right now my priority is getting a domestic refuse collection service at the new build site. Have others successfully avoided local council new build address registration?

Back in the 1980's I spent a few days in a luxury country villa that was off grid, there was no obvious compromise in lifestyle. One of the outbuildings contained a diesel generator and a large bank of wet acid 12 volt batteries. Technology has advanced since then.