The well has been dug for about a month but can we get the guy back to finish (don't answer that).

The problem has mostly been his inability to come up with a plan and a price that relate to each other - plans on the back on envelopes and costings that are either not itemised or bear no relation to the plan they are supposed to be for. At one point he expressed his labour charge for the whole job as a cost per square metre for the concrete pad to support the water tanks - where does that come from!

So finally I've done a plan of his suggestion which I attach below. The tank on the left has a carbon/manganese/sand filter built into it and the valve arrangements are supposed to allow for backwashing. Not pictured is a valve to prevent backflow which would be fitted near the top of the well.

What I'd appreciate is some advice about pipe sizes. His plan had everything in 1.5 inch pipe but my understanding is that I'm going to need a 2 inch pump to feed the 4 zone irrigation system (4x1 inch pipes) so my worry is that the drain on the tanks could exceed the input at times. What do you think?

I'm going to have a hut like Apetley pictured in response to my last post - the roller shutter is actually pretty cheap (about 3500 for a 3m opening, 2.3m high) and gives really good access.

Are you irrigating a garden or the local rice fields? Anyway... with your storage tanks, the size of the pipe doesn't really matter as long as you're not putting out more than you're putting in to the tanks over say 1 day's time.

Are you irrigating a garden or the local rice fields? Anyway... with your storage tanks, the size of the pipe doesn't really matter as long as you're not putting out more than you're putting in to the tanks over say 1 day's time.

The garden will be about 2 rai. When you account for the filter in the first tank it works out at around 5500 litres I think.

It Sounds like the borehole installer does not have a clue on doing the rest of the job.Your system looks like a western style system & most likely he has not ever done a system that is all automatic & perhaps doesn't understand how to do it.

You may be better off having him fire up (if he hasn't already)& let someone that is very confident & has a job or 2 you can look at to see he is not a bore hole cowboy & not a plumber.We had our well (not a bore hole put in & the contractor was on the fence on how & what to do to setup 4 & 1/2+ rai for irrigation & piping to the house. I wound up relieving him as it took a lot of math to figure out 18 zones with a 300 watt pump opposed to a 1& 1/2 hp that can deliver up to 9 bars. Mine clocks out at 4-5 bars max, so I had to use 1" pipes with shut offs on each portion. The drip irrigation was done in strip zones & was all dial it in trial & error. 1&1/2 inch pipes are the norm for a bore hole setup ....Although I have seen larger, but for a 1&1/2 hp setup this sounds right. Ours is all manual with the breakdown & failure rate in Thailand parts I only want to do the job once. I do all my own plumbing & so far have only had 1 pipe I forgot to glue in 7 years here.better than Somchai or Liam can do in a 1 month period.

While there are many great minds on the do it yourself forum the Farming forum is the real top notch mathematicians that do this for a living....cough cough HOBBY. Or have been into farming since they were a youngster.They gave me great insight into the distances I could make a run work on a zone. I learned on zone 2 to stick in an extra line(especially in the drip irrigation zones to add in a redundant extra unused line or 2 so I do not have to dig up jack shit if it fails . Just switch to the other line. On the 1" pipe & up I don't think it is that critical as PVC rarely fails.Ask your indepth questions in the farming forum & you will get some great answers. Not that any of the posters here are not very good, but the farmers been doing it forever!And believe me the men on that forum go into great detail & walk you through any thing you need to know.

Looks like a nice setup!

My only thoughts on the subject are, the 20mm of concrete slab and the 15mm for the pumps looks to be inadequate, for the two tanks when full will have a total weight of around 4tonne, or should the dreawing read 200mm and 150 mm ?

My only thoughts on the subject are, the 20mm of concrete slab and the 15mm for the pumps looks to be inadequate, for the two tanks when full will have a total weight of around 4tonne, or should the dreawing read 200mm and 150 mm ?

Oops! You're right of course. Wrong units, read cm.

Thanks Beardog. I have been getting my irrigation info from here which I found pretty useful. It doesn't seem very elaborate to me - four zones with a mix of drip and sprinklers but since the house isn't even started yet I'm only trying to make sure I don't lay any wrong foundations and have to go back and replace things. It may turn out to be manual when the time comes.

My only thoughts on the subject are, the 20mm of concrete slab and the 15mm for the pumps looks to be inadequate, for the two tanks when full will have a total weight of around 4tonne, or should the dreawing read 200mm and 150 mm ?

Oops! You're right of course. Wrong units, read cm.

Thanks Beardog. I have been getting my irrigation info from here which I found pretty useful. It doesn't seem very elaborate to me - four zones with a mix of drip and sprinklers but since the house isn't even started yet I'm only trying to make sure I don't lay any wrong foundations and have to go back and replace things. It may turn out to be manual when the time comes.

A definite concern!

nothing worse Than laying your irrigation before the house & having to change it all around later. We just demolished the old house to give us 3/4 of a rai more to grow a small orchard & now I get to relay new pipes.

That is a pretty comprehensive guide.I bookmarked it as well.

If you need some technical advise Maizefarmer-Slapout- Watersedge -Rice 555 -Gary A-Pondlife & the shout-outs can ggo on & on All have hands on & can write the book with all the things they seemed to have missed. Maizefarmer is an amazing man with a big heart that has an Godly like ability in the how to with all the angles of the dangle covered from the dynamics of a bore hole to how to deliver the water to the irrigation zones.If you need more in depth knowledge check the farming forum! and there is a bunch of posts that relate to irrigation & piping sizes for bore holes.

Faced with the pretty diagram and a spreadsheet, the guy finally itemised everything with us (saving several thousand baht along the way) and we agreed a price for all but the pump house which he hadn't seen before. I suspect he's going to come in too expensive so I'm on the look out for a couple of local guys to do it - I can't believe it's a very difficult job.

If you need some moral support to DIY - I have recently been through a lot of that (actually doing it myself and getting the locals to do things). Anyway.... There's a lot of locals that are pretty good at what they do - morter/concrete, plumbing, tile laying, painting, whatever. And there's some that are good at a lot of stuff. But if YOU are going to be the contractor (and I suggest most people with wherewhithall try it), YOU have to know what the plan is and be able to lay it out. (probably with the wifey's help). Then, you have to keep on top of things every F minute to make sure that's what actually happens. Like I say, I've been there done that - and it does work out OK but you HAVE to stay on top of things. You might be surprised to see what you can save hiring "day labor" versus a contractor or whatever per "salong met".

Cheers