So, what is the difference between Thai plumbing systems and your typical Western system?
This a good question, and one I am frequently asked by my clients.
I'll start with this question: When was the last time you saw a radiator in Thailand? or heard of someone getting underfloor heating installed? Never. It's simply too dam hot to ever have to worry about central heating. So, the fundamental difference is that plumbing systems in the tropics have absolutely no need to incorporate a central heating system. Pretty obvious really.
However, it doesn't end there. Don't confuse heating with domestic hot, drinking (potable) water. Although in the West, hot water generated by the boiler is always intrinsically linked to the central heating through both direct and indirect methods, the two are essentially very separate systems. i.e. one is for drinking and washing with (potable), the other is for heating cast iron radiators or under floor heating pipes and contains lots of nasty corrosion inhibiting chemicals making it downright poisonous. This is the reason that the two systems never mix under any circumstances and the reason for multiple strict buildings and environmental regulations.
In Thailand, as there is no central heating system to worry about there is no need (in theory) to dwell too much any of the above. However, water supplied by the government or privately (such as local wells and boreholes owned by the dwelling owner) is pretty much considered not safe to drink without treatment. I guess this gives Thailand a third type of water system (after heating and tap). Bottled drinking water or self purified tap water.
Hot water for showering and in some cases washing up dishes, is usually heated by an electric thermostatically controlled boiler. I have personally never seen a gas fired hot water boiler of the sort that we get in Europe, although I'd not be surprised to find these items in larger commercial environments where a requirement for large volumes of hot water is necessary.
So, number one difference is lack of central heating systems.
The Second difference is undoubtedly quality of materials and fittings. The Thai government does provide metered water to domestic and commercial property boundaries in most cases. The pressure at which this water arrives is hugely variable, is not regulated and consistent and is usually determined by the difference in elevation between the source and the dwelling (head pressure). Often the government water is then pumped from the property boundary into a ball-cock fed storage tank often located on the roof of the property. From here it is fed by gravity back down to the taps in the house. This gives a much lower water pressure than we are used to in the west, and means that the pipe work and associated taps, joins and other fittings can be of a much lower strength than their European and American equivalents. Combine the low pressure and lack of near boiling central heating water coursing through the system and you can pretty much get away with the cheap PVC 'blue' pipe work that you'll find in practically every house in Thailand if it is fitted properly and if it is not subjected to direct sunlight, as it is a tad fragile and deteriorates quickly under UV light.
The Third difference is lack of back-flow prevention which is a very big thing in the UK. Back-flow prevention devices are fitted 'in line' and prevent contaminated water from washing machines, showers, baths, WCs etc from the risk of reverse siphonic action where by the contaminated water flows back into the main tank or main government supply
As most tap water in Asia is not fit for human consumption anyway and is not intended for drinking untreated I guess this is the reason for lack of back-flow prevention regulation. However, a growing number of end users are now installing filtering devices and drinking tap water. Personally, I strongly recommend the fitting of back flow prevention devices in all cases.
Forth difference is lack of plumbing regulations. Basically you can do what the hell you want with regards to the design and installation of your plumbing system. All the more reason for getting a plumber who knows the risks of potential water supply contamination, pressure thresholds, and has a good understanding of general hydrodynamics
Fifth difference, and this is really an add on of the forth, I often see plumbing pipework that has been encased in concrete for cosmetic reasons. This is an absolute no-no. Should you get a leak or a blockage (dead lizard etc) then you'll have to knock holes in the wall to get to the source of the problem. Far better to spend a few extra Bht on some nice plastic sleeves or a bit of clever design to hide the blue pipe, but you must make sure that all pipework is accessible at all times and inside the house to protect from UV Light.
Sixth and final difference is lack of design and planning. Did you know that for every ninety degree bend you put in a pipe you're adding an extra two meters of flow resistance? Some of the crazy pipework I've seen (wrong pipe sizes, millions of joins, unnecessary bends etc) has literally been mind boggling. Far better to rip it all out and start again, except this time DESIGN and PLAN before assembling the system. I always work off a drawing, do my flow rates, get the right sized pipes for the job and make sure that the system is scalable and easy to maintain.
I once had an argument with a gentleman who came to fix guttering to my house in Suratthani. When he'd finished I noticed that the guttering actually ran up-hill away from the storage tank under the house, and the down pipe for the entire roof (approx 180 square meters) was two inches in diameter, which is just stupidly small.
When I told him to angle the guttering so that is would at least allow the water to flow into the down-pipe and perhaps even (heaven forbid) increase the down pipe to at least 6 inches diameter, he got got very upset and called me 'difficult', He said (in Thai to my wife who was watching the whole thing) 'Your husband doesn't understand, this is how I've always done it and nobody has complained before'. I speak Thai and understood him perfectly. I made him take it down and do it again. He took it down, got in his truck and drove off and never came back. I obviously had to do the job myself which ultimately meant that it worked properly.
Cultural differences are a lame old excuse when it comes down to confronting unacceptable levels of service. If you're not happy with something because it is wrong, then the chances are that the person delivering that service also knows it is wrong, unless of course they're a complete bloody idiot, in which case do you really want to be employing them in the first place?
Trying to pull the old 'this is Thailand (TIT), accept it' nonsense is the reason you need to employ people who appreciate that most farang very much understand that water does not flow uphill. Even in Thailand.
