It's all to do with water pressure. PVC joints are glued and the joints will not stand up to water pressure. Plastics pipes (not PVC) can be used provided that the correct joints are used.

In Sri Lanka outside of big cities the norm is to pump the water up to a water tank, from where it enters the house by gravity. I would presume there wouldn't be enough water pressure to create a problem.

By the way what is the beef about using PVC pipes inside the house?

It's all to do with water pressure. PVC joints are glued and the joints will not stand up to water pressure. Plastics pipes (not PVC) can be used provided that the correct joints are used.

In my house I used the 13.5 PVC pipes for the cold water and copper pipes for the hot water. All pipes were pressure tested for 24 hours with 10 bars to ensure there were no leaks. Also I see no problem using the high rated PVC pipes but of course the glued joint will have to be properly pressure tested.

By the way what is the beef about using PVC pipes inside the house?

It's all to do with water pressure. PVC joints are glued and the joints will not stand up to water pressure. Plastics pipes (not PVC) can be used provided that the correct joints are used.

In my house I used the 13.5 PVC pipes for the cold water and copper pipes for the hot water. All pipes were pressure tested for 24 hours with 10 bars to ensure there were no leaks. Also I see no problem using the high rated PVC pipes but of course the glued joint will have to be properly pressure tested.

PVC 13,5 normally blows up at 4 bars. Its cheap stuff suited for sprinkler and outside walls installation. Illegal to build in in developed countries like China and Malaysia.

For a normal size villa with 3-4 bath, PPR pipes is just another 20-40 k baht. Good for 8 bar for 50 years cold water or 30 years at 6 bar hotwater 80C. Longer lifetime than copper and more easy to install.

Run 3-4 bar pressure and pipes live longer than me