Plumbers with differences of opinion!

[txp112]

I have just purchased a property and im having the whole plumbing and central heating done. The property has 2 bathrooms one on the ground floor and one on the first. It also has an onsuite in the loft. A problem i had in the property i moved from was that, when the sink taps were on downstairs you would get poor flow in the bathroom upstairs etc. Furthermore the plumbing was, i believe so badly botched that in the bathroom with the cold water supply (15mm pipe) branched of to the sink, then a branch came of this to the shower, with a branch coming of this to the toilet. This would cause the the shower to die if you turned the tap on or flushed the toilet.

I asked the plumber if this could be overcome in the new property by running a 22mm pipe for the cold supply to the loft and branching 15mm pipes directly of this for the shower and toilet etc. One of the plumbers said that this could be done, however the other said only 15mm could be taken to the loft for the cold water. The mains water pressure for the property is good. At this point it should be evident i am a complete noob to plumbing. I would be grateful if somebody could tell how the pipe branching should occur in this property, and if theres any way i can prevent the problems i have described from occurring in the new property. thanks

 

[Paul Barker]

The crux of the matter is quality of your incoming supply. However your plan to use a 22mm trunk route would ensure best performance, if using plastic the price diference is insignificant compared to the benefits.

In a situation of poor supply, there will be a small benefit, but you need all the help you can get and it's not costly at this stage.

 

[Nige F]

modern wc`s with "quiet ballvalves" need mains water to fill @ a decent rate...in my opinion

 

[BoxBasher]

One thing that always puzzles me... why would you flush the toilet or use the sink whilst in the shower?

You will experience a "pressure drop" in the shower if any tap is opened in the house, but if your incoming supply is adequate then the drop will usually be insignificant.

All plumbing systems are different, just because you had a particular problem in your old house doesn't mean that it will manifest itself in your new house. You will experience problems/fluctuations if trying to use 3 bathrooms simultaneously regardless of mains pressure, it is the flow that should be of more concern. Does the problem happen in the new house??

If your incoming mains supply is around 15 LPM and you are trying to draw water from 3 different sources then it is potentially split three ways to 5LPM (not quite that simple/equal split), not really a great flow level, sometimes incoming flow is considerably less than this.

 

[bathjobby]

To prevent the shower being affected by other usage it should have its own 15mm supply from the cold water storage tank and its own 15mm hot water supply from the hot water storage tank and it should be the first thing fed from the hot water tank (assuming this is your set up), you can use a surrey flange for the hot if not already done.

 

[Agile]

If the mains supply is very good, say 45 li/min, then you can feed every outlet from a manifold at the inlet. Thats often good for flats on one level.

However, in a taller house it needs a competent plumber to give good advice.

I sus that you have got a cheap plumber. They are not usually very clued up!

If you wanted a good plumber then he would probably be a member of the Institute. I dont expect yours is!

Tony

 

[jonathan steel]

I agree a 22mm trunk route would be your best option unless you want to re-do the entire plumbing.

go with plastic and see if it improves. let us know the results

Jonathan

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[txp112]

thanks to all for their advice