Your professional opinion please.

[Nat]

Hi all,

Not that long ago I did a job for a builder who I do a bit of work for. The job was a commercial premises in the middle of Brighton. Not sure what the premises used to be but it was a refurb to make the place into a kind of treatment rooms/spa type business. The shop is on 4 floors which had an existing half inch lead main into the building then sporadic 15 mm copper and half inch lead here and there. The plans proposed 6 basins, a kitchen sink, a toilet and 2 showers (which I was told could be used simultaneously). I advised the customer that a 22mm main would need to be run throughout the building from basement through to first and second floor, then 15mm to feed 2 basins at the top of the building. He asked why and I advised that you would get pressure drop off if someone was having a shower and someone else jumped in the other shower/flushed the toilet/used the basin (baring in mind this is a commercial premises).

I also told him that he would need to get the water supplier to upgrade the main from the stopcock in the road into the building where I would pick up on it (only about 1200mm of pipe). So I completed the rest of the installation in 22mm branching off in 15mm to feed the appliances.

When the install is complete the customer (not the builder) comes back to me and says that the water supplier wants a ridiculous amount of money to replace the 1200mm from the stopcock in the pavement outside into the building so I say 'well let's see how it works as is'. We test it and the pressure and the flow rates are good and there is no drop off. He asks me why this is considering there is still a small amount of 15mm coming into the building and I tell him it is because 95% of the rest of the pipework is in 22mm. I am no professor of fluid dynamics but I know it's all about the volume of the pipework and that there is less frictional resistance from the larger pipe bore. I know even from my own house which is all piped up in 15mm when I am having a shower and the wife opens the kitchen tap there is a considerable loss of pressure.

Anyway, to get to the point, he know thinks I have convinced him to have unnecessary work done. I have already been paid by the builder but he is holding money back from them and this is damaging my reputation.

In this situation would you have done the same? Please help I need an answer from as many people as possible.

Thanks!

 

[Koogatubac]

Jesus that was lengthy lol

 

[Scott_D]

He is holding money back from the builder for work he was going to pay the water company to do?

 

[REDSAW]

''this is the right way'' but as it works satisfactory as is....pay up!.

 

[hammers4spanner]

In my opinion you were covering your urse by advising an upgrade in pipe size , always loads of variables in plumbing but either way gimme your money

 

[plumber0808]

You covered your bum by doing the work that you have done.
if you left it in 15mm and it didn't work they would come back at you exactly the same as they are now by saying the work you have done doesn't work properly.
The work is complete and working correctly as you stated.

They are more than likely haggling with the builder at the end of the job which happens quite a lot to get them to knock some money off the bill.
There grasping at straws as your part is working as it should, stick to your guns.

 

[jase158]

I would speak to them and say you were just covering your bum, liase with builder and tell him what you are doing.

 

[secret squirrel]

The problem is between the builder and customer, your right, stick to your guns, it works and works well, don't see the issue. Sounds like a good job. The customer has saved himself money by not having the mains upgraded.

 

[Nat]

Thanks for your replies but I think I have probably clouded the issue a bit here with unnecessary information!

What I should have asked simply is if a customer of yours was proposing to fit 6 basins, a sink, a toilet and 2 showers in a commercial premises would you advise them to run 22mm or 15mm?

What would YOU say?

 

[mfgs]

22mm without a doubt

 

[plumber0808]

22mm.

 

[Scott_D]

If you want to prove a point, you could find out the flow rate of all outlets/max flow rate of 15mm and 22mm pipe and pass the info onto to the customer.

 

[PlumbBobBob]

22mm as well

 

[markfxy]

the resistance is less with a larger pipe and as you have two showers to serve you've done the right thing. I'm in the Brighton area give me the address and I'll go carp on his doorstep:smilewinkgrin: