# Domestic plumbing done properly

*The water regulations, the three joints, and the hard legal line at gas.*

## Production summary

- Modules to record: 2
- Total script: 1239 words, about 8 minutes of finished audio
- Voices: Amara (host) and Nadia (practice educator)
- Level: Beginner to competent DIY, and a grounding before trade training

## Accreditation wording that must appear in the description

- **The CPD Certification Service** (planned): Application scheduled.

> Do not upgrade any of these words in a description or a thumbnail. Aligned is not accredited, and planned is not approved.


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## The water regulations, and why backflow is the thing that matters

**Runtime** about 4 minutes. **Words** 578. **Starts at** 00:00 in the full course recording.

### Learning outcomes to state on camera

- State what the Water Supply (Water Fittings) Regulations 1999 require of you
- Classify a risk by fluid category and choose the right protection
- Explain air gaps, double check valves and where each belongs
- Know which work must be notified to the water undertaker

### Script


`[CUE 1]` *Five fluid categories as a rising bar, with an everyday example on each.*

**AMARA**  [00:00]
Do I need to be registered to do plumbing in my own house?

**NADIA**  [00:05]
For most domestic water plumbing, no. And that surprises people, because everybody assumes plumbing is like gas.

**AMARA**  [00:12]
So it is unregulated?

**NADIA**  [00:13]
Not remotely. There is no registration requirement but there absolutely is law. The Water Supply Water Fittings Regulations 1999, and the byelaws in Scotland, apply to anybody who installs or alters a water fitting. Breach them and it is a criminal offence with a fine attached.

**AMARA**  [00:32]
What are they actually for?


`[CUE 2]` *Air gap versus double check valve, with the valve failing and the gap not.*

**NADIA**  [00:34]
One thing above all. Stopping contaminated water getting back into the drinking supply. Everything else in them is secondary.

**AMARA**  [00:41]
Backflow.

**NADIA**  [00:42]
Backflow. And once you understand that it is the point, the whole rulebook stops feeling arbitrary.

**AMARA**  [00:48]
Then teach me the framework.

**NADIA**  [00:50]
Five fluid categories. One is wholesome water as supplied. Two has changed in taste, smell or appearance but is not a health risk, so warmed water. Three is a slight hazard, a heating system with no additives, a domestic washing machine.


`[CUE 3]` *Outside tap and hose in a water butt, with the backflow path highlighted in red.*

**AMARA**  [01:06]
And the serious ones?

**NADIA**  [01:08]
Four is a significant hazard: inhibitor, antifreeze, pesticide. Five is the serious one, and it means human or animal waste or pathogens. A WC. A bidet. A trough. A sink you have been cleaning in.

**AMARA**  [01:22]
How does the protection change?

**NADIA**  [01:24]
It rises with the category, and at category 5 you need the one protection that cannot fail mechanically. An air gap. A physical vertical gap between the outlet and the highest the dirty water could ever reach.

**AMARA**  [01:39]
Why not just fit a good valve?


`[CUE 4]` *Street main bursting and the pressure dropping, siphoning the system backwards.*

**NADIA**  [01:41]
Because a valve is a mechanism, and mechanisms fail. Grit, scale, age. An air gap is a piece of empty space and it has never failed in the history of plumbing.

**AMARA**  [01:54]
Give me the everyday example, because this still feels theoretical.

**NADIA**  [01:58]
Your outside tap. Hose screwed on, other end lying in a water butt, or a pond, or a bucket you have been washing the car in.

**AMARA**  [02:08]
That is most houses in Britain.

**NADIA**  [02:11]
It is. And that is a direct path from category 5 water into the drinking main, waiting for a pressure drop.


`[CUE 5]` *Notifiable work list: bidet, irrigation, large pond, large bath.*

**AMARA**  [02:19]
How would the water go backwards though? It comes out under pressure.

**NADIA**  [02:24]
Until it does not. A main bursts down the street, the pressure drops, and the system siphons. That is not a hypothetical, it is exactly how contamination incidents happen and why undertakers care so much about it.

**AMARA**  [02:39]
So what does that outside tap need?

**NADIA**  [02:42]
A double check valve, which is two check valves in series and protects to category 3, plus the discipline not to leave the hose end submerged. About eight pounds of fitting, and it is the most common breach in the country.

**AMARA**  [02:58]
Is there anything I have to tell the water company about before I do it?


`[CUE 6]` *Isolating valve fitted at an appliance, with the whole house staying live.*

**NADIA**  [03:04]
Yes, and people miss this. Certain work must be notified in advance and they can refuse consent. A bidet with a flexible hose. Any garden irrigation system. A pond or pool over ten thousand litres. A bath over two hundred and thirty litres.

**AMARA**  [03:21]
A big bath needs permission?

**NADIA**  [03:23]
It does, because of the draw on the main. It catches out a lot of bathroom installers doing a high end job.

**AMARA**  [03:32]
Last thing. Fittings.

**NADIA**  [03:33]
Use ones approved for potable water, so WRAS approval or another recognised UK scheme. And fit an isolating valve at every appliance, because the next person to repair it will otherwise be draining the whole house, and quite often that next person is you.

### Sources for the on screen credit

- Water Supply (Water Fittings) Regulations 1999, legislation.gov.uk
- Water Fittings Regulations guide and fluid categories, WRAS
- Water Byelaws 2014, Scottish Water
- Backflow prevention guidance, Chartered Institute of Plumbing and Heating Engineering

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## Joints, leaks and the repairs worth doing yourself

**Runtime** about 4 minutes. **Words** 661. **Starts at** 03:51 in the full course recording.

### Learning outcomes to state on camera

- Choose between soldered, compression and push fit joints and justify it
- Make each joint type properly, and know what makes each one fail
- Diagnose a leak by where and when it appears
- Recognise the work that must never be attempted without registration

### Script


`[CUE 1]` *Gas Safe boundary card: what is legal, what is a criminal offence.*

**AMARA**  [03:51]
Before we start on joints, what is the hard line?

**NADIA**  [03:55]
Gas. Under the Gas Safety Installation and Use Regulations 1998, only a Gas Safe registered engineer may work on gas fittings and appliances.

**AMARA**  [04:04]
Not a competent amateur.

**NADIA**  [04:06]
Not a competent amateur, not a confident plumber, not you. That includes the gas supply to a boiler, gas cookers, gas fires and the pipework serving them. It is a criminal offence, it voids buildings insurance, and carbon monoxide from bad gas work kills people every single winter.

**AMARA**  [04:25]
Is there anything I may do?


`[CUE 2]` *Three joint types in cross section with the failure mode animated on each.*

**NADIA**  [04:27]
Turn it off in an emergency, and work on the water side of a wet system. That is the whole boundary and it does not move.

**AMARA**  [04:38]
And if I smell gas?

**NADIA**  [04:40]
Do not touch any electrical switch, not even to turn a light off. Open windows, turn off at the meter if you can safely reach it, get out, and ring 0800 111 999 from outside.

**AMARA**  [04:54]
Right. Joints. There are three kinds and I have never known which to use.

**NADIA**  [04:59]
Match the joint to where it is going. Soldered capillary joints are the strongest, cheapest and neatest, so they belong anywhere the joint is going to be forgotten about. Inside a wall. Under a floor.


`[CUE 3]` *Capillary action drawing solder into a heated fitting.*

**AMARA**  [05:13]
What makes a solder joint fail?

**NADIA**  [05:16]
Three things, and it is always one of them. The pipe was not clean. There was water in the line so it never got hot enough. Or somebody nudged it while it was cooling.

**AMARA**  [05:29]
How do I get it right?

**NADIA**  [05:32]
Clean pipe and fitting to bright copper, flux both, and then heat the fitting, not the solder. Let capillary action draw it in. If you are melting solder with the flame you are doing it wrong.

**AMARA**  [05:46]
Compression?


`[CUE 4]` *Crushed olive from over tightening beside a correctly seated one.*

**NADIA**  [05:46]
Demountable, no flame, so it is right where a blowtorch is dangerous or where you might need to take it apart. And it is ruined by exactly one thing: over tightening.

**AMARA**  [05:59]
Everyone over tightens.

**NADIA**  [06:00]
Everyone does, because it feels like security. You crush the olive out of shape and it will never seal again. Tighten until it bites and then usually not more than a turn. Then test it rather than heaving on it for insurance.

**AMARA**  [06:17]
And push fit? Real plumbers seem sniffy about it.

**NADIA**  [06:20]
Some are, and they are wrong. It is fast, it tolerates a damp pipe, and for a repair under a floor on a Sunday it is excellent. It fails for three reasons and all three are avoidable.


`[CUE 5]` *Pencil insertion mark disappearing as push fit pipe seats fully.*

**AMARA**  [06:35]
Which are?

**NADIA**  [06:36]
The cut was not square. The pipe was not pushed fully home. Or somebody left the insert out of plastic pipe. So: deburr it, mark the insertion depth on the pipe with a pencil, and push until your mark disappears.

**AMARA**  [06:52]
Let us talk about finding leaks. Water appears on a ceiling and I have no idea where it came from.

**NADIA**  [07:00]
Then read the timing first, before you open anything. Constant drip whatever you do means the supply side, because that is under pressure all the time. Only when a tap runs or an appliance drains means the waste side.

**AMARA**  [07:16]
And only when the heating is on?


`[CUE 6]` *Water tracking along a joist and dropping away from the source.*

**NADIA**  [07:18]
A heating circuit joint opening up as it expands. That one drives people mad in summer because it does not leak at all.

**AMARA**  [07:28]
What about the ceiling stain?

**NADIA**  [07:30]
Almost never directly under the source. Water tracks along a joist and drops at the first low point. So look higher and to one side, and do not start cutting the ceiling out where the stain is.

**AMARA**  [07:44]
Last thing. What is worth learning to do myself?

**NADIA**  [07:48]
Tap washers and ceramic cartridges, traps, toilet fill and flush valves, isolating valves, flexible connectors and blockages. That is the very large majority of every callout a domestic plumber attends.

**AMARA**  [08:00]
Any habit that helps?

**NADIA**  [08:02]
Three. Fit an isolating valve while you are in there. Photograph it before you dismantle anything. And lay the parts out in the order they came off. The plumber's bill is rarely the part.

### Sources for the on screen credit

- Gas Safety (Installation and Use) Regulations 1998, legislation.gov.uk
- Gas Safe Register: the law on gas work, Gas Safe Register
- Copper tube jointing good practice, Copper Development Association
- Domestic plumbing standards, Chartered Institute of Plumbing and Heating Engineering

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