First Fix Plumbing: Pipes, Connections, and the Mistakes to Avoid

Your plumber will probably be on site for one or two days. The pipework itself is the easy bit. What's hard is making sure the right pipes end up in the right walls, that nobody skips the pressure test, and that the Gas Safe certificate actually arrives. On one project, that certificate took 14 months. Building control couldn't sign off the extension until it did.

First fix plumbing covers everything that gets buried: hot and cold water supply pipes running from the mains and boiler to every tap and appliance, waste pipes carrying dirty water from sinks and dishwashers to the soil stack or drain, and gas pipework from the meter to the boiler (and to the hob, if you're running gas). Once the plasterer and screeder have finished, this pipework is sealed inside your walls and floors for the life of the building. Getting it wrong means tearing plaster off walls to fix it.