Pipework and press fittings: DIY or installer?

Short answer: an experienced DIYer can install a simple water pipe with multilayer pipe and press fittings, for example an extra tap point or a pipe to an outdoor tap. But only if you have the right pressing tool, follow the manufacturer's method exactly and test the pipe before you conceal it. For the central heating system, a complete bathroom, pipes that disappear into a floor or wall, or anything involving gas, choose a certified installer. This guide explains where the line is and why.

Also available in Dutch: Leidingwerk en perskoppelingen: zelf doen of installateur?.

Why multilayer pipe and press fittings are so popular

Multilayer pipe is made of plastic with an aluminium core. It bends easily, keeps its shape and expands very little. Press fittings create a permanent joint without soldering or an open flame. That makes the system fast and clean, for installers and for people who like to do jobs themselves. Examples are the insulated Bonfix Alupers multilayer pipe or the bare Bonfix Alupers multilayer pipe 16 x 2 mm for short runs. Read more about the system in our blog on Bonfix Alupers multilayer pipe and press fittings and our blog on brass press fittings.

What can you do yourself?

How to work with press fittings

1. Plan the route and use a multifunction wall detector to find pipes and cables before you drill.
2. Shut off the water and drain the pipe.
3. Cut the pipe square with a pipe cutter for aluminium and copper. An angled or crushed pipe end will leak.
4. Calibrate and deburr the pipe following the manufacturer's instructions, so the O-rings are not damaged.
5. Push the pipe fully into the fitting and check through the inspection hole that it reaches the stop.
6. Press with the correct profile. Every system has its own press jaw; with the wrong profile the joint looks fine, but it is not.
7. Pressure-test the pipe before you conceal or insulate it.

Common fittings are an Bonfix press coupling, a Bonfix T-piece 16 x 16 x 16, a Bonfix press socket 16 x 16 for a straight joint, a Bonfix wall plate 16 x 1/2 for a tap point and an Bonfix end cap 16 to close off a pipe temporarily. To connect to existing copper pipe, use an adapter such as the Bonfix press to compression adapter 16 x 15. Tighten compression fittings and taps with a water pump pliers set and combination wrench set.

⚠️ Do not mix systems from different manufacturers. Pipe, fitting and press jaw must belong together. If in doubt, have an installer do it.

Where does it often go wrong?

• No suitable press jaw: without a matching pressing tool you cannot fit these fittings reliably. Only rent or borrow tools with the correct profile.
• Not deburred: a sharp edge cuts into the O-ring. The leak sometimes only appears after weeks.
• No pressure test: a pipe concealed without testing is a risk to your floor, ceiling or neighbours.
• Bends too tight: stay within the minimum bending radius, or the aluminium core will kink.
• No shut-off valve: fit a shut-off valve with every new tap point, so you can work safely later. More in our buying guide for shut-off valves and ball valves.

Working safely

Wear work gloves with nitrile coating against sharp pipe edges and a pair of safety goggles when drilling and sawing. Do not work on pipes near electrics unless you know exactly where the cables run, and always leave work on electrics and gas to a certified installer.

Why an installer is often the smartest choice

Calling in a professional is never unnecessary. An installer calculates which diameter is needed for sufficient flow, knows the regulations for drinking water installations, has the right pressing tools and carries out a pressure test with a calibrated gauge. And if there is damage, you know who is responsible.

👷 If you are in any doubt about your water pipes, and always for gas and central heating, call in a certified installer. A drinking water installation must meet the applicable regulations; an installer knows exactly what is needed. Installers who need larger quantities of multilayer pipe and fittings can contact Saniso for advice.

Frequently asked questions

Am I allowed to install a water pipe myself?

You may install a simple water pipe after the water meter yourself, as long as the installation meets the regulations. Work on the water meter and the connection before it is for the water company.

Can I fit press fittings without a pressing tool?

No. Press fittings need a press jaw with the correct profile. Without that tool the joint is not reliable.

Is multilayer pipe suitable for central heating?

Much multilayer pipe is suitable for drinking water and heating, but always check the specifications. Leave work on the central heating system to an installer.

How do I test whether my pipe leaks?

Put the pipe under pressure before you conceal it and check all joints. An installer does this with a pressure gauge over a fixed period.

Where can you find everything for this job?

At Saniso, the online store for DIYers and professionals, you will find tools, materials and personal protective equipment for your job.

• Browse our construction tools and our workwear and safety.
• Create a customer account and order easily.
• Working on a bigger project or want to hand over the job? Request a project quote.
• Book a showroom visit, at least 24 hours in advance.
• Not sure which material suits your job? Get in touch with us.

In doubt about the approach? Feel free to call in a professional.

Saniso – Build your home with Saniso.