The main pipe fittings types are PVC (rigid pressure and drainage), poly (flexible cold water and irrigation), copper (hot water and gas), and push-fit (tool-free connections). PVC and poly are cheapest and easiest for DIY, copper needs soldering or crimping, and push-fit is fastest for quick repairs and awkward spots.
Why does the pipe fitting material matter?
A fitting is only as good as its match to the pipe and the pressure it carries. Use the wrong material and you get leaks, failed joints, or a connection that won't pass an inspection. Getting it right first time saves you draining the system twice.
Each material has a job it does best. PVC and poly dominate cold water and stormwater, copper handles heat and gas, and push-fit bridges different materials in a hurry. Browse the full plumbing range to see how the four families line up side by side.
Before you buy, confirm three things: the pipe outer diameter, whether the line is pressure or drainage, and if it carries hot water or gas. Those three answers point you straight to the right fitting.
PVC fittings: the DIY drainage and cold-water workhorse
PVC (polyvinyl chloride) is rigid, cheap and joined with solvent cement. It's the default for stormwater, sewer, and pressure cold-water lines around the average home. Cuts with a hacksaw and glues in seconds.
Pressure PVC is usually marked with a class or pressure rating and used for supply, while DWV (drain-waste-vent) PVC handles gravity drainage. Never swap the two, as drainage fittings aren't built to hold pressure. Match the socket size to your pipe's outer diameter, not the internal bore.
Where PVC shines
Downpipes, garden drainage, gully traps and cold-water risers are all natural PVC territory. It's the friendliest system for a first-timer because there's no heat, no crimping and no special tool beyond a saw and a can of cement.
Poly fittings: flexible cold water and irrigation
Poly (polyethylene) pipe is flexible black tubing joined with compression or barbed fittings. It's the go-to for rural water lines, garden irrigation, and long cold-water runs where a flexible coil beats rigid lengths. No glue, no heat, just tighten or push on.
Compression fittings grip the pipe with a nut and internal ring, so they're reusable and handle mains pressure well. Barbed fittings suit low-pressure irrigation and are held with a clamp. Poly comes in metric and older imperial sizes, so measure carefully before ordering.
If you're plumbing an outdoor tap or a rainwater feed, poly pairs well with the broader plumbing and electrical accessories you'll need for a tidy, weatherproof install.
Copper fittings: hot water and gas duty
Copper handles heat, pressure and gas that plastics can't, which is why it still rules hot-water lines and gas services. Fittings are joined by soldering (sweating) or by crimp/press systems that need a proper tool. It's durable and long-lived but the least beginner-friendly.
Gas and hot-water work is regulated in Australia. Most gas connections and many hot-water alterations must be done by a licensed plumber or gasfitter, not a DIYer. Copper is worth understanding, but know where the legal line sits before you pick up a torch.
Soldered vs press fittings
Soldered joints are cheap and permanent but need flame, flux and skill. Press fittings crimp onto the pipe with a rubber O-ring seal and are far faster, though the crimping tool is a real investment. For a one-off repair, neither is usually the DIY choice.
Push-fit fittings: the fast, tool-free option
Push-fit fittings snap onto the pipe by hand and seal with an internal O-ring and grip ring. They join copper, PEX and poly interchangeably, which makes them brilliant for repairs, retrofits and tight cupboards where a torch won't fit. Many types can be released and reused.
They cost more per fitting than glue-on PVC, but you save on tools and time. Always push the pipe fully home to the depth line, or the seal won't seat. A deburred, square-cut pipe end is non-negotiable for a reliable push-fit joint.
Which pipe fitting suits which job?
Match the fitting to the job rather than defaulting to whatever's in the shed. The table below sums up the four families at a glance so you can shortlist before you buy.
| Fitting type | Best for | Join method | DIY difficulty | Reusable? |
|---|---|---|---|---|
| PVC | Drainage, stormwater, cold-water pressure | Solvent cement | Easy | No |
| Poly | Irrigation, rural and outdoor cold water | Compression or barb | Easy | Compression: yes |
| Copper | Hot water, gas, high heat | Solder or press/crimp | Hard | No |
| Push-fit | Repairs, retrofits, tight spaces | Push by hand | Very easy | Often yes |
As a rule of thumb: cold water and drainage lean PVC or poly, anything hot or gas leans copper, and any quick fix leans push-fit. When two options both work, pick the one you have the tools and confidence for.
Fittings that connect to fixtures and filters
Plenty of jobs aren't a straight pipe run but a connection to a tap, filter or appliance. Under-sink water filters like the Aquaport 600L replacement filter cartridge tie into your cold line and rely on the right adaptor to seal cleanly. Getting that fitting right stops slow drips behind the cupboard.
Tap-mounted systems such as the BRITA On Tap Pro V-MF water filter refill screw straight onto a standard spout, so no plumbing fittings are needed at all. Knowing which jobs need a proper connection and which just clip on saves you buying parts you'll never use.
Care and usage tips for a leak-free join
Good technique matters more than expensive parts. A rushed joint in any material is the number one cause of DIY leaks, so slow down at the connection.
- Cut square and deburr every pipe end so O-rings and cement seat evenly.
- Match the size to the outer diameter, and double-check metric versus imperial on older pipe.
- Use the right cement for the pipe type and let it cure fully before turning the water on.
- Push or tighten fully home to the depth mark on push-fit and compression joints.
- Support long runs with clips so weight and movement don't stress the fittings.
Keep a small kit of common adaptors, thread tape and spare O-rings on hand. Most weekend leaks come down to one missing 15mm fitting, and a stocked drawer turns a two-trip job into one.
Frequently asked questions
How do I know what size pipe fitting to buy?
Measure the pipe's outer diameter, not the internal bore, and match it to the fitting size. Common household sizes are 15mm and 20mm for copper and 13mm to 25mm for poly. If you're unsure, take a short offcut of the old pipe to the store to compare directly against fittings.
Can I mix copper and plastic pipe fittings?
Yes, push-fit fittings are designed to join copper, PEX and poly interchangeably, which makes them ideal for connecting old and new sections. Compression adaptors also bridge materials. Just avoid direct copper-to-galvanised contact without a proper transition fitting, as it accelerates corrosion at the joint.
Do push-fit fittings meet Australian plumbing standards?
Reputable push-fit fittings sold for potable water carry a WaterMark certification, which means they meet the required Australian standard. Always check for the WaterMark logo before buying, and follow the fitting's depth and pipe-prep instructions so the certified performance actually holds in your install.
Which pipe fitting is easiest for a beginner?
Push-fit is the most beginner-friendly because it needs no glue, heat or tools, just a clean square cut and a firm push. PVC is a close second for drainage work since it only needs a saw and solvent cement. Leave copper soldering and any gas work to experienced hands or a licensed plumber.
