COMPARISON
PP-R versus multilayer: where each one wins
Updated: 2026-08-19
Short version: for pipe buried in walls or screed, PP-R is cheaper and more reliable — provided you weld it carefully. Multilayer wins when there's no room to weld, you need a bend held in place, or the joint has to stay accessible. Below, point by point, is exactly where they differ.
Point by point
| Criterion | PP-R | Multilayer |
|---|---|---|
| Pipe and fitting cost | pipe about the same, fittings several times cheaper | dearer because of the fittings, press ones especially |
| Tooling | welding iron, cheapest way in | press jaws, or compression fittings by spanner |
| Learning curve | weld in an hour, but mistakes are invisible | compression instantly, press needs skill and a calibrator |
| Bends | fittings only | bends by hand and holds the shape |
| Buried in screed or wall | yes, the joint is monolithic | press fittings only — never compression |
| Repairing a section | cut out and weld a piece in | undo a compression fitting, or cut out a press one |
| Thermal expansion | significant — needs reinforcement and compensation | 5–6 times less than unreinforced PP-R; long straight runs still need compensation |
| Weak spot | an overheated joint narrows the bore invisibly | an uncalibrated cut slices the O-ring |
Pipe materialsAll six materials side by side: joining, temperature, price, where each belongs.
Pipe diametersSize ranges of every system, outer vs inner diameter, which pipe pairs with which thread.
Choose PP-R when
- The pipe goes inside walls or under screed and nobody will see the joint again: a welded seam is monolithic and doesn't rely on a rubber ring.
- Risers and larger diameters — the price gap at 32–50 mm becomes real money.
- You're doing your own place and aren't in a rush: the iron is cheap and quality comes down to care.
Choose multilayer when
- The run is visible and you want clean bends instead of a dozen elbows.
- Tight spots a welding iron physically can't reach: behind a bath, inside a cabinet, tight to a wall.
- Quick repairs and tie-ins: a compression fitting goes together with a spanner, no power needed.
- Underfloor heating in screed — though PEX is usually cheaper and more flexible there.
Myths that get in the way
“Multilayer is always safer — it has aluminium in it.”
The aluminium holds shape and kills expansion, but in press and compression fittings the seal comes from a rubber ring. A badly calibrated cut leaks regardless of the metal.
“You can weld PP-R roughly, the seam holds anyway.”
Overheating pushes a bead into the bore: the joint looks perfect outside while your pressure drops. It's the most common hidden mistake there is.
Twisting the fitting after pushing it home, “to line it up”.
Rotating tears the melt that has already gripped, and the joint stays unsealed while looking perfect. Push it together, hold it still until it cools, and set the angle before you weld.
“PP-R isn't for heating.”
Reinforced PN20/PN25 is. It's the unreinforced pipe that sags in waves on hot water — that's the one to avoid.
Common questions
Which is cheaper, PP-R or multilayer?
PP-R: the pipe costs about the same, but the fittings are several times cheaper, and a welding iron costs a fraction of what press jaws do. Multilayer is not bought for price — it is bought because it bends in place and goes together with a spanner, no power needed.
Which of them can be buried in a wall?
PP-R, yes — the welded joint is monolithic. Multilayer only on press fittings. Compression joints must never be concealed: they are designed to be re-tightened and have to stay accessible.
Is multilayer really more reliable because of the aluminium?
The aluminium holds the shape and kills thermal expansion, but in press and compression fittings the seal comes from a rubber O-ring. An uncalibrated cut edge slices that ring, and the joint weeps whether or not there is metal in the pipe wall.
Related pages
Check it in the builder, not at the store
Lay your assembly out in easy-pipe — parts only connect when diameter and thread genuinely match.