Rods and pipes
Rods and pipes covers aluminium rectangular tube, copper pipe, PE pipe, pipe trace heating, PVC pipe and underground drainage pipe. Each comparison says what that product is for, and which checks still apply when the listings change.
Once you have the product type, the comparison is where the current listings live. Shelf prices and makers stay there.
Rods and pipes

Aluminium rectangular tube
Short mill-finish bars
Compare five aluminium rectangular tubes on amazon.co.uk, from about £11.00 to £21.59. See section, wall, stated 6063-T6, and the top pick for a light frame under 1 m.
Comparison guides

Copper pipe
15 mm stick, craft and brake kits
Compare ten copper pipe listings on amazon.co.uk, from about £5.19 to £21.99. A 15 mm metre, short craft tubes, and coated brake kits. No plumbing title states BS EN 1057.
Comparison guides

PE pipe
Garden coil and fridge tube
Compare seven PE pipe listings on amazon.co.uk, from about £7.99 to £96.95. Garden coil, fridge tube, and irrigation. None is a checked blue service coil.
Comparison guides

Pipe trace heating
Frost cables for short pipes
Compare ten pipe trace heating cables on amazon.co.uk, from £10.39 to £66.49. The top pick states 230 V for a heated run of about 3 m. No cable was laboratory tested.
Comparison guides

PVC pipe
Waste, duct and clear tube
Compare nine PVC pipes on amazon.co.uk, from about £4.99 to £11.69. Waste, ventilation duct, and clear tube. None of the nine states a British Standard.
Comparison guides

Underground drainage pipe
Kits, not a BS EN 1401 pipe
Compare three underground drainage listings on amazon.co.uk, from £12.99 to £20.99. A rainwater kit, a downpipe extender, and a solvent-weld metre. None names BS EN 1401.
Comparison guides
Rods and pipes guides
View all articles →Guides on what a short aluminium box section costs, when an outside condensate pipe still freezes, and which copper size a kitchen tap needs.

Aluminium box section price per metre in the UK
You have a 1 m aluminium rectangle in the basket at £13.15, and a shop page for the same 30 × 15 × 1.3 mm 6063-T6 section at £2.98 inc VAT per metre.

Condensate pipe trace heating: when the run still freezes
The heating stops on the first hard frost, the radiators stay cold, and the plastic pipe that leaves the boiler through the outside wall is solid with

Copper pipe size for kitchen tap: match the supply
The old mixer is on the drainer, both isolating valves are shut, and the copper under the sink does not look like the figure on the new box. Copper pi