Rug underlays divide into two broad types that solve overlapping but different problems. Buying the wrong one produces mild disappointment rather than failure, which is why the distinction is worth understanding first.

Grippers

Thin open-mesh material, usually with a tacky coating, laid between rug and floor. Its single job is friction: it stops the rug sliding.

It adds essentially no thickness, costs little, and works well on hard floors. It does nothing for comfort, does not protect the floor from wear, and provides no sound absorption.

Cushioned Pads

Thicker construction, typically felt bonded to a grip layer, in the region of three to six millimetres. They grip and they add substance.

The rug feels noticeably thicker underfoot, sound is absorbed rather than reflected, the rug’s own fibres are protected from being crushed against a hard floor, and the floor beneath is protected from grit ground in by footfall.

Ranges offering both a thin gripper line and a cushioned felt line in matching sizes, of the kind catalogued at https://veken.us.com/, make the choice a matter of what you want rather than what fits.

Which to Choose

• Thin rug on hard floor, purely to stop sliding: gripper
• Living room rug you walk on daily: cushioned pad
• Under a dining table, where chairs move: thin, since thickness catches chair legs
• Flat or antique rug where thickness would look wrong: gripper
• Flat over a hard floor in an upstairs flat: cushioned, for the acoustics

The Longevity Argument

A cushioned pad extends a rug’s life measurably. Without one, footfall grinds the rug’s backing directly against a hard floor and grit works into the fibres from beneath.

For an expensive rug this is the strongest argument for the thicker option, since the pad costs a fraction of the rug and noticeably slows its wear.

Thickness Trade-Offs

More cushion is not automatically better. A thick pad raises the rug enough to catch doors that clear it currently, creates a more pronounced edge to trip on, and makes chairs harder to move.

Doorways are the practical check. Measuring the clearance under a door before adding several millimetres prevents an irritating discovery.

Rugs on Carpet

Neither standard type is designed for this. A gripper on carpet grips the carpet pile rather than the floor and moves with it.

Specific carpet-to-carpet products exist and work differently, using texture rather than tackiness. Using a hard-floor pad on carpet is the most common reason people conclude that pads do not work.

Floor Finish Compatibility

Some older or cheaper pads contain plasticisers that react with floor finishes, leaving a discoloured shadow that is permanent.

This is worth checking before laying anything on a good wooden floor, and lifting a corner after a few weeks to inspect is a sensible precaution regardless.