If free weights are involved, buy 20mm. If the room is for cardio machines, bodyweight work and light dumbbells, 15mm does the job and saves you a little height and money.
That is the rule we give every customer who asks, and it is why the 20mm PRO is the tile most of the 55,000 Sprung home gyms are built on. Five millimetres does not sound like much. Under a dropped dumbbell it is the difference between a thud and a crack.
The short version
| 15mm | 20mm | |
|---|---|---|
| Best for | Cardio rooms, stretching, yoga, light dumbbells, upstairs rooms | Home gyms with a rack, barbell or dumbbells over 20kg; garages; anything you drop |
| Drop resistance | Up to 110kg (Sprung PRO 15mm) | Built for everyday free-weight training; go to 30mm or the 43mm Anti-Shock for Olympic lifting and CrossFit (43mm Anti-Shock is rated up to 250kg) |
| Noise and vibration | Good | Noticeably better: more rubber between the weight and the slab |
| Feel underfoot | Firm | Firm with more give for jumps and landings |
| Height | 15mm | 20mm; matters under low door thresholds and in rooms already carpeted |
| Weight per tile | 14kg | Heavier, which is partly why it stays put so well |
| Laying | Loose-laid, no adhesive | Loose-laid, no adhesive |
| Sprung product | 15mm Sprung PRO | 20mm Sprung PRO |
What the extra 5mm actually does
A rubber tile works by spreading the force of a drop across a wider area and giving the weight somewhere to go. Thickness is what makes that possible. At 15mm there is enough rubber to protect a floor from dumbbells up to the rated 110kg drop. At 20mm the same drop lands quieter, transmits less through the slab into the rest of the house, and leaves the tile with more life in it after years of use.
Both tiles are the same solid rubber, made with a binder system rather than the cheapest recycled compound, which is why the range is low-odour. They lay the same way: edge to edge, no glue, cut with a straight edge and a sharp knife.
When 15mm is the right call
Upstairs gyms where every kilogram on the joists counts. Spare rooms with a treadmill and a bench. Yoga and Pilates spaces. Doorways with a low threshold. In all of these the 15mm PRO gives you a proper rubber floor without paying for protection you will not use.
When you should go past 20mm
If you drop a loaded barbell from overhead, or you run a CrossFit-style box, 20mm is the floor and you add a thicker layer where the bar lands: 30mm PRO, or the 43mm Anti-Shock under the platform. The thickness guide maps every activity to a thickness.
Questions people ask
Is 20mm gym flooring too thick for a spare room?
No. 20mm sits comfortably under most doors and on most floors. Where a door sweeps low, a 15mm tile or an edge ramp at the threshold solves it.
Can I put 15mm under a squat rack?
For light racks and controlled lifting it will cope. If you drop weights or lift heavy, choose 20mm so the tile, the slab and your neighbours all last longer.
Do I need to glue either thickness down?
No. Both the 15mm and 20mm Sprung PRO tiles are loose-laid with no adhesive. The rubber's own weight and the tight edges keep the floor flat.
Not sure which room you have? The guide to choosing rubber gym flooring walks through it, or order a sample of each and drop something on them.
Sprung Gym Flooring has floored more than 55,000 UK home gyms since 2020 and carries more than 1,900 customer reviews. Orders ship from our Glasgow warehouse, with free UK mainland delivery over £300. The code SPRUNG30 takes 30% off at checkout.