Cormar Natural Berber Deluxe (2 TOG) with Cloud 9 Cirrus (2.6 TOG) gives a combined 3.6 in-situ TOG. Whether that passes the 2.5 TOG underfloor heating limit and what to do.
Updated 05 September 2026.
Cormar Natural Berber Deluxe and Cloud 9 Cirrus: combined TOG for underfloor heating
The combined TOG for Cormar Natural Berber Deluxe over Cloud 9 Cirrus, worked against the UHMA underfloor heating rule.
Combined against the UHMA 2.5 TOG underfloor-heating limit. Under 1.5 also suits a low-temperature heat pump.
| Carpet | Cormar Natural Berber Deluxe (2 TOG) |
|---|---|
| Underlay | Cloud 9 Cirrus (2.6 TOG) |
| Published sum | 4.6 TOG |
| UHMA in-situ correction | minus 1 TOG |
| Combined in-situ TOG | 3.6 TOG |
| Standard UFH limit | 2.5 TOG |
| Heat pump target | under 1.5 TOG |
Cormar Natural Berber Deluxe is rated 2 TOG and Cloud 9 Cirrus is rated 2.6 TOG. Laid together the combination is what the underfloor heating has to warm through.
The published TOG figures add to 4.6, and even after the UHMA 1 TOG in-situ correction the pair sits at 3.6 TOG, 1.1 TOG over the limit. The carpet is fine; the underlay is doing the damage. Keep Cormar Natural Berber Deluxe and drop to a low-TOG underlay such as Duralay Heatflow for Carpet (0.75 TOG) or Duralay Technics 5 (0.56 TOG), which brings the combined figure back into range.
Questions and answers
Cormar Natural Berber Deluxe and Cloud 9 Cirrus: combined TOG for underfloor heating?
Combined in-situ TOG is 3.6, above the 2.5 TOG limit, so Cormar Natural Berber Deluxe with Cloud 9 Cirrus is not suitable for underfloor heating. Keep the carpet and switch to a low-TOG underlay.