Cormar Natural Berber Deluxe TOG value and underfloor heating
The published Cormar TOG value for Cormar Natural Berber Deluxe and the underlay budget it leaves over a heated floor.
Leaves 0.5 TOG of the combined budget for the carpet on top before the 2.5 TOG limit is reached.
| Range | Cormar Natural Berber Deluxe |
|---|---|
| Construction | wool berber |
| TOG rating | 2 TOG |
| Max underlay TOG for UFH | 1.5 TOG |
Cormar Natural Berber Deluxe is a wool berber with a published TOG value of 2. A dense natural wool berber rated 2.0 TOG. It is close to the whole budget on its own, so it demands the thinnest underlay if it is used over heating at all.
Using the UHMA rule, in-situ resistance is carpet plus underlay minus 1. To keep Cormar Natural Berber Deluxe under the 2.5 TOG limit the underlay must be no more than 1.5 TOG.
TOG measures thermal resistance, so a low number means heat passes through easily. For a floor covering over underfloor heating that is what you want. A comfort underlay chosen for warmth underfoot does the opposite job and is the usual reason a heated floor underperforms after a carpet goes down.
Sources: Cormar Carpets published carpet TOG values · UHMA guidance on underfloor heating with carpet and underlay (combined-TOG rule)