TogCheck
Underlay TOG rating

Cormar Zenith TOG value and underfloor heating

The published Cormar TOG value for Cormar Zenith and the underlay budget it leaves over a heated floor.

1.52.5
1.5TOG
Suitable for UFH

Leaves 1 TOG of the combined budget for the carpet on top before the 2.5 TOG limit is reached.

PassMarginalFail
Published value
RangeCormar Zenith
Constructionpolypropylene saxony
TOG rating1.5 TOG
Max underlay TOG for UFH2 TOG

Cormar Zenith is a polypropylene saxony with a published TOG value of 1.5. A soft saxony rated 1.5 TOG, in range for underfloor heating with a low-TOG underlay.

Using the UHMA rule, in-situ resistance is carpet plus underlay minus 1. To keep Cormar Zenith under the 2.5 TOG limit the underlay must be no more than 2 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.

Underlay pairings
Cormar Zenith with Duralay Technics 5combined 1.06 TOGCormar Zenith with Duralay Heatflow for Carpetcombined 1.25 TOGCormar Zenith with Tredaire King (Duralay King)combined 1.3 TOGCormar Zenith with Duralay Durafit 650combined 1.6 TOGCormar Zenith with Tredaire Softwalkcombined 3.19 TOGCormar Zenith with Tredaire Dreamwalkcombined 3.63 TOG

Sources: Cormar Carpets published carpet TOG values · UHMA guidance on underfloor heating with carpet and underlay (combined-TOG rule)