TogCheck
Underlay TOG rating

Cormar Apollo Elite TOG value and underfloor heating

The published Cormar TOG value for Cormar Apollo Elite 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 Apollo Elite
Constructionpolypropylene saxony
TOG rating1.5 TOG
Max underlay TOG for UFH2 TOG

Cormar Apollo Elite is a polypropylene saxony with a published TOG value of 1.5. A softer saxony version of the Apollo family at 1.5 TOG. Underlay choice decides whether it clears the combined limit over underfloor heating.

Using the UHMA rule, in-situ resistance is carpet plus underlay minus 1. To keep Cormar Apollo Elite 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

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