Underlay TOG rating

Cormar Apollo Plus TOG value and underfloor heating

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

1.1TOG

Suitable for UFH

Leaves 1.4 TOG of the combined budget for the carpet on top before the 2.5 TOG limit is reached.

PassMarginalFail

Published value

Range	Cormar Apollo Plus
Construction	polypropylene twist
TOG rating	1.1 TOG
Max underlay TOG for UFH	2.4 TOG

Cormar Apollo Plus is a polypropylene twist with a published TOG value of 1.1. A hard-wearing twist rated 1.1 TOG, comfortably within the range that pairs with a low-TOG underlay over a heated floor.

Using the UHMA rule, in-situ resistance is carpet plus underlay minus 1. To keep Cormar Apollo Plus under the 2.5 TOG limit the underlay must be no more than 2.4 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 Apollo Plus with Duralay Technics 5combined 0.66 TOG Cormar Apollo Plus with Duralay Heatflow for Carpetcombined 0.85 TOG Cormar Apollo Plus with Tredaire King (Duralay King)combined 0.9 TOG Cormar Apollo Plus with Duralay Durafit 650combined 1.2 TOG Cormar Apollo Plus with Tredaire Softwalkcombined 2.79 TOG Cormar Apollo Plus with Tredaire Dreamwalkcombined 3.23 TOG

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