TogCheck
Underlay TOG rating

Cormar Primo Textures Ribbed TOG value and underfloor heating

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

1.52.5
1TOG
Suitable for UFH

Leaves 1.5 TOG of the combined budget for the carpet on top before the 2.5 TOG limit is reached.

PassMarginalFail
Published value
RangeCormar Primo Textures Ribbed
Constructionribbed polypropylene loop
TOG rating1 TOG
Max underlay TOG for UFH2.5 TOG

Cormar Primo Textures Ribbed is a ribbed polypropylene loop with a published TOG value of 1. A ribbed loop-pile at 1.0 TOG. The flat structure lets heat through readily, so almost any underfloor-heating underlay keeps the pair in range.

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

Underlay pairings
Cormar Primo Textures Ribbed with Duralay Technics 5combined 0.56 TOGCormar Primo Textures Ribbed with Duralay Heatflow for Carpetcombined 0.75 TOGCormar Primo Textures Ribbed with Tredaire King (Duralay King)combined 0.8 TOGCormar Primo Textures Ribbed with Duralay Durafit 650combined 1.1 TOGCormar Primo Textures Ribbed with Tredaire Softwalkcombined 2.69 TOGCormar Primo Textures Ribbed with Tredaire Dreamwalkcombined 3.13 TOG

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