TogCheck
Combined TOG result

Cormar Ultimate Sensation and Duralay System Ten: combined TOG for underfloor heating

The combined TOG for Cormar Ultimate Sensation over Duralay System Ten, worked against the UHMA underfloor heating rule.

1.52.5
2.75TOG in situ
Fail · limit 2.5
Published TOG stack (carpet + underlay)
carpet 2.2
underlay 1.55
limit

Combined against the UHMA 2.5 TOG underfloor-heating limit. Under 1.5 also suits a low-temperature heat pump.

Carpet TOGUnderlay TOGPassMarginalFail
Combined in-situ TOG is 2.75, above the 2.5 TOG limit, so Cormar Ultimate Sensation with Duralay System Ten is not suitable for underfloor heating. Keep the carpet and switch to a low-TOG underlay.
The combined-TOG calculation
CarpetCormar Ultimate Sensation (2.2 TOG)
UnderlayDuralay System Ten (1.55 TOG)
Published sum3.75 TOG
UHMA in-situ correctionminus 1 TOG
Combined in-situ TOG2.75 TOG
Standard UFH limit2.5 TOG
Heat pump targetunder 1.5 TOG

Cormar Ultimate Sensation is rated 2.2 TOG and Duralay System Ten is rated 1.55 TOG. Laid together the combination is what the underfloor heating has to warm through.

The published TOG figures add to 3.75, and even after the UHMA 1 TOG in-situ correction the pair sits at 2.75 TOG, 0.25 TOG over the limit. The carpet is fine; the underlay is doing the damage. Keep Cormar Ultimate Sensation and drop to a low-TOG underlay such as Duralay Heatflow for Carpet (0.75 TOG) or Duralay Technics 5 (0.56 TOG), which brings the combined figure back into range.

The underlay to buy instead
Search Amazon for Duralay Heatflow for Carpet (0.75 TOG)affiliate searchFind Duralay Heatflow for Carpet (0.75 TOG) on eBayaffiliateSearch Amazon for Duralay Technics 5 (0.56 TOG)affiliate searchFind Duralay Technics 5 (0.56 TOG) on eBayaffiliate
Related checks

Sources: UHMA guidance on underfloor heating with carpet and underlay (combined-TOG rule) · How to calculate a combined TOG (UHMA formula, worked) · Cormar Carpets published carpet TOG values · Interfloor / Duralay System Ten underlay datasheet