Cormar Primo Grande and Tredaire Dreamwalk: combined TOG for underfloor heating
The combined TOG for Cormar Primo Grande over Tredaire Dreamwalk, worked against the UHMA underfloor heating rule.
Combined against the UHMA 2.5 TOG underfloor-heating limit. Under 1.5 also suits a low-temperature heat pump.
| Carpet | Cormar Primo Grande (1.4 TOG) |
|---|---|
| Underlay | Tredaire Dreamwalk (3.13 TOG) |
| Published sum | 4.53 TOG |
| UHMA in-situ correction | minus 1 TOG |
| Combined in-situ TOG | 3.53 TOG |
| Standard UFH limit | 2.5 TOG |
| Heat pump target | under 1.5 TOG |
Cormar Primo Grande is rated 1.4 TOG and Tredaire Dreamwalk is rated 3.13 TOG. Laid together the combination is what the underfloor heating has to warm through.
The published TOG figures add to 4.53, and even after the UHMA 1 TOG in-situ correction the pair sits at 3.53 TOG, 1.03 TOG over the limit. The carpet is fine; the underlay is doing the damage. Keep Cormar Primo Grande 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.
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 / Tredaire Dreamwalk underlay datasheet