Brockway Dimensions Plain 50 (1.57 TOG) with Tredaire Colours Red (1.65 TOG) gives a combined 2.22 in-situ TOG. Whether that passes the 2.5 TOG underfloor heating limit and what to do.

Updated 05 September 2026.

Combined TOG result

Brockway Dimensions Plain 50 and Tredaire Colours Red: combined TOG for underfloor heating

The combined TOG for Brockway Dimensions Plain 50 over Tredaire Colours Red, worked against the UHMA underfloor heating rule.

1.52.5
2.22TOG in situ
Marginal · limit 2.5
Published TOG stack (carpet + underlay)
carpet 1.57
underlay 1.65
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 2.22, under the 2.5 TOG limit, so Brockway Dimensions Plain 50 with Tredaire Colours Red is suitable for a standard underfloor heating system. It is above 1.5 TOG, so on a low-temperature heat pump run choose a thinner underlay.
The combined-TOG calculation
CarpetBrockway Dimensions Plain 50 (1.57 TOG)
UnderlayTredaire Colours Red (1.65 TOG)
Published sum3.22 TOG
UHMA in-situ correctionminus 1 TOG
Combined in-situ TOG2.22 TOG
Standard UFH limit2.5 TOG
Heat pump targetunder 1.5 TOG

Brockway Dimensions Plain 50 is rated 1.57 TOG and Tredaire Colours Red is rated 1.65 TOG. Laid together the combination is what the underfloor heating has to warm through.

The published TOG figures add to 3.22. The UHMA rule subtracts 1 TOG because tests showed real in-situ resistance runs about a TOG below the paper sum, giving 2.22 TOG. On a heat pump running low flow temperatures the floor has less heat to push, so aim under 1.5 TOG and prefer the thinnest underlay in this range.

Related checks
Brockway Dimensions Plain 50 TOG value1.57 TOGTredaire Colours Red TOG rating1.65 TOGCormar Pimlico with Tredaire Colours Red1.65 TOG, passCormar Primo Textures Ribbed with Tredaire Colours Red1.65 TOG, passCormar Primo Textures Weave with Tredaire Colours Red1.55 TOG, passCormar Apollo Plus with Tredaire Colours Red1.75 TOG, pass

Questions and answers

Brockway Dimensions Plain 50 and Tredaire Colours Red: combined TOG for underfloor heating?

Combined in-situ TOG is 2.22, under the 2.5 TOG limit, so Brockway Dimensions Plain 50 with Tredaire Colours Red is suitable for a standard underfloor heating system. It is above 1.5 TOG, so on a low-temperature heat pump run choose a thinner underlay.