Brockway Gatsby (1 TOG) with Cloud 9 Radiance (1.3 TOG) gives a combined 1.3 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 Gatsby and Cloud 9 Radiance: combined TOG for underfloor heating

The combined TOG for Brockway Gatsby over Cloud 9 Radiance, worked against the UHMA underfloor heating rule.

1.52.5
1.3TOG in situ
Pass · limit 2.5
Published TOG stack (carpet + underlay)
carpet 1
underlay 1.3
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 1.3, under the 2.5 TOG limit, so Brockway Gatsby with Cloud 9 Radiance is suitable for a standard underfloor heating system. It is also under 1.5 TOG, so it suits a low-temperature heat pump run.
The combined-TOG calculation
CarpetBrockway Gatsby (1 TOG)
UnderlayCloud 9 Radiance (1.3 TOG)
Published sum2.3 TOG
UHMA in-situ correctionminus 1 TOG
Combined in-situ TOG1.3 TOG
Standard UFH limit2.5 TOG
Heat pump targetunder 1.5 TOG

Brockway Gatsby is rated 1 TOG and Cloud 9 Radiance is rated 1.3 TOG. Laid together the combination is what the underfloor heating has to warm through.

The published TOG figures add to 2.3. The UHMA rule subtracts 1 TOG because tests showed real in-situ resistance runs about a TOG below the paper sum, giving 1.3 TOG. That clears both the standard limit and the tighter heat-pump target.

Related checks
Brockway Gatsby TOG value1 TOGCloud 9 Radiance TOG rating1.3 TOGCormar Pimlico with Cloud 9 Radiance1.3 TOG, passCormar Primo Textures Ribbed with Cloud 9 Radiance1.3 TOG, passCormar Primo Textures Weave with Cloud 9 Radiance1.2 TOG, passCormar Apollo Plus with Cloud 9 Radiance1.4 TOG, pass

Questions and answers

Brockway Gatsby and Cloud 9 Radiance: combined TOG for underfloor heating?

Combined in-situ TOG is 1.3, under the 2.5 TOG limit, so Brockway Gatsby with Cloud 9 Radiance is suitable for a standard underfloor heating system. It is also under 1.5 TOG, so it suits a low-temperature heat pump run.