Brockway Landmark Castle (1.8 TOG) with Duralay Technics 6 (0.66 TOG) gives a combined 1.46 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 Landmark Castle and Duralay Technics 6: combined TOG for underfloor heating

The combined TOG for Brockway Landmark Castle over Duralay Technics 6, worked against the UHMA underfloor heating rule.

1.52.5
1.46TOG in situ
Pass · limit 2.5
Published TOG stack (carpet + underlay)
carpet 1.8
underlay 0.66
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 1.46, under the 2.5 TOG limit, so Brockway Landmark Castle with Duralay Technics 6 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 Landmark Castle (1.8 TOG)
UnderlayDuralay Technics 6 (0.66 TOG)
Published sum2.46 TOG
UHMA in-situ correctionminus 1 TOG
Combined in-situ TOG1.46 TOG
Standard UFH limit2.5 TOG
Heat pump targetunder 1.5 TOG

Brockway Landmark Castle is rated 1.8 TOG and Duralay Technics 6 is rated 0.66 TOG. Laid together the combination is what the underfloor heating has to warm through.

The published TOG figures add to 2.46. The UHMA rule subtracts 1 TOG because tests showed real in-situ resistance runs about a TOG below the paper sum, giving 1.46 TOG. That clears both the standard limit and the tighter heat-pump target.

Related checks
Brockway Landmark Castle TOG value1.8 TOGDuralay Technics 6 TOG rating0.66 TOGCormar Pimlico with Duralay Technics 60.66 TOG, passCormar Primo Textures Ribbed with Duralay Technics 60.66 TOG, passCormar Primo Textures Weave with Duralay Technics 60.56 TOG, passCormar Apollo Plus with Duralay Technics 60.76 TOG, pass

Questions and answers

Brockway Landmark Castle and Duralay Technics 6: combined TOG for underfloor heating?

Combined in-situ TOG is 1.46, under the 2.5 TOG limit, so Brockway Landmark Castle with Duralay Technics 6 is suitable for a standard underfloor heating system. It is also under 1.5 TOG, so it suits a low-temperature heat pump run.