Brockway Lakeland Herdwick (1.3 TOG) with Duralay Heatflow for Carpet (0.75 TOG) gives a combined 1.05 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 Lakeland Herdwick and Duralay Heatflow for Carpet: combined TOG for underfloor heating

The combined TOG for Brockway Lakeland Herdwick over Duralay Heatflow for Carpet, worked against the UHMA underfloor heating rule.

1.52.5
1.05TOG in situ
Pass · limit 2.5
Published TOG stack (carpet + underlay)
carpet 1.3
underlay 0.75
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 1.05, under the 2.5 TOG limit, so Brockway Lakeland Herdwick with Duralay Heatflow for Carpet 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 Lakeland Herdwick (1.3 TOG)
UnderlayDuralay Heatflow for Carpet (0.75 TOG)
Published sum2.05 TOG
UHMA in-situ correctionminus 1 TOG
Combined in-situ TOG1.05 TOG
Standard UFH limit2.5 TOG
Heat pump targetunder 1.5 TOG

Brockway Lakeland Herdwick is rated 1.3 TOG and Duralay Heatflow for Carpet is rated 0.75 TOG. Laid together the combination is what the underfloor heating has to warm through.

The published TOG figures add to 2.05. The UHMA rule subtracts 1 TOG because tests showed real in-situ resistance runs about a TOG below the paper sum, giving 1.05 TOG. That clears both the standard limit and the tighter heat-pump target.

Related checks
Brockway Lakeland Herdwick TOG value1.3 TOGDuralay Heatflow for Carpet TOG rating0.75 TOGCormar Pimlico with Duralay Heatflow for Carpet0.75 TOG, passCormar Primo Textures Ribbed with Duralay Heatflow for Carpet0.75 TOG, passCormar Primo Textures Weave with Duralay Heatflow for Carpet0.65 TOG, passCormar Apollo Plus with Duralay Heatflow for Carpet0.85 TOG, pass

Questions and answers

Brockway Lakeland Herdwick and Duralay Heatflow for Carpet: combined TOG for underfloor heating?

Combined in-situ TOG is 1.05, under the 2.5 TOG limit, so Brockway Lakeland Herdwick with Duralay Heatflow for Carpet is suitable for a standard underfloor heating system. It is also under 1.5 TOG, so it suits a low-temperature heat pump run.