Brockway Feldspar has a published TOG value of 1.4. The underlay TOG it can take and stay under the 2.5 TOG combined limit for underfloor heating.

Updated 05 September 2026.

Underlay TOG rating

Brockway Feldspar TOG value and underfloor heating

The published Cormar TOG value for Brockway Feldspar and the underlay budget it leaves over a heated floor.

1.52.5
1.4TOG
Suitable for UFH

Leaves 1.1 TOG of the combined budget for the carpet on top before the 2.5 TOG limit is reached.

PassMarginalFail
Published value
RangeBrockway Feldspar
Construction100% wool
TOG rating1.4 TOG
Max underlay TOG for UFH2.1 TOG

Brockway Feldspar is a 100% wool with a published TOG value of 1.4. Feldspar is a 100% wool carpet rated 1.4 TOG, where the underlay choice decides whether the pair clears the combined limit over a heated floor.

Using the UHMA rule, in-situ resistance is carpet plus underlay minus 1. To keep Brockway Feldspar under the 2.5 TOG limit the underlay must be no more than 2.1 TOG.

TOG measures thermal resistance, so a low number means heat passes through easily. For a floor covering over underfloor heating that is what you want. A comfort underlay chosen for warmth underfoot does the opposite job and is the usual reason a heated floor underperforms after a carpet goes down.

Underlay pairings
Brockway Feldspar with Duralay Technics 5combined 0.96 TOGBrockway Feldspar with Duralay Heatflow for Carpetcombined 1.15 TOGBrockway Feldspar with Tredaire King (Duralay King)combined 1.2 TOGBrockway Feldspar with Duralay Durafit 650combined 1.5 TOGBrockway Feldspar with Tredaire Softwalkcombined 3.09 TOGBrockway Feldspar with Tredaire Dreamwalkcombined 3.53 TOG

Questions and answers

What is the range of the Brockway Feldspar TOG value and underfloor heating?

Brockway Feldspar

What is the construction of the Brockway Feldspar TOG value and underfloor heating?

100% wool

What is the tog rating of the Brockway Feldspar TOG value and underfloor heating?

1.4 TOG

What is the max underlay tog for ufh of the Brockway Feldspar TOG value and underfloor heating?

2.1 TOG