Brockway Helvellyn has a published TOG value of 1.69. 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 Helvellyn TOG value and underfloor heating

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

1.52.5
1.69TOG
Suitable for UFH

Leaves 0.81 TOG of the combined budget for the carpet on top before the 2.5 TOG limit is reached.

PassMarginalFail
Published value
RangeBrockway Helvellyn
Construction100% wool
TOG rating1.69 TOG
Max underlay TOG for UFH1.81 TOG

Brockway Helvellyn is a 100% wool with a published TOG value of 1.69. Helvellyn is a 100% wool carpet rated 1.69 TOG. A low-TOG underlay is essential for it to clear the combined limit over underfloor heating.

Using the UHMA rule, in-situ resistance is carpet plus underlay minus 1. To keep Brockway Helvellyn under the 2.5 TOG limit the underlay must be no more than 1.81 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 Helvellyn with Duralay Technics 5combined 1.25 TOGBrockway Helvellyn with Duralay Heatflow for Carpetcombined 1.44 TOGBrockway Helvellyn with Tredaire King (Duralay King)combined 1.49 TOGBrockway Helvellyn with Duralay Durafit 650combined 1.79 TOGBrockway Helvellyn with Tredaire Softwalkcombined 3.38 TOGBrockway Helvellyn with Tredaire Dreamwalkcombined 3.82 TOG

Questions and answers

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

Brockway Helvellyn

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

100% wool

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

1.69 TOG

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

1.81 TOG