Duralay Durafit 500 is rated 0.83 TOG at 5.25 mm. Whether it works over underfloor heating and which carpets it pairs with under the 2.5 TOG limit.

Updated 05 September 2026.

Underlay TOG rating

Duralay Durafit 500 TOG rating and underfloor heating

The published TOG and datasheet figures for Duralay Durafit 500, and what it means over a heated floor.

1.52.5
0.83TOG
Suitable for UFH

Leaves 1.67 TOG of the combined budget for the carpet on top before the 2.5 TOG limit is reached.

PassMarginalFail
Duralay Durafit 500 is rated 0.83 TOG and is suitable for underfloor heating. It leaves 2.67 TOG of the combined budget for the carpet on top before the 2.5 TOG limit is reached.
Published datasheet
ManufacturerInterfloor (Duralay)
TOG rating0.83 TOG
Thickness5.25 mm
Densitycrumb rubber
Soundsponge/crumb rubber
Underfloor heatingSuitable

Durafit 500 is a thin 5.25 mm double-stick crumb-rubber contract underlay rated 0.83 TOG. It stays well under the 1.3 TOG underlay ceiling, so it passes heat readily and pairs safely with low-TOG carpets over a heated floor.

Against the UHMA combined-TOG rule, in-situ resistance is the carpet TOG plus the underlay TOG minus 1. With this underlay at 0.83 TOG, a carpet up to 2.67 TOG keeps the pair under the 2.5 TOG limit.

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.

Pairings and alternatives
Cormar Pimlico with Duralay Durafit 500combined 0.83 TOGCormar Primo Textures Ribbed with Duralay Durafit 500combined 0.83 TOGCormar Primo Textures Weave with Duralay Durafit 500combined 0.73 TOGCormar Apollo Plus with Duralay Durafit 500combined 0.93 TOGCormar Apollo Elite with Duralay Durafit 500combined 1.33 TOGCormar Fairisle with Duralay Durafit 500combined 1.33 TOG

Questions and answers

What is the manufacturer of the Duralay Durafit 500 TOG rating and underfloor heating?

Interfloor (Duralay)

What is the tog rating of the Duralay Durafit 500 TOG rating and underfloor heating?

0.83 TOG

What is the thickness of the Duralay Durafit 500 TOG rating and underfloor heating?

5.25 mm

What is the density of the Duralay Durafit 500 TOG rating and underfloor heating?

crumb rubber