Ranking Wood Thermal Conductivity for Custom Epoxy River Tables

Understanding Heat Flow in Tabletop Slabs

When selecting timber for a custom epoxy river table, physical properties like density and thermal conductivity play a quiet yet significant role in how the finished surface performs. Thermal conductivity, measured in watts per meter-kelvin (W/(m·K)), describes the rate at which heat moves through a material. Sourced from the technical documentation published by CIRAD (the French agricultural research and international cooperation organization), the compiled data shows clear variation across hardwood and softwood species.

While wood is recognized across the board as a thermal insulator rather than a conductor, differences exist between species. Understanding these subtle differences helps woodworkers and clients understand surface feel, temperature distribution, and safe day-to-day use of wood and resin surfaces.

Why Denser Woods Conduct More Heat

Wood is naturally composed of cell walls surrounded by tiny cavities that trap air. Air is a poor conductor of heat. In light, porous woods with low specific gravity, a greater proportion of the wood’s volume consists of these empty spaces. Consequently, low-density timbers resist heat transfer effectively.

As timber density increases, the solid mass of cell wall material increases and the volume of trapped air decreases. Denser timbers have less insulating air space, allowing heat to pass through the solid fibers more readily. For example, Erimado has a low thermal conductivity of 0.11 W/(m·K) paired with a specific gravity of 0.26. In contrast, exceptionally dense timbers such as Grenadillo reach a thermal conductivity of 0.40 W/(m·K) alongside a specific gravity of 1.29. Across hundreds of tested species, thermal conductivity climbs predictably alongside specific gravity.

Why Wood Feels Warmer Than Stone or Metal

The sensation of warmth when touching a surface does not depend solely on its resting temperature. At ordinary room conditions, a block of wood, a slab of granite, and a sheet of steel will share the same ambient temperature. However, skin temperature is usually warmer than the surrounding room.

When skin contacts stone or metal, those materials conduct heat away from the hand very quickly, resulting in an immediate sensation of cold. Wood conducts heat at a much slower rate. Because heat is not rapidly drawn away from your fingertips, the surface feels warm, soft, and inviting to the touch. This low rate of heat transfer gives solid wood furniture its tactile comfort compared to stone counters or steel desks.

Species Ranking and Thermal Conductivity Data

The following dataset, compiled from mature wood records in CIRAD Tropix technical sheets, ranks species from lowest to highest thermal conductivity:

Wood	Thermal conductivity W/(m·K)	Specific gravity
Erimado	0.11	0.26
Ceiba	0.12	0.32
Sumauma	0.12	0.32
Alstonia	0.13	0.36
Pashaco / paricá	0.13	0.35
Cryptomeria	0.14	0.38
Jacaranda	0.15	0.43
Kapokier	0.15	0.41
Marupa	0.15	0.41
Canon ball	0.16	0.45
East african bombax	0.16	0.46
Geronggang	0.16	0.45
Jelutong	0.16	0.45
European Poplar	0.16	0.45
Pulai	0.16	0.45
Sandbox	0.16	0.45
Sesendok	0.16	0.45
European Spruce	0.16	0.45
African canarium	0.17	0.49
Antiaris	0.17	0.47
Capomo	0.17	0.47
Radiata Pine (European Plantation)	0.17	0.50
Faveira	0.17	0.47
European Silver Fir	0.17	0.49
Guanacaste	0.17	0.49
Mountain Pine (Hooked Pine)	0.17	0.50
Ilomba	0.17	0.49
Ovoga	0.17	0.47
Patula pine	0.17	0.49
Yemane	0.17	0.49
African cordia	0.18	0.50
African walnut	0.18	0.53
Agba	0.18	0.52
Black wattle	0.18	0.52
Atlas Cedar	0.18	0.51
Cedrorana	0.18	0.51
Copaiba	0.18	0.50
Dalli	0.18	0.52
Dukali / amapa	0.18	0.52
Ekoune	0.18	0.53
Idigbo	0.18	0.50
Kauri	0.18	0.53
Kumbi	0.18	0.50
Magas	0.18	0.50
Musizi	0.18	0.52
Olon	0.18	0.52
Quaruba	0.18	0.52
Suren	0.18	0.50
Ariella	0.19	0.56
Gedu nohor	0.19	0.55
Gombé rouge	0.19	0.57
Louro branco	0.19	0.54
Maritime Pine	0.19	0.55
Morototo	0.19	0.55
Ogea	0.19	0.55
Onzabili	0.19	0.55
Owui	0.19	0.55
Perupok	0.19	0.55
Scots Pine	0.19	0.55
Abura	0.20	0.60
Andoung	0.20	0.59
Aningeria	0.20	0.57
Anzèm / nténé	0.20	0.58
Cedrinho	0.20	0.60
Cerejeira	0.20	0.59
European Cherry	0.20	0.60
European Larch	0.20	0.60
Freijo	0.20	0.58
Iatandza	0.20	0.60
Nieuk	0.20	0.58
Nyatoh	0.20	0.57
Ossabel	0.20	0.59
Ossoko	0.20	0.59
Ozigo	0.20	0.59
Pterygota	0.20	0.59
Djedoe	0.21	0.62
Durian	0.21	0.62
Ekop	0.21	0.62
Gombé towé	0.21	0.65
Gommier	0.21	0.61
Scented Guarea (Bossé Clair)	0.21	0.63
Igaganga	0.21	0.61
Kedondong	0.21	0.63
Melunak	0.21	0.62
Mersawa	0.21	0.63
Okwen	0.21	0.62
Peruvian Walnut	0.21	0.61
Tauari	0.21	0.62
Utile	0.21	0.62
White seraya	0.21	0.62
European Sweet Chestnut	0.22	0.64
Sycamore Maple (Great Maple)	0.22	0.64
Iroko	0.22	0.64
Jacareuba	0.22	0.65
Jequitiba	0.22	0.64
Kanda brun	0.22	0.67
Kembang semangkok	0.22	0.67
Kurokai	0.22	0.64
Landa	0.22	0.66
Louro vermelho	0.22	0.66
Makoré	0.22	0.67
Mambode	0.22	0.66
Mansonia	0.22	0.66
Maporokon	0.22	0.66
Mumuli	0.22	0.65
Odoko	0.22	0.66
Red grandis	0.22	0.60
Rubberwood	0.22	0.65
Sepetir	0.22	0.64
Sterculia	0.22	0.64
Tchitola	0.22	0.64
European Walnut	0.22	0.66
Abarco	0.23	0.68
European Ash	0.23	0.68
Berlinia	0.23	0.70
Catucaém / louro faia	0.23	0.70
Cow tree	0.23	0.69
Dabema	0.23	0.70
Gerutu	0.23	0.68
Black Guarea (Bossé Foncé)	0.23	0.68
Guariuba	0.23	0.69
Haldu	0.23	0.70
Kosipo	0.23	0.69
Mengkulang	0.23	0.68
Merawan	0.23	0.70
Niangon	0.23	0.70
Padauk amboina	0.23	0.70
Pyinma	0.23	0.70
Rengas	0.23	0.70
Safukala	0.23	0.68
Alumbi	0.24	0.74
Angoa	0.24	0.72
Ayan	0.24	0.73
European Beech	0.24	0.71
Benguet pine	0.24	0.71
Bintangor	0.24	0.74
Cardeiro / Cedrinho	0.24	0.72
Dakama	0.24	0.71
Diania	0.24	0.72
Douka	0.24	0.72
Etimoe	0.24	0.71
Gheombi	0.24	0.72
Izombe	0.24	0.72
Kanda rose	0.24	0.71
Kasai	0.24	0.72
Mandioqueira	0.24	0.74
Manil / Manni	0.24	0.71
Merkus pine	0.24	0.73
European Oak	0.24	0.74
Ossimiale	0.24	0.71
Punah	0.24	0.73
Simpoh	0.24	0.71
White sterculia	0.24	0.74
Angelim amargoso	0.25	0.75
Baracara	0.25	0.77
Beli	0.25	0.77
Bilinga / Opepe	0.25	0.76
Brazil nut	0.25	0.77
Curupixa	0.25	0.75
Danta	0.25	0.76
Longui	0.25	0.75
Mango (Machang)	0.25	0.76
Melancieira	0.25	0.76
Merpauh	0.25	0.75
Oboto	0.25	0.75
Ohia	0.25	0.75
African Padauk	0.26	0.79
Afzelia	0.26	0.80
Alan / Alan-Batu	0.26	0.80
Angelim pedra	0.26	0.80
Basralocus	0.26	0.79
Essia	0.26	0.80
Garapa	0.26	0.79
Keledang	0.26	0.80
Keruing	0.26	0.79
Limbali	0.26	0.81
Macacauba	0.26	0.79
Mutenye	0.26	0.79
Osanga	0.26	0.80
Piquia	0.26	0.81
Piquiarana	0.26	0.80
Resak	0.26	0.80
Senegal mahogany	0.26	0.78
Tasmanian oak	0.26	0.80
Tatajuba	0.26	0.80
Timborana	0.26	0.80
Yellowheart	0.26	0.81
Zebrano	0.26	0.79
Batibatra	0.27	0.83
Brown sterculia	0.27	0.84
Cupiuba	0.27	0.84
Difou	0.27	0.84
Lati	0.27	0.82
Merbau	0.27	0.83
Ovangkol	0.27	0.82
Pau marfim	0.27	0.82
Pau mulato	0.27	0.83
Amesclào	0.28	0.87
Angelin	0.28	0.86
Bitis	0.28	0.85
Idéwa	0.28	0.87
Itauba	0.28	0.86
Kelat	0.28	0.86
Moabi	0.28	0.87
Pakuri	0.28	0.85
Red balau	0.28	0.87
Wamba	0.28	0.87
Wenge	0.28	0.87
Angueuk	0.29	0.88
Bodioa	0.29	0.89
Chengal	0.29	0.91
Coconut wood	0.29	0.90
Giam	0.29	0.89
Goiabao	0.29	0.91
Macucu de paca	0.29	0.88
Manchiche	0.29	0.91
Manniballi	0.29	0.90
Moral	0.29	0.88
Niove	0.29	0.88
Okan	0.29	0.91
Ozouga	0.29	0.89
Pyinkado	0.29	0.88
Sonokeling Rosewood	0.29	0.89
Sougué	0.29	0.89
Tali / Missanda	0.29	0.91
Tamarindo (Groçai-rosa)	0.29	0.90
Vêne	0.29	0.89
Vésámbata	0.29	0.91
Wallaba	0.29	0.88
Yellow balau	0.29	0.91
Andok	0.30	0.93
Araracanga	0.30	0.94
Billian	0.30	0.93
Eyoum	0.30	0.94
Mecrussé	0.30	0.93
Muhuhu	0.30	0.93
Mukulungu	0.30	0.94
Olène	0.30	0.92
Pucté	0.30	0.94
Tanimbuca	0.30	0.93
Wacapou	0.30	0.92
Ananta	0.31	0.96
Cabreuva	0.31	0.95
Mubala	0.31	0.95
Sapucaia	0.31	0.96
Ceylon Satinwood	0.31	0.98
Uchy	0.31	0.96
Coula	0.32	1.01
Manilkara	0.32	1.00
Tamalan Rosewood	0.32	1.00
Alep	0.33	1.05
Dina	0.33	1.02
Keranji	0.33	1.05
Mora	0.33	1.03
Rosewood Para	0.33	1.04
Snakewood	0.33	1.03
Abiurana vermelha	0.34	1.09
Angelim vermelho	0.34	1.07
Cumaru / Tonka	0.34	1.07
Ekki	0.34	1.06
Eveuss	0.34	1.06
Congotali	0.35	1.10
Massaranduba	0.35	1.10
Muirapiranga / Bloodwood	0.35	1.10
Preciosa	0.35	1.12
Macassar Ebony (Ebène Veinée d’Asie)	0.38	1.20
Wamara	0.38	1.20
Grenadillo / Grenadille d’Afrique	0.40	1.29

Data compiled by BigEpoxy from individual CIRAD Tropix 7 technical sheets (average values for mature wood).

Key Patterns in the Thermal Data

• Lightweight Species: Woods like Erimado (0.11 W/(m·K), specific gravity 0.26), Ceiba (0.12 W/(m·K), specific gravity 0.32), and Cryptomeria (0.14 W/(m·K), specific gravity 0.38) display the lowest conductivity rates in the collection.
• Standard Joinery Hardwoods and Softwoods: Common furniture species fall directly into the middle range. European Spruce and Jelutong test at 0.16 W/(m·K) (specific gravity 0.45), Scots Pine sits at 0.19 W/(m·K) (specific gravity 0.55), European Cherry reaches 0.20 W/(m·K) (specific gravity 0.60), and European Oak measures 0.24 W/(m·K) (specific gravity 0.74).
• Dense Tropical Hardwoods: Heavy exotic species cluster near the top of the spectrum. African Padauk measures 0.26 W/(m·K) (specific gravity 0.79), Wenge registers 0.28 W/(m·K) (specific gravity 0.87), Cumaru tests at 0.34 W/(m·K) (specific gravity 1.07), and Grenadillo tops the list at 0.40 W/(m·K) (specific gravity 1.29).

Practical Notes for Hot Dishes on Wood and Epoxy Tabletops

The insulating nature of wood creates distinct practical considerations for tabletops:

• Localized Heat Retention: Because wood does not rapidly disperse thermal energy sideways, heat from a hot plate or serving bowl stays concentrated directly beneath the dish rather than dissipating into the surrounding slab.
• Epoxy Thermal Limits: Pouring resin cures into a solid polymer, but cured epoxy remains sensitive to high temperatures. Direct contact with hot cookware can cause clouding, surface softening, ring marks, or indentation. Epoxy formulators outline maximum service temperatures in their technical sheets.
• Differential Movement: An epoxy river table bonds two distinct materials together. Concentrated thermal stress placed directly on a joint line between wood and cured epoxy can cause localized expansion stresses.
• Protective Habits: Regardless of whether a slab has a conductivity rating of 0.11 W/(m·K) or 0.40 W/(m·K), always use trivets, insulated hot pads, or coasters under hot cookware and heated dishware to preserve the resin and wood finish.

Sources

• CIRAD Tropix 7 technical sheets (index)

Published October 31, 2026. Sources are linked in the text.

Header image: original graphic by BigEpoxy.com.