Trivets: How to choose between wood, cork, and silicone
A trivet has one purpose: to prevent heat from a cooking dish from reaching the tabletop. Three materials account for most of the market today—solid wood, cork and silicone—and they behave differently when exposed to heat, weight and cleaning. This article compares the three using verifiable criteria: thermal conductivity, effective thickness, temperature resistance, food-contact regulations, care and lifespan. There is no single answer to the question “how to choose a trivet”; it depends on the type of dish you place on it, the surface you need to protect and how often you use it.
In brief
- A trivet’s performance depends first on its thickness, then on its material: thermal resistance is calculated by dividing the thickness by the material’s conductivity.
- Oak, beech and black locust (false acacia) have a thermal conductivity of 0.18 W/(m.K), according to the official values in the Th-bât Rules.
- Expanded cork has a conductivity of 0.037–0.044 W/(m.K), making it about four times less conductive than solid wood, but it deforms under a heavy casserole dish.
- Silicone does not insulate better than wood (at least 0.2 W/(m.K)), and in France it is subject to a specific regulatory framework, the decree of November 25, 1992. The DGCCRF regularly identifies non-compliant products among imported items.
- Solid wood is the only one of the three materials that can be repaired: a light sanding is enough to remove a mark.
What a trivet is really for
A trivet has two purposes. It creates a thermal barrier between the bottom of a hot container and the table, and it distributes a concentrated load over a wider area. The first has to do with materials physics; the second, with their rigidity.
An oven dish, a cast-iron casserole, a ceramic dish: the temperature on the bottom when it is set on the table is generally between 150 and 220 °C, and it drops quickly. A varnished wooden table, however, can be marked at much lower temperatures: the varnish turns cloudy, veneer adhesives are affected, and a tablecloth offers no protection. The trivet must absorb the heat during this brief period of contact, which lasts a few dozen minutes.
Its second purpose is often overlooked: stability. A 24 cm cast-iron casserole filled with food can easily weigh more than 5 kg. A trivet that dips or slips under that load is failing, regardless of its thermal performance.
Thermal conductivity: what the reference values tell us
Thermal conductivity, denoted by lambda and expressed in W/(m.K), measures how easily a material allows heat to pass through it. The lower the value, the more the material slows heat transfer.
The Th-bât Rules, Materials Booklet, published by the ministry responsible for construction provide values for different wood species. Oak (sessile and pedunculate), beech, ash and black locust, also known as false acacia, are all listed at 0.18 W/(m.K). Medium-density hardwoods, a category covering most woods used for tableware, are also listed at 0.18 W/(m.K).
For cork, the Guide to Insulating Materials from the Espace Info Énergie network gives a conductivity of 0.037 to 0.044 W/(m.K) for expanded cork, with a density of 65 to 180 kg/m³. Cork owes its performance to its cellular structure, which traps air, and to suberin, the natural resin in the bark of the cork oak, which makes it rot-resistant.
Finally, silicone. Materials data published by AZoM, based on the Granta Design database, gives silicone rubber a thermal conductivity of between 0.2 and 2.55 W/(m.K), with the upper value corresponding to formulations containing conductive additives. In other words, ordinary kitchen silicone conducts heat at least as well as oak, and often better. The common belief that “silicone insulates” comes from how it is used, not from its properties.
| Material | Thermal conductivity, lambda | Source |
|---|---|---|
| Expanded cork | 0.037 to 0.044 W/(m.K) | Guide to Insulating Materials, Espace Info Énergie network |
| Oak, beech, ash, black locust | 0.18 W/(m.K) | Th-bât Rules, Materials Booklet |
| Silicone (rubber) | from 0.2 W/(m.K) | AZoM / Granta Design |
Thickness matters more than the material
Conductivity alone does not tell us anything useful. What protects the table is thermal resistance, R, which is the thickness divided by the conductivity and is expressed in m².K/W. Let’s apply this calculation to sizes that are actually sold.
- A 15 mm solid-wood trivet: 0.015 / 0.18 = 0.083 m².K/W
- An 8 mm cork trivet: 0.008 / 0.040 = 0.20 m².K/W
- A 4 mm silicone trivet: 0.004 / 0.20 = 0.020 m².K/W
Cork performs much better at a comparable thickness, which makes sense for an insulating material. Silicone comes a long way behind, not because the material is poor, but because it is sold in thin mats. A 4 mm silicone trivet offers about four times less thermal resistance than a 15 mm oak board. That is the first figure to keep in mind.
These estimates do not take geometry into account. A slatted trivet or one with a ribbed surface creates an air gap between the dish and the surface, further improving overall performance. In practice, the surfaces are never in full contact.
As the French forest and timber industry association explains on bois.com, wood insulates about six times better than brick and 350 times better than steel. For a tabletop item, this means that a 15 to 20 mm board is sufficient for almost all household uses.
Temperature resistance: three different behaviors
Wood
Wood does not melt or soften. Its limitation is not thermal in the strict sense, but hygroscopic. Repeated contact with the very hot bottom of a casserole dries out the fibers locally, which can darken the surface and, over time, cause fine cracks if the piece was not properly dried before it was made. Wood that has been properly stabilized before cutting and then oiled can withstand these cycles for years without visible damage.
It is also the only one of the three materials that can be repaired. A dark mark, a ring or a grease stain: fine sanding followed by re-oiling will restore the surface to its original condition.
Cork
Cork withstands dry heat well and does not rot. Its limitations are mechanical. Cork trivets are most often made from agglomerated cork, with granules bonded together, and this structure compresses under a concentrated load. A heavy casserole leaves an indentation. The porous surface also holds grease splashes and stains that cannot be removed.
Silicone
Silicone can withstand high operating temperatures. The Granta Design database gives a maximum operating temperature of between 500 and 560 K, or about 227 to 287 °C, in line with the 230 °C generally stated by cookware manufacturers. For a trivet, this is a comfortable margin.
The real issue is not temperature resistance, but silicone quality. In France, silicone elastomer materials intended for food contact are subject to a specific regulation, the decree of November 25, 1992, which sets out a list of authorized substances and migration limits, including a limit on free volatile organic matter. This is noted in the government’s response to National Assembly written question No. 4071, published on February 28, 2023. The same response states that the DGCCRF inspects these products every year and that “non-compliance is frequently detected in imported products.” European regulations on materials intended to come into contact with food are also under revision to introduce specific requirements for silicones, including requirements for their degradation products.
However, this needs to be kept in perspective. These inspections mainly concern molds and cookware that are heated to high temperatures in an oven and come into direct, prolonged contact with fatty foods. A silicone trivet does not fall into this category: it is not heated itself and does not touch food. The risk of migration is therefore structurally lower. It is still worth checking the product’s origin and declaration of conformity, rather than worrying about the use itself.
For wider context, a DGCCRF survey of materials intended to come into contact with food found a non-compliance rate of nearly 16% among 374 samples taken across all material types. The DGCCRF technical sheet on rubber also explicitly states that silicone elastomers are not covered by the same decree as other rubbers, which explains the frequent confusion between the two groups.
Comparison table: wood, cork and silicone
| Criterion | Solid wood | Agglomerated cork | Silicone |
|---|---|---|---|
| Thermal conductivity | 0.18 W/(m.K) (oak, beech, black locust) | 0.037 to 0.044 W/(m.K) | from 0.2 W/(m.K) |
| Typical thickness | 15 to 20 mm | 6 to 10 mm | 3 to 6 mm |
| Estimated thermal resistance | about 0.08 m².K/W | about 0.20 m².K/W | about 0.02 m².K/W |
| Resistance to heavy loads | rigid, does not deform | compresses and dents | flexible, gets squashed |
| Stain resistance | good if oiled; can be sanded | poor; porous surface | good, but holds grease |
| Repairable | yes, by sanding and oiling | no | no |
| Specific regulatory framework | inert material; no migration expected | inert material | decree of November 25, 1992; annual DGCCRF inspections |
| Expected lifespan | long; develops a patina | average; wears out | average; deforms and yellows |
Care and lifespan
Solid wood requires simple but regular care: wash with warm water and a soft sponge, dry immediately, and never put it in the dishwasher or soak it. Applying a thin coat of food-safe oil periodically nourishes the fibers and protects the surface. The same steps apply to all wooden kitchen items, as explained in the guide to caring for wooden utensils.
Cork should be cleaned dry or with a barely damp cloth. It does not do well with a lot of water, which can loosen the binder in agglomerated cork, or with greasy products. A stain will become permanent.
Silicone can go in the dishwasher, its strongest selling point. On the other hand, it holds grease on its surface, attracts dust through static electricity, and deforms or yellows over time. None of these three defects can be fixed.
How to choose a trivet based on how you actually use it
Let’s reframe the original question in terms of what you put on the table.
A cast-iron casserole, a heavy dish, something built to last. Solid wood. Rigidity comes first, the thermal resistance of a 15 to 20 mm board is sufficient, and the item will not deform under the load. This is the most common setup in France.
A scorching-hot dish straight from the oven, set on a delicate table. Cork, or a thick wooden trivet. If the surface to protect is a varnished tabletop or delicate veneer, cork’s higher thermal resistance is worthwhile. You then have to accept the indentation a heavy load will leave.
Heavy use, on a worktop rather than a table. Silicone. It can be washed, is not affected by water or knocks, and its appearance does not matter. It is a kitchen tool, not a tabletop accessory.
An item meant to last and be seen. Solid wood again, for a reason that is no longer technical: it ages without deteriorating, and marks can be repaired. It is the only one of the three that gains something with age.
Common mistakes and misconceptions
“Silicone insulates better because it is made for heat.” The first part is false. Silicone tolerates heat; it does not stop it. Its conductivity is higher than oak’s, and it is typically three to four times thinner. It withstands heat, but it does not insulate.
“Wood will burn.” Not at the temperatures of a serving dish. The actual risk is that the surface will darken as it dries out locally, and this can be fixed by sanding.
“Cork is fragile.” Not when it comes to heat. Cork is rot-resistant and withstands dry heat very well. Its weakness is mechanical: it compresses, dents and stains.
“All trivets protect equally well.” There is about a fourfold difference in thermal resistance between a 4 mm silicone mat and a 15 mm wooden board. That is not a negligible difference.
FAQ
What is the minimum thickness for a wooden trivet?
A simple calculation gives us an approximate range: with a conductivity of 0.18 W/(m.K), a thickness of at least 12 to 15 mm is needed to exceed a thermal resistance of 0.07 m².K/W. Below 10 mm, there is little margin for a cast-iron casserole.
Does cork protect better than wood?
Yes, significantly, at the same thickness: its conductivity is about four times lower. But cork trivets are sold at half the thickness of wooden ones, which narrows the difference, and they deform under a concentrated load.
Does a silicone trivet pose a health risk?
DGCCRF inspections mainly concern cookware heated in an oven and in direct contact with food. A trivet is neither heated nor in direct contact with food, so the risk of migration is structurally low. It is still best to check where the product comes from and whether it has a declaration of conformity.
Can a wooden trivet go in the dishwasher?
No. Hot water, alkaline detergents and forced drying cause the fibers to swell and then shrink, opening cracks and turning the surface grey. Wash by hand and dry immediately.
Can a wooden trivet be personalized?
Yes, engraving is possible on dense species such as oak, beech, walnut or acacia. It does not affect the item’s thermal resistance or mechanical strength, as the amount of material removed is very small compared with its thickness.
Conclusion
How do you choose a trivet? Consider thickness before material. Cork provides the best insulation per millimeter but gives way under a heavy load. Silicone withstands heat without stopping it, and its thinness makes it the least protective of the three. At 15 or 20 mm thick, solid wood offers enough thermal resistance for all household uses, the rigidity to support a full casserole, and the only repairability of the three materials. Over time, it is this last criterion—repairability—that sets it apart.
Sources cited
- Th-bât Rules, Materials Booklet, ministry responsible for construction (thermal conductivity by wood species)
- Guide to Insulating Materials, Espace Info Énergie network (expanded cork)
- AZoM / Granta Design, Silicone Rubber data sheet (conductivity and operating temperature)
- DGCCRF, Materials Intended to Come into Contact with Food
- DGCCRF, Rubber technical sheet
- National Assembly, written question No. 4071 and the government’s response, February 28, 2023
- Bois.com, Wood: Champion of Energy Efficiency
Teckou makes solid-wood kitchen and tableware accessories, crafted in Charente-Maritime. Its solid-wood trivets come in acacia, oak, beech and walnut, in round or square designs, with or without engraving, and coordinate with wooden coasters and the rest of the tableware collection.
