Why wood was preserved at Herculaneum (and not Pompeii)

[guy]

 

The article below about the reopening of the House of Carbonized Furniture at Herculaneum made me wonder: Why were wooden objects preserved at Herculaneum in AD 79 (and not at Pompeii)? Pictured above and below are some of the wooden objects preserved there.

The wood did not burn because the pyroclastic surge that hit Herculaneum was not the same type that destroyed Pompeii. Instead of open-air ash fall, Herculaneum was engulfed by a 20‑meter‑deep mass of superheated pyroclastic mud. Temperatures reached ~400 °C, hot enough to carbonize wood but—critically—oxygen was almost completely absent.

At Herculaneum, when the first pyroclastic surge struck the town, it produced carbonized wood. The surge raised temperatures to around 300–500 °C, but it contained almost no oxygen. In such conditions, wood doesn’t burn; instead, it undergoes a process called carbonization. This is a chemical change that drives off volatile compounds, leaving behind a stable, charcoal-like material. Because the surge quickly buried the buildings and sealed them beneath meters of hot material, beams, doors, furniture, shelving, and even architectural panels were remarkably preserved in their original shapes, only transformed into carbon. This process accounts for the incredible preservation of many wooden objects at the site.

 

 

On the ancient shores of Herculaneum, a different preservation process took place (see the picture below). Waterlogged wood creates a very unique environment for preservation. In several parts of the site, especially where volcanic mudflows and wet deposits settled, timber was buried in saturated, oxygen-poor layers rather than being heated enough to turn into charcoal. When submerged in this special anaerobic environment, decay-causing organisms couldn't thrive, allowing the wood to stay chemically 'alive.' It kept its cellular structure, species features, and even tiny growth rings. That's why archaeologists can tell the difference between fir, cypress, and spruce at the site: the wood wasn’t burned or charred but preserved through long-term saturation.

 

Above are a boat prow painted red and a vertical winch (used to pull boats ashore), both wonderfully preserved.

Pompeii’s wood mostly burned or decayed over time, but Herculaneum’s unique circumstances—such as higher temperatures, deeper burial, and lack of oxygen—preserved the world’s largest collection of Roman wooden artifacts. You can find doors, beds, shelves, roof beams, furniture, and even carbonized scrolls there.

https://www.ansa.it/english/news/2026/07/10/herculaneums-house-of-the-carbonized-furniture-reopens-after-30-years_26911e38-10bd-434f-8f29-da719b60a565.html

 

https://the-past.com/feature/wooden-wonders-of-herculaneum/

Below is an interesting video from Darius Arya highlighting the wooden objects preserved at Herculaneum.
 

 

 

 

Edited Friday at 06:18 PM by guy

[caesar novus]

Quote

After being displayed for over a year (from 13.12.2022 to 31.12.2023) at the Royal Palace of Portici, the wooden furnishings now take up residence—on an experimental basis—at the Antiquarium, arranged to recreate two typical rooms of a Roman house, thereby restoring the original functionality of the objects.

Exhibits moved back onsite: https://ercolano.cultura.gov.it/the-wood-that-didnt-burn-at-herculaneum-at-the-archaeological-park-antiquarium-the-exhibition-on-woods-visitors-immerse-themselves-in-the-setting-of-a-domus-of-ancient-herculaneum/?lang=en 

Edited Friday at 07:47 PM by caesar novus