What is quebracho?
Quebracho is the Spanish name for several South American tree species with exceptionally hard, heavy wood. The name comes from quebrar hacha: axe-breaker. The timber has long been used for heavy construction, posts and railway sleepers, and the red species is a major source of tannin.
Species
| Name | Botanical | Feature |
|---|---|---|
| Quebracho colorado (red) | Schinopsis lorentzii and Schinopsis balansae | Reddish brown, very rich in tannin |
| Quebracho blanco (white) | Aspidosperma quebracho-blanco | Paler, from a different plant family |
The trees grow in the dry forests of the Gran Chaco, mainly in Argentina, Paraguay and Bolivia.
Properties of quebracho colorado
- Very heavy: around 1,200 kg/m³ on average when dried. It is denser than water and sinks.
- Extremely hard: one of the hardest commercial timbers.
- Very durable: good resistance to fungi and insects, partly thanks to its high tannin content.
- Difficult to work: high cutting resistance, blunts tools quickly, dries slowly and tends to check and warp.
Uses
- Railway sleepers (ties)
- Posts, fence posts and formerly telegraph poles
- Heavy structural timbers, bridge members and wood paving blocks
- Tannin extract for leather tanning
- When exported, also furniture, turnery and carving
Practical tips
- Always pre-drill. Screws or nails without pilot holes snap or split the wood. Use stainless steel fixings; tannin reacts with ordinary steel and causes black staining.
- Use carbide or diamond tooling and expect faster wear.
- Reclaimed sleepers: check whether they have been treated with creosote. In the EU, creosote-treated wood may not be used in gardens, playgrounds or places with frequent skin contact, and similar restrictions apply in the UK.
- Sourcing: the Chaco forests are under pressure from deforestation. Ask for legal, preferably FSC-certified timber.
- Tannin staining: fresh timber can bleed brown run-off onto concrete or stone below it when it rains.
Related terms
- Hardwood
- Durability class
- Exterior durability
- Pressure-treated wood
- Douglas fir wood
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