Goncalo Alves — Density, Movement, Workability & Cost

Sold in the US as tigerwood for its irregular dark streaks over an orange-brown ground, goncalo alves (Astronium graveolens) has one genuinely frustrating trait for anyone trying to match boards for a project: the streaking pattern is unpredictable from board to board, even within the same log, so buying enough matched material for a large panel means over-buying and sorting rather than trusting a supplier's description alone.

Hard, dense, and unusually smooth straight off the cutter

At 57 lb/ft³ and 2,170 lbf on the Janka scale, goncalo alves is hard and dense, yet it's one of the few dense exotics that polishes to an exceptionally smooth surface almost directly off the cutter, needing comparatively little abrasive work to reach a fine finish. Interlocked areas still tear under a hand plane, so a scraper handles those sections better than persisting with an edge tool.

Movement, and a flooring-board weight

Radial shrinkage of 4% against a tangential figure of 7.6% gives a 1.9 ratio, just under this site's movement-prone threshold — a real number on flooring stock, the use its 2,170 lbf hardness suits it for. A 6"-wide strip loses about 0.076" (1.9mm) across the width on a swing from 11% down to a dry 6% moisture content; check other widths on the wood movement calculator. That same board, 3/4" thick and 40" long, weighs about 5.9 lb at goncalo alves' milled density — the wood weight calculator covers other sizes.

Gluing an oily surface, and a colour shift worth flagging

A fresh cut bonds well; an older, oily surface benefits from a wipe before gluing to get a reliable joint. It takes a high natural polish and darkens with light exposure over time, a shift that mutes the dramatic dark-streak contrast somewhat — worth mentioning to a client up front, similar to the colour-shift conversation that matters with canarywood or jatoba.

Durability, cost, and a family connection worth knowing

The heartwood is very durable and insect resistant, priced at roughly $20 per board foot — this site's premium tier. Flooring, furniture, turnery, knife handles, and veneer round out its markets. One genuinely useful caution: goncalo alves is in the Anacardiaceae family — the same family as poison ivy — and its dust is a recorded irritant that can cause dermatitis in sensitised individuals, worth knowing even though reactions are less universal than with true poison ivy contact.

Its place among the "tigerwood" and streaked exotics

Where zebrawood's stripe only appears on a quartersawn face, goncalo alves' streaking shows up regardless of how the board is cut, which makes sourcing marginally more forgiving — a buyer isn't dependent on getting the sawing orientation right, just on finding boards with figure they like from what's actually in stock.

What people actually ask about goncalo alves

Does "tigerwood" ever refer to a different species than goncalo alves in some markets? Occasionally — a handful of other dark-streaked exotic hardwoods have been marketed under similar tiger-striped trade names regionally, which is exactly why a buyer sourcing internationally should ask for the botanical name rather than assuming every "tigerwood" listing is the same tree.

How much extra stock should a buyer order to account for goncalo alves' unpredictable streaking on a large panel? Order noticeably more than the calculated board footage requires and expect to sort through it — exactly how much extra is worth budgeting depends on how uniform the finished panel needs to look and how much variation the supplier's current pull of boards happens to carry, so it's worth asking the supplier directly rather than assuming a fixed margin covers every order.

Does a dust mask alone handle the poison-ivy-family risk, or does goncalo alves need full protective clothing like true poison ivy exposure would? A dust mask and normal shop ventilation are sufficient for most people — the reaction is a dermatitis risk from skin contact with dust and sap residue, not an airborne systemic hazard, so long sleeves and gloves during heavy sanding cover the realistic exposure route for anyone with known sensitivity.

Is goncalo alves hard enough to use for flooring in a high-traffic area? Yes — its 2,170 lbf Janka rating comfortably exceeds red oak and most domestic flooring species, which is exactly why it's marketed as tigerwood specifically for flooring and stair treads where wear resistance matters as much as figure.

Goncalo alves' shrinkage numbers trace to Table 4-4 of the USDA Forest Products Laboratory's Wood Handbook (FPL-GTR-190, 2010); density and Janka hardness are The Wood Database's own 12%-moisture-content figures.