Ipe — Density, Movement, Workability & Cost

Drop a scrap of ipe (Handroanthus spp.) in a bucket of water and it sinks — a specific gravity of 1.05 means it's genuinely denser than water itself, which puts it in a small club of commercial woods where that party trick actually works. That same density is why a deck screw driven straight into ipe without a pilot hole will shear its own head off before it seats: pre-drilling here isn't a best practice, it's a structural requirement.

The hardest wood most homeowners will ever touch

At 65.5 lb/ft³ and 3,490 lbf on the Janka scale, ipe is more than twice as hard as African padauk and over three times harder than teak, making it one of the hardest woods in regular construction use anywhere in the world. Carbide tooling is not optional, and even carbide dulls faster on ipe than on most hardwoods — budget real sharpening time into any project of scale. The fine yellow powder that comes off it in the pores is lapachol, and it turns green on contact with an alkaline surface, which incidentally makes it a quick field test if you're not certain what species a mystery deck board actually is.

The most stable movement figure among the dense exotics on this site

A tangential:radial ratio of 1.2 is one of the best-behaved figures in this entire species list, better than genuine mahogany's 1.4 and dramatically better than teak's 2.3 despite ipe being roughly one and a half times denser than teak. An actual-dimension deck board, 5.5" wide, moving from a wet-season 18% moisture content down to a dry-season 12% MC — a realistic outdoor swing, larger than the indoor figures used elsewhere on this site — contracts about 0.088" (2.2mm) across its width, computed from ipe's own 8% tangential shrinkage figure. That combination of very low ratio and moderate absolute movement is exactly why ipe decking has a reputation for staying flat and gap-consistent for decades where a less-behaved species would cup or crack. Run your own board width and seasonal swing on the wood movement calculator. A 12-foot length of that same 1"x5.5" actual-dimension deck board weighs about 30 lb — check other lengths on the wood weight calculator.

Gluing doesn't really work here — plan for fasteners instead

Ipe's combination of extreme density and natural oil content makes glue joints unreliable regardless of adhesive choice; mechanical fastening — hidden deck clips, stainless screws in pre-drilled and countersunk holes, or through-bolting for structural connections — is the honest, standard answer rather than a workaround. Film finishes will not stay on it outdoors under any circumstances worth the labour; a penetrating oil reapplied annually keeps the honey-brown colour, or the board can simply be left to silver, which does no harm to its already exceptional durability.

Durability that outlasts most decks built around it

Rated exceptionally durable, with a service life of 25 years or more in direct ground contact and strong resistance to both termites and marine borers, ipe frequently outlives the fasteners and substructure holding a deck together, which is a genuine maintenance consideration when specifying it. That durability, combined with a roughly $16-per-board-foot price, is the core of ipe's sales pitch against cheaper pressure-treated softwood decking: a much higher upfront cost against a much longer service interval.

Sourcing has gotten more complicated, and it matters for decking specifically

Since 25 November 2024, ipe sits in CITES Appendix II alongside the related genera Roseodendron and Tabebuia, under annotation #17 — checked here against the appendices valid from 5 March 2026, post-CoP20. That annotation reaches machined and transformed wood, so pre-milled deck boards need permits the same as raw logs, not just rough lumber; this is a meaningfully different situation than a buyer researching ipe a few years ago would have found. Illegal logging exposure in Brazil is the other documented sourcing risk, separate from the CITES paperwork question — ask any supplier for chain-of-custody documentation, not just a CITES permit number.

Where it's used, and the safety detail that catches people off guard

Decking and boardwalks, exterior cladding, outdoor furniture, flooring and tool handles are the five uses ipe shows up in most, decking dominating by a wide margin. The lapachol dust is a genuinely reactive irritant — dermatitis, headaches, asthma and even reported disturbance of vision are documented in workers who cut a lot of it without protection, making ipe one of the more reactive decking timbers on the market. A full-face respirator and good dust extraction matter more here than on almost any other species on this site.

Common questions about ipe

Can I use standard deck screws on ipe, or do I need something specific? Standard carbon-steel screws will corrode and often shear in ipe's dense, tannin-rich wood; stainless steel fasteners and a properly sized pilot hole are close to mandatory, and many installers use hidden clip systems specifically to avoid face-screwing into it at all.

Why did my "ipe" deck board turn green when I splashed cleaner on it? That's the lapachol reacting with an alkaline cleaner — it's a genuine, harmless identification reaction rather than a defect, though it can look alarming the first time it happens; a mild, pH-neutral deck cleaner avoids triggering it.

Is the new CITES listing going to make ipe decking unaffordable? It adds real permitting overhead and paperwork cost through the supply chain rather than banning the trade outright, so expect gradual price and lead-time pressure over the coming years rather than a sudden unavailability — buying from an established, documented supplier is the practical response.

Ipe's own genus was reclassified from Tabebuia to Handroanthus after this page's FPL shrinkage source was published, so older references may still list the old name; CITES status is confirmed current against the appendices valid from 5 March 2026, post-CoP20.