Bottom line: cumaru and Ipe are close enough on hardness and decay resistance that neither wins the argument on strength. The differences that actually decide a project are movement — cumaru moves slightly less evenly, so gapping and fastening discipline matter more — paperwork, since the whole genus is now CITES-controlled, and supply, because availability must be confirmed for the actual batch. The CDS cumaru collection had no listed products in September 2026. Ask about sourcing before committing to a design, or compare its listed wood alternatives.
Cumaru, Ipe or composite
Most people arriving at this page are really choosing between three things, not researching a species. Here is the honest version.
| What to compare | Cumaru | Ipe | Capped composite |
|---|---|---|---|
| Hardness and density | Very hard and dense — effectively a tie with Ipe | Very hard and dense | Far softer; performance comes from the cap, not the core |
| Movement | Slightly less even than Ipe; gapping and acclimation matter | The most dimensionally even of the two hardwoods | Expands and contracts along its length; the brand publishes the rules |
| If you do nothing | Weathers to silver-grey and keeps performing | Weathers to silver-grey and keeps performing | Keeps its colour; needs washing, never coating |
| Keeping the original colour | Re-oil on the product's interval — a recurring job | Same | Not applicable, and coating it can void the warranty |
| Sourcing questions | CITES Appendix II; genus-wide listing; confirm a documented supply | CITES Appendix II; identify the botanical species and origin | Brand, collection and warranty document rather than species |
| Installation | Pre-drilling, stainless, end sealing, carbide blades, heavy boards | Identical demands | Follow the brand's span, gapping and fastener rules |
| Where it goes wrong | Wrong fasteners, no pre-drilling, unsealed cuts, tight gaps | Same, plus paying hardwood prices for a poorly detailed frame | Coating it, ignoring gapping, or buying on price alone |
Choose cumaru if you want a dense tropical hardwood, you accept the maintenance rhythm, and you can secure a supply you are comfortable with. Choose Ipe if you want the same look from a species currently listed by CDS, after comparing the supplied grade and drying. Choose composite if the maintenance rhythm is the thing you are trying to avoid. All the material families sit side by side on our decking materials hub.
What cumaru actually is
Cumaru is a timber trade name, not a single tree. It covers wood from the genus Dipteryx, a group of large Central and South American hardwoods. The USDA Forest Products Laboratory's tech sheet describes the best-known species, Dipteryx odorata, as a tree reaching 160 ft with trunks to 40 in., growing in the Guianas, Venezuela, Colombia and the Amazon region of Brazil.
You will meet the same wood under several names. FPL records Almendro in Costa Rica and Panama and Sarrapia in Venezuela and Colombia; the tree is also the source of the tonka bean. In Canadian and American selling it is usually labelled Brazilian teak or Southern chestnut — neither of which it is (see common questions).
What the wood looks like is well documented. FPL records fresh heartwood as reddish brown or purplish brown with lighter yellowish or purplish streaks, which on exposure settles to a uniform light brown or yellowish brown. The texture is fine, the grain interlocked, and the surface has a distinctly waxy or oily feel. The Wood Database adds a faint vanilla or cinnamon smell when the wood is being cut — a small detail, but a genuine identifier on site.
Density, hardness and durability: what the sources say
Cumaru is a genuinely heavy, hard, decay-resistant wood, and the published figures back that up without needing any embellishment. Here they are alongside Ipe, drawn from the same references so the comparison is like for like.
| Property | Cumaru (Dipteryx spp.) | Ipe (Handroanthus serratifolius) |
|---|---|---|
| Density at 12% moisture | 1,085 kg/m³ (Wood Database); 1,070 kg/m³ (CIRAD Tropix) | 1,050 kg/m³ (Wood Database) |
| Janka hardness | 3,330 lbf (Wood Database); 3,540 lb (USDA FPL) | 3,490 lbf (Wood Database) |
| Decay resistance | Very durable; Class 1 in the CIRAD data, and FPL rates it very durable against both brown-rot and white-rot fungi | Rated very durable with excellent insect resistance |
| Shrinkage, radial / tangential | 5.3% / 7.7%, a T/R ratio of 1.5 (Wood Database) | 5.5% / 7.1%, a T/R ratio of 1.3 (Wood Database) |
| Conservation status | CITES Appendix II; D. odorata is not on the IUCN Red List (data deficient) | CITES Appendix II; H. serratifolius is IUCN-listed as endangered |
The hardness gap is not a decision. Depending on which reference you read, cumaru is marginally softer or marginally harder than Ipe. Both sit in the same very-hard band, far above cedar or pressure-treated pine, and both are harder than a homeowner will ever notice underfoot. Other commercially traded hardwoods, including massaranduba and lignum vitae, test harder than either. Hardness alone should not decide the material.
The movement figure is a decision. Cumaru's tangential-to-radial shrinkage ratio of 1.5 is higher than Ipe's 1.3, which means it shrinks less evenly across the board as it dries. FPL puts it plainly: cumaru is "easy to air-season with a slight tendency to check and with moderate warping." That is not a reason to avoid the species — it is the reason the acclimation, gapping and fastening rules further down this page are not optional.
Durability is not a lifespan guarantee. A species rating cannot promise how long a particular deck will last. Service life depends on detailing — drainage, ventilation, flashing, end sealing — at least as much as by species. What the references do support is the durability rating: very durable heartwood with, in FPL's words, "excellent weathering characteristics." Worth knowing alongside that: FPL records that preservative "absorption and penetration of treating solutions … are inadequate" in the heartwood, so a poorly detailed deck cannot be rescued with a treatment later, and CIRAD notes cumaru cannot be used in marine or brackish water.
Sourcing: what CITES Appendix II changed
The official CITES record, published through the Species+ database maintained by UNEP-WCMC and the CITES Secretariat, lists Dipteryx spp. in Appendix II with effect from 25 November 2024. The listing was adopted at the 19th Conference of the Parties in November 2022 with its entry into effect deliberately delayed by 24 months to let the trade adjust. It is a genus-wide listing covering Dipteryx species, so it is not something a supplier can sidestep by naming a different one.
Annotation #17 covers logs, sawn wood, veneer, plywood and transformed wood, including decking. The CITES Secretariat notification confirms the listing and scope. For Ontario purchases, ask the supplier for the species, origin and applicable trade documents.
Controlled, not banned
Expect the trade to continue under export permits from the country of export.
SourceEnvironment and Climate Change Canada administers the Canadian side.
Check the shipment
Treat shipment documents as part of the order — see what to ask a seller.
SourceAsk for the botanical name, country of origin and applicable export or re-export documentation.
Ipe also needs paperwork
Ipe went onto Appendix II on the same date. The Ipe guide covers the same questions for that species.
SourceSpecies+ (UNEP-WCMC and CITES Secretariat).
What to ask a seller
Botanical name
Get “cumaru” or “Dipteryx spp.” on the quote, not “Brazilian teak” alone.
WhyA seller who cannot name the genus cannot say what is CITES-controlled either.
Shipment documents
Ask how post-listing material was documented — a normal supply question a real importer can answer.
Grade and drying
Get clear vs select grade and air-dried vs kiln-dried in writing.
WhyGrade sets the knot allowance; drying sets how much the boards move once down.
Certification
If FSC or equivalent matters to you, ask for the chain-of-custody documents rather than a description.
WhyWe have not verified how routinely certified cumaru reaches Ontario.
Profile
Choose grooved-edge (hidden clips) or square-edge (face screws and plugs) before ordering.
WhyIt sets the fastener order, the labour and the look; changing it after delivery is expensive.
Installation realities
Dense tropical hardwood is unforgiving of shortcuts, and the requirements are published rather than folklore. The figures below come from DeckWise's hardwood decking installation guidance, which covers cumaru alongside Ipe.
Acclimate
Rest the boards seven days where the deck will be built, stacked at least 12 in. off the ground.
SourceDeckWise
Ventilate
Keep at least 18 in. of open air under the joists, with open sides for cross-ventilation.
SourceDeckWise
Gap
Leave 3/32 in. between boards; a 6 in. board can shrink roughly 1/4 in.
SourceDeckWise. Cumaru’s higher T/R ratio is why this is not a place to eyeball it.
Pre-drill, never nail
Drill a 1/8 in. pilot hole right through the board for every fastener.
SourceDeckWise: stainless is comparatively soft, so it bends before the wood yields.
305-grade stainless only
Use 305-grade or higher stainless steel; anything else discolours the wood around the fastener.
SourceDeckWise
Seal fresh cuts
Seal every mitre, rip and trim with end-grain sealer within 24 hours.
SourceDeckWise
Plan for the tooling
Budget for carbide blades, and avoid details that depend on adhesive.
SourceWood Database: silica with a moderate blunting effect. USDA FPL: “difficult to saw and bore”, “glues poorly”.
Two consequences worth budgeting for. At roughly 1,070–1,085 kg/m³ the boards are heavy, which affects handling, delivery access and the labour hours quoted. And the framing underneath still has to be right: see our deck framing guide for the structure, and Toronto deck permits for what needs approval before any of it starts.
Care and colour
Leave it bare
Let it weather to silver-grey. Greying is a thin surface layer, not rot.
Maker noteThe heartwood is rated very durable, so oil is a colour decision, not decay protection.
Hold the brown
Re-oil on the finish maker’s interval; a shaded deck goes considerably longer than a south-facing one.
Maker noteDeckWise: one to two years for Ipe Oil. CUTEK: roughly six to twelve months for Extreme on high-exposure horizontal surfaces.
Restore in order
Clean, brighten, dry, then oil. Oil over grey, dirty boards looks patchy.
Maker noteFollow the finish product’s inspection and maintenance schedule.
Our deck oils and stains guide covers the finish decision, the Ontario application window and safe disposal in detail.
Common questions
Is cumaru the same thing as Brazilian teak?
It is the same wood, but it is not teak. Cumaru is timber from the genus Dipteryx; teak is Tectona grandis, an unrelated tree from Asia with a different density, colour and price, and chestnut is Castanea, a temperate hardwood. “Brazilian teak” and “Southern chestnut” are trade names that stuck to cumaru in North American selling, and Composite Deck Shop still files the species under “Teak (Cumaru) Decking”.
Do I need a CITES permit to buy cumaru for my deck?
An ordinary domestic purchase does not itself involve a CITES border permit, but ask the seller for the species, origin and evidence of lawful sourcing. Dipteryx entered Appendix II on 25 November 2024. If you import or export boards yourself, confirm the required export or re-export documents and any Canadian requirements with Environment and Climate Change Canada before shipping.
Can I actually buy cumaru in the GTA right now?
Composite Deck Shop's cumaru collection had no listed products in September 2026. Ask the store whether a documented supply can be obtained before specifying this wood; a collection page does not establish stock or special-order availability. For a near-term build, compare the listed alternatives in its wood decking range.
Useful sources
Species listings, manufacturer instructions and local availability all change. Re-open the linked sources and the documentation supplied with your own boards before ordering or starting work.
- USDA Forest Products Laboratory — Dipteryx odorata tech sheet: distribution, common names, colour and grain, specific gravity, Janka hardness, shrinkage, seasoning behaviour, decay resistance, treatability and working properties.
- The Wood Database — Cumaru and Ipe: density, Janka hardness, shrinkage and T/R ratio, rot resistance, workability, silica and pre-boring notes, and conservation status for both species.
- CIRAD Tropix data via My Tropical Timber: density at 12% moisture, natural durability class, use class, modulus of elasticity, stability in service, and the marine-borer limitation.
- Species+ (UNEP-WCMC and the CITES Secretariat): the Dipteryx spp. Appendix II listing effective 25 November 2024, its CoP19 origin and 24-month delay, the twelve listed species, and the text of annotation #17.
- Environment and Climate Change Canada — permits for trade in protected species: how CITES permits and border validation work on the Canadian side.
- DeckWise — hardwood decking installation and its pre-drilling guidance: acclimation, storage height, board gapping and expected shrinkage, pilot-hole size, stainless-steel grade, end sealing and ventilation.
- DeckWise — Ipe Oil and CUTEK Canada — Extreme: the re-application intervals quoted for tropical hardwood, each attributed to its own manufacturer.
- Composite Deck Shop — cumaru collection and the full wood decking range: check the current listings and ask the store about supply.