About Red Cumaru

Red Cumaru decking is an extremely hard, tropical hardwood, with interlocking grain which makes it naturally resistant towards rot and decay. It is the perfect wood for long-life exterior projects such as decks, benches and bridges. Itís reddish-brown hue can be easily maintained or left to weather into a beautiful, silver-gray patina.


A Kiln Dried product brings more long term stability to the construction of your deck.

Uniquely beautiful and extremely durable

Easy to install.

Naturally resistant to rot and decay.

Naturally fire resistant.

Environmentally sound growth and harvesting practices.


Striking Beauty

Red Cumaru is a stunning Brazilian hardwood that provides an unmatched combination of natural strength and breathtaking beauty. Red Cumaru decking is a warm reddish-brown color, ideally suited for todayís outdoor living space. With itís natural interlocking grain, Red Cumaru is the perfect choice for your next decking or outdoor project.

Itís your choice, either apply a yearly oil finish and enjoy the natural beauty this wood has to offer, or leave it to mother nature to weather it to a striking patina gray color. Either way you will experience a decking product like no other on the market.

Natural Durability

Red Cumaru hardwood decking is naturally resistant to rot and decay. The high oil content in Red Cumaru decking makes it very resistant to the elements, allowing it to serve as an ideal hardwood for any outdoor decking project. Red Cumaru is harvested from managed growth forest projects, using the most up to date, environmentally responsible sustained yield forestry techniques.

Easy Maintenance

A wood stabilizing agent should be applied to the deck before itís exposed to sunlight. Simply keep the pieces which have not yet been installed under a tarp. Apply the sunscreen agent during or after each section is installed. A coat of a high quality finish is suggested. We suggest Messmerís UV Plus for Hardwoods Apply annually or as needed. Thatís it!

Installation Instructions

Handling and Cutting


Keep the product out of direct sunlight until ready to install and finish.


Do not construct your deck without proper ground-side ventilation.


Although Red Cumaru can be cut and machined with standard woodworking tools, a carbide tipped blade is recommended for large jobs and best results.

Finishing and Maintenance


A high quality finish is required immediately after installation. We recommend Messmerís UV Plus for Hardwoods.


For very large jobs or prolonged installation, seal each section as completed.


Yearly cleaning and resealing are required to maintain Cumaru Deck natural beauty.




Stainless steel screws are recommended but not required. Screw length should be a minimum of 1-1/2" longer than thickness of the board.


Pre-drill fastened pilot holes close to the actual screw diameter (decking board only).


A minimum of 1/8 spacing required between decking boards.


Decking boards should be attached with 2 screws at each joint.

End Sealing


After crosscutting exposed ends should be sealed with clear paraffin wax based sealer.

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Mechanical Properties

First and third sets of data based on the 2 in. Standard, the second on the 1 in. Standard.

Moisture Content

Bending Strength

Modulus of Elasticity

Maximum Crushing


19,295 psi

2,690 (1000 psi)

9,020 psi

Dry (12%)

27,270 psi

3,030 (1000 psi)

13,720 psi

Janka side hardness 2,200 lb for green material and 3,540 lb for dry. Forest Product Laboratory toughness average for green and dry material is 265 in-lbs.

Dry and Shrinkage
Generally reported to dry evenly and is only slightly prone to checking if dried properly. Some shrinkage may occur after installation.

Laboratory tests indicate the heartwood to be very durable in resistance to both brown-rot and white-rot fungi.

Working Properties
May be difficult to saw and bore where severely interlocked grain is present. Finishes to a smooth surface. It is reported that the naturally high oil content in Red Cumaru can occasionally make finishing and gluing difficult

Residential and commercial decking, boardwalks, bridges, benches and exterior construction.

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About Red Cumaru Decking
(Dipteryx odorata)

click to enlarge

Botanical Information

Trade or Common Name: Cumaru
Botanical Name: Dipteryx odorata
Geographical Location: South America, Brazil

Pcf. (varies) Green 67lbs Dried 60-64lbs avg


Hardwood Decking Warranty
Exterior Wood Inc.
ďWarrantorĒ warrants that itís Red Cumaru hardwood decking will be free of any and all manufacturing defects and warranted for a period of one year from date of purchase against excessive movement when product is installed according to installation guidelines.

A visual inspection is required by a representative of Exterior Wood, Inc. Any and all boards deemed defective shall be replaced free of charge. Warrantor shall not be liable for any installation or reinstallation cost or the natural characteristics of some wood to split, warp, cup or twist, or for any incidental or consequential damages.

Warranty applies only to original owner. Proof of purchase must be submitted upon request.

© EXTERIOR WOOD, Inc. all rights reserved.