Woods to Know: Ipe - Canadian Woodworking Magazine

Woods to Know: Ipe

Ipe (Handroanthus spp.)

Wood is prized as a building material due to its beauty, structural characteristics, and availability. Among all the woods commonly used, Ipe is a true specialist. Its outstanding weathering properties make it the premium wood for exterior projects. 
 
Species of Ipe grow from Central America to Northern Argentina and Chile where they are prevalent as ornamental trees producing beautiful flowers. Other species have compounds in their bark that are used for medicinal purposes. However, this article will examine the species found in the Amazon basin, often referred to as Brazilian Walnut, which are logged to produce lumber.

WTK_ipe
 
Most of the trees logged for commercial timber production come from Brazil. Their average height is 100 feet with 2-3 foot diameters. Exceptional trees can approach 140 feet in height and diameters of 6 feet. Ipe grows in low densities; consequently, large areas of forest must be harvested to produce commercially viable amounts of lumber. Fortunately, the tree is easily cultivated and lumber from plantations is available, helping to reduce pressure on the natural stocks. 
 
The wood is very hard and dense. It is oily giving it a natural resistance to termites and other insect pests. Combining the high density, hardness, and decay resistance yields a wood that is extremely durable with outstanding weathering properties. The famous Coney Island boardwalk utilized Ipe. It lasted 25 years before replacement was necessary – a great accomplishment given the extensive pedestrian traffic and the salt-water environment it was exposed to.  
 
The heartwood ranges from an olive brown to a dark brown, often with brown / black stripes. Yellow deposits are often found in the pores. The texture of the wood is medium to fine. It is usually straight grained but can be irregular and interlocked. The sapwood tends to a distinct pale white. 
 
Ipe is difficult to work with, dulling cutting edges quickly. Screw holes must be predrilled. The oil content combined with its high density make gluing difficult. It does not take a painted finish and the yellow deposits make finishing difficult. It turns well but irregular grain can tear when the wood is being surfaced.

WTK_ipe-endgrain
End grain: Ipe
 
While these characteristics can limit its use in cabinetry and furniture, Ipe excels as exterior decking and siding. Kiln dried, it can be used as interior flooring. With proper installation and maintenance an Ipe deck could last up to 50 years. Ipe for decking is available in milled nominal sizes with eased edges  Components for stairs and railings are very common and manufacturers have developed various types of fasteners for use with Ipe. When used for exterior applications it is usually air-dried. Since it can season very quickly, Ipe can surface and end check if exposed to direct sunlight before it has a chance to acclimate with local conditions. Kiln dried Ipe is available, but its suitability for interior projects must be balanced with it other characteristics (density, hardness, etc.). 
 
Initially, Ipe can be expensive. But given its long service life, it can be a bargain over the long run. Demand for Ipe is high and concerns regarding over-harvesting and illegal cutting are justified. Woodworkers are advised to use wood sourced from plantations or from wood harvested by certified suppliers. Buying responsibly can help guarantee supplies of this wood for future woodworkers. Some authorities have called Ipe a wood of extremes: extremely dense, hard, and so forth. While this may limit Ipe primarily to exterior applications, woodworkers should look beyond its price and ask: which wood would you like to see on your deck in 25 years?
 
 
Average Dried Weight69 lbs/ft³A measure of its weight at 12% moisture and an ambient temperature of 70°F.
Specific Gravity1.10A measure of the ratio of its density compared to water (at 12% MC)
ShrinkageRadial: 5.9%,
Tangential: 7.2%,
Volumetric: 12.4%
Radial (the amount of crosswise shrinkage);
Tangential (the amount of lengthwise shrinkage);
Volumetric (the total amount of shrinkage.)
T/R Ratio1.2A measure of the uniformity of tangential to radial shrinkage.
Janka Hardness3,510 lbfA measure of resistance to denting and abrasion.
Crushing Strength13,600 lbf/in²A measure of compression strength parallel to the grain.
Colour
Heartwood is olive brown to a dark brown often with dark stripes. Yellow pore deposits are common. Sapwood is a distinct pale white. 
Grain
Usually straight but can be irregular and interlocked. 
TextureMedium to fine texture.
Workability
Difficult to work. Tools can be dulled by this dense wood. Tearout can occur on interlocked grain. Difficult to glue and finish.  Can be an allergen  causing skin and respiratory problems. 
Uses
Outdoor projects
Price$5.25/bf 4/4, 6" width
$10.50/bf 8/4, 6" width
 
  
Photos and Specifications Courtesy of: The Wood Database