Above all other uses, Ipe is most often used for decking. Like other decking products, Ipe decking boards are eased on 4 edges (E4E) and surfaced on 4 sides (S4S), in order to prevent splintering and sharp edges. (Since Ipe is particularly hard, these steps are extremely important for Ipe.) Depending on a customer’s installation method of choice, we may need to provide the added step of routing a groove for clip fasteners; but that would be the last “finishing” step we’d take before shipping the Ipe decking boards to your job site.
You can expect your Ipe decking to have been air-dried to a moisture level of about 18% in South America before being milled into decking boards. And that’s exactly the moisture level you want in a decking board in order to achieve optimal stability. By maintaining a higher percentage of moisture, your Ipe decking boards will be resilient to temperature swings as well as exposure to sun and rain.
Occasionally, we have requests for Ipe in other forms besides decking lumber. Kiln-dried Ipe and rough sawn Ipe are certainly not as popular as Ipe decking, but they are still products we carry. These products are intended for interior use, and as such, they’re kiln dried to moisture levels between 6% and 8%. We sell some of it rough sawn, while we mill others at our own in-house millworks. While originating from the same trees as your Ipe decking boards, these products are dramatically different from Ipe products intended for exterior use.
Just to muddy the waters a little more, we thought you’d like to know that we also carry kiln-dried Ipe decking. Essentially the same product as air-dried Ipe decking, kiln-dried Ipe decking can be equally acceptable for use in a dry climate. The basic difference between air-dried Ipe decking and kiln-dried Ipe decking is not moisture level, but time frame. Unlike kiln-dried lumber intended for interior use, which is dried to 6-8% moisture content, Ipe decking is often kiln dried to the same moisture levels as the levels to which it would have otherwise been air dried: 10-18%. Kiln-drying is often preferred, though, simply because it just takes less time. Kiln-drying to this level allows for eliminating free water without hardening cell walls or banishing bound water. (If cell walls of the wood are hardened, the wood becomes resistant to change, often leading to catastrophic results.)
So when it comes to choosing between kiln-dried Ipe decking and air-dried Ipe decking, it’s really a moot point; a better question to ask would be how to install your Ipe decking (however it’s been dried) in consideration of the unique environmental challenges your deck presents with factors like direct sunlight and seasonal shifts. Check out Part 2, where we’ll explore those issues in more detail.