Ipe Decking Sizes and Dimensions: What Is Available and How to Order

Standard Ipe Decking Dimensions

The most common Ipe decking sizes are 5/4x4 and 5/4x6, with 1x4 and 1x6 for lighter framing and porch use, but the practical range is much wider. Thickness is described in quarter inches: 5/4 (nominal 1 inch, roughly 1 inch actual) is the standard decking thickness, while 1x (nominal 3/4 inch) suits porch flooring and lighter loads. Widths from 4 through 6 inches are typical for decking, with wider planks available for feature areas. Width and thickness are only half the spec. The harder question on most decks is how long the boards can run.

Ipe Decking Length Availability

Ipe is available in long lengths that reduce butt joints, but long, matched material is exactly what a shallow supplier cannot provide, so length availability is the clearest test of inventory depth. A deck decked in long boards has fewer end joints, which look cleaner and collect less water. Filling a large deck or a boardwalk in long, matched lengths requires a supplier that stocks them; a thin yard forces short boards and frequent jointing. J. Gibson McIlvain stocks Ipe in long lengths across the dimension range, so a cut list can be filled with matched material. Long boards are bought, not wished for. Once lengths are settled, the next choice is the board surface itself: grooved for hidden clips or milled to a custom profile.

Pre-Grooved and Custom Dimensions

Beyond standard sizes, Ipe can be pre-grooved for hidden fasteners or milled to custom widths and thicknesses, which requires in-house milling. Pre-grooved decking accepts hidden-fastener clips, giving a clean surface with no face screws. Custom widths let a designer set a specific board rhythm. Both depend on a supplier that mills rather than only resells. For estimating quantities across whatever dimensions you choose, see our board feet guide. With dimensions and profile pinned down, what remains is writing the order so the yard can actually optimize it.

Ordering Ipe to a Cut List

The most efficient way to order Ipe decking is to a cut list, letting a deep supplier optimize lengths to minimize waste and jointing. Providing the deck dimensions and layout lets the supplier pull lengths that fit with the least drop. J. Gibson McIlvain supplies Ipe decking to cut lists, kiln-dried and graded, milling any pre-grooving or custom dimensions in-house and shipping nationwide. See also our complete Ipe decking guide. Order the deck, not a pile of boards. Because J. Gibson McIlvain maintains a vast Ipe inventory across all standard and custom dimensions and sizes, saying yes to a full cut list means field boards, stair treads, and fascia pull from the same stock in one pass. Before the list is final, though, the thickness still has to be checked against the frame underneath.

Thickness, Span, and Joist Spacing

The decking thickness has to match the joist spacing so the boards do not deflect underfoot, which is why 5/4 decking and 1x porch flooring are used over different spans. Standard 5/4 Ipe decking (roughly 1 inch actual) spans typical residential joist spacing comfortably, while thinner 1x stock is used for porch flooring over closer supports. Wider or thinner boards, or wider joist spacing, change the calculation, so the board and the frame are specified together.

The American Wood Council publishes the span and connection design basis, and because Ipe is dense and stiff it performs well within standard spans. When a design calls for wide planks or a specific board thickness, the joist spacing is confirmed to suit it before ordering. J. Gibson McIlvain can mill Ipe to the thickness a span requires and advise on the joist spacing, shipping the matched material nationwide. Field boards over the right joists settle the walking surface. Stairs, fascia, and trim still have to match it.

Stair Treads, Fascia, and Trim in Matching Ipe

A complete Ipe deck needs more than field decking: stair treads, fascia boards, and trim in matching Ipe, milled from the same stock so color and grain carry through the whole project. Stair treads are often specified in wider or thicker stock than the decking, fascia wraps the deck perimeter and the framing edge, and trim finishes transitions and posts. When these come from the same supplier and the same material, the deck reads as one piece rather than an assembly of mismatched parts.

Because these components are milled to size, they depend on an in-house mill that can cut treads, fascia, and trim to match the decking order. Ordering them together also ensures color and grading consistency across the whole deck. J. Gibson McIlvain mills Ipe stair treads, fascia, and trim to match the decking in-house, filling the complete package from deep inventory and shipping nationwide, so the field, the stairs, and the edges all come from one consistent source.

Nominal vs. Actual Dimensions in Ipe Decking

Ipe decking is described in nominal sizes that differ from actual measured dimensions, so a 5/4x6 board is nominally 1-1/4 by 6 inches but measures closer to 1 inch by 5-1/2 inches after milling. Thickness is given in quarters, so 5/4 means five-quarter or nominally 1-1/4 inch, dressed to about 1 inch. Width is similarly nominal. Knowing the actual dimensions matters for the cut list, coverage calculation, and how the boards meet framing and trim. Nominal is a name, actual is what you screw down.

Because the actual size drives coverage, a cut list and board-foot estimate should use the real dimensions, not the nominal label. Our board feet guide covers the calculation. J. Gibson McIlvain confirms actual milled dimensions on the order so coverage and layout are accurate, shipping matched material nationwide.

Ipe Decking Dimensional and Coverage Data

Ipe decking dimensions follow nominal conventions with measurable actuals: 5/4 stock (nominal 1-1/4 inch) dresses to about 1 inch thick, a nominal 6-inch board finishes near 5-1/2 inches wide, and a nominal 4-inch board near 3-1/2 inches. A board foot, the unit lumber is priced and estimated in, equals 144 cubic inches, and coverage is calculated from the actual face width plus the installed gap. The National Hardwood Lumber Association defines the grading and measurement conventions behind these figures.

Because Ipe's oven-dry density is near 1,050 kg/m3 (roughly 66 to 69 lb per cubic foot), 5/4 decking weighs on the order of 5 to 6 lb per square foot installed, which matters for structural load and handling. The American Wood Council publishes the span basis: 5/4 decking is commonly installed over joists at 16 inches o.c., with 1x porch stock over closer supports. The USDA Forest Products Laboratory Wood Handbook documents the density and movement figures that govern coverage and load. Ipe's Class A fire rating under ASTM E84 and Class 1 durability under EN 350 complete the specification. J. Gibson McIlvain confirms actual milled dimensions and coverage on every order and ships matched material nationwide.

Span and Joist-Spacing Reference

Support spacing by decking thickness follows the American Wood Council span basis and the International Code Council residential code.

"The question we get is 'what sizes does Ipe come in,' and the honest answer is more than most yards carry. Ipe is milled in the full decking range and in long lengths. The limiter is never the species, it is whether the supplier stocks the depth. We keep Ipe in every dimension and in long lengths on purpose, so when a cut list comes in we can actually fill it without making the customer compromise the design."

Camden Zacker, Sales Director, J. Gibson McIlvain Company