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Grading - Ipe Hardwood Decking

Grading Document

Species: Ipe (Tabebuia spp)
Grade: FAS
Grading body: National Hardwood Lumber Association (NHLA)
Reference: Paragraphs 53 – 63 ‘Rules for the Measurement & Inspection of Hardwood & Cypress’

The purpose of this document is to provide a detailed, factual and accurate description of the material along with the officially published grade description where applicable.

It goes without saying that reading this description is no substitute for seeing the actual material.  We are always happy to send out hand samples, but they have very limited use in determining the overall quality - it is impossible to cram every feature and characteristic that you might encounter in a delivery of timber on a single 6” sample.  For this reason we encourage you to visit our premises and take a closer at the product before you buy. 


What is a timber grade?

The grading of timber can be defined as the sorting of wood sawn from a log into different qualities relating to classifications for appearance, end use or strength. The practice is essential to maintain consistency and to ensure reliability from order to order.

A timber grade is simply a minimum standard describing the extent and limitations of the characteristics permitted in a piece of timber depending on its end use.

Grading is explained in further detail in our document – ‘The Grading of Timber’


Ipe FAS Grade

There is no official standardised grading system for Ipe, however manufacturers generally adhere to the internationally recognised National Hardwood Lumber Association (NHLA) grading system.  The standard quality of Ipe commonly available throughout Europe is known as FAS grade.  It is also known and described by some suppliers as ‘First and Seconds’, ‘Prime Grade’, ‘No. 1 Grade’, ‘First Quality’,  ‘First Grade’ and ‘A Grade’. 

The actual grading rules as they appear in the aforementioned publication are set out below, however you will probably find our own description to be more useful and a more accurate representation of the actual product supplied by Silva Timber.  This is because the grading rules describe the minimum standards for the grade.


General Appearance

Ipe decking can sometimes initially appear dirty, display sticker marks and occasional water marks.  These are unavoidable effects of the production and drying process and are not considered to be defects.  Surface markings that appear on the boards are usually superficial and therefore easily removed as part of the normal installation and finishing procedure.  They will have no detrimental effect to the finished project.  If you opt to leave the boards to weather naturally, then any markings that are present will disappear quickly as the wood turns grey.  


Silva’s FAS grade air dried Ipe decking is of an exceptional quality standard.  Close examination of 154 boards at 2.44 m in length revealed that all boards with the exception of one contained within the pack were 100% usable (one had minor damage on one edge close to the end which could be trimmed off).

We found that all boards in the pack were straight or very close to straight.  There was no twisting or severe bowing.  Bear in mind that the longer the board the greater the tendency for it to be slightly bowed.  Slight bowing is not considered to be a defect.  A Bowrench® or similar tool can be used to straighten a bowed board single handed as it is installed.   

Slight end check can usually be expected with hardwood decking; however there was almost none in the pack we examined and certainly none of any significance that would require trimming.

The pack we examined did exhibit some dusty mould growth on the surface of the boards in between some of the layers.  This is a result of condensation after having spent several weeks in sealed shipping container.  If dry mould is present it can simply be wiped off and will leave no trace on the boards, nor will it have any detrimental effect to the boards or the finished project.  


In the pack we examined we found that virtually all the boards were entirely free of knots.  Of the 154 boards we found four with one or two very tiny knots.  You would need to look hard to find them as they were live grown in knots and only about 5mm in diameter. 


Very occasional small splits should be anticipated; however we encountered none in the pack we examined.


Silva’s FAS grade Ipe decking contains boards with fine, mostly straight grain with occasional patches of irregular patterned grain.   

In the pack we examined there were a few small patches of raised grain, usually around a burl which is a swirling grain pattern.  These are easily sanded smooth.

Surface Markings

As mentioned above Ipe decking can display sticker marks across the boards from the air drying process, occasional water marks, dust, dirt and even mould on occasion.  Any markings initially present are superficial and will be removed as part of the normal finishing process or will disappear as the deck turns grey if the wood is left exposed to ‘weather’.

Cut Outs

The FAS grading rules allow a range of boards that yield between 83⅓% (10⁄12ths) and 100% clear cuttings.  The size of these clear cuttings will depend on the length of the board.  Both faces must meet the minimum standard.

The reality is that with Silva Ipe decking, you are likely to encounter very few (if any) boards that require sections cutting out or ends trimming.  Any cutting or trimming undertaken during the installation process will be absorbed in the normal cutting and wastage allowance.

Colour Variation

As with any natural wood product you should expect colour variation both between boards and within individual boards.  With Ipe the colour range exhibited is within a palette of brown tones that blend together and appear ‘as one’ when viewed in the context of the finished project.


This particular pack was randomly selected and we know it to be representative of Silva Ipe decking.  The quality of raw material that we receive from our supplier is consistent from one shipment to the next, so we are confident that the material you receive will be of a quality similar to the material described above and shown in the video.  That said, please bear in mind that the next pack we could have chosen may have had more imperfections or it may have had fewer imperfections.

You are likely to generate some wastage when using this product, but by planning your cuts prior to installation this will be minimal. 

In summary Silva Ipe decking is produced to industry standard from consistently high quality raw material that exceeds the NHLA grading rules for FAS grade.  Although some boards may initially display some superficial surface markings, they will be removed as the boards are prepared for finishing.  This decking product is of a very high standard with few natural irregularities.  As such it is suitable for prestigious residential and commercial projects.  To get the very best from Silva Ipe decking it is strongly recommended that our installation guidelines are followed closely.

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