07/07/2014
Grading and processing

Three months ago I blogged about the felling, milling and stacking of our Western Red Cedar Trees.

Just last week I worked with 3 brilliant students from The University of East London to grade and process all of our Western Red Cedar planks.

Liz Turner from Trada joined us for a morning and ran a workshop with the students, focussing on British timber and its properties.

Liz also talked about moisture, movement, grading, fixing and designing for durability.

We also tested the moisture levels in the boards and were delighted to find that they had a moisture content of around 14 – 18% moisture, ideal for external cladding. Please refer to Trada’s fantastic cladding guide for more information.

After a day of trial and error we developed a very efficient system for cladding preparation, allowing for 3 people to process approximately 150 – 200 boards per day. The process is as follows:

1 – Board selection (instant visual grading) – temporarily remove any boards with any defects (sapwood, dead knots or substantial movement)

2 – Take first 92mm off boards with 30 degree cut on table saw and stack

3 – flip boards over and cut to 90mm – ensuring finished fascia of 80mm across the width

4 – visually grade boards to choose face

5 – measure 2.5m boards down to final board lengths (multiples of 600mm), depending on location of knots near to fixing point

6 – cut board on chop-saw and stack in trailer

All the initially excluded boards are then processed in a similar way to ensure minimal wastage.

Any offcuts are stored to use as kindling for the stove or fuel for the Biomass boiler.

Next week we will start cladding the building itself. Watch this space…

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