Manufacture of Profiled Amabilis Fir Deckboards with Reduced Susceptibility to Surface Checking

Kenneth Cheng,Philip Evans

doi:10.3390/jmmp2010007

Abstract

Machining grooves and ridges (peaks) into the surface of wooden deckboards reduces undesirable checking that develops when “profiled” boards are exposed to the weather. We aim to develop improved profiles for amabilis fir decking to reduce its susceptibility to checking, and also to examine whether profiling influences distortion (cupping) of deckboards. We systematically varied radii of grooves and peaks, and the heights and widths of peaks in profiled deckboards, exposed them to the weather, and measured checking and cupping of boards. Profiling significantly reduced the numbers and sizes of checks in amabilis fir deckboards, but increased cupping. Profiles with narrow grooves and tall peaks were generally better at restricting checking than profiles with wide grooves and shorter peaks. Our results suggest that one of the profiles we tested would be better at restricting checking than profiles used previously to manufacture profiled decking from amabilis fir. We conclude that the surface checking of profiled amabilis fir decking can be significantly reduced by altering the geometry of surface profiles. In principal, the same approach could be used with other softwood species that have potential to capture a share of the large and important market for wood decking.

Highlights

The manufacture of decking is an important industry, and in the US alone over 3.6 billion lineal feet (1.1 billion metres) of decking valued at 7.1 billion (US) dollars is manufactured each year [1]
Our results show that profiles with narrow grooves and tall peaks were generally better at restricting checking than profiles with wide grooves and shorter peaks, and suggest that one of the rib profiles we tested would be better at restricting checking than profiles that have been used in the past to manufacture profiled decking from amabilis fir
We have demonstrated that the effectiveness of profiling at reducing surface checking of amabilis fir decking can be improved by altering the geometry of surface profiles

Summary

Introduction

The manufacture of decking is an important industry, and in the US alone over 3.6 billion lineal feet (1.1 billion metres) of decking valued at 7.1 billion (US) dollars is manufactured each year [1]. Forbe) wood, whereas the opposite was the case with southern pine (Pinus spp.) decking [13,15] These findings suggest that the dimensions of surface profiles influences their ability to reduce the checking of wooden deckboards. To test this hypothesis, we manufactured profiled decking from amabilis fir wood and systematically varied radii of grooves and peaks, and the heights and widths of peaks at the surface of deckboards. Our results show that profiles with narrow grooves and tall peaks were generally better at restricting checking than profiles with wide grooves and shorter peaks, and suggest that one of the rib profiles we tested would be better at restricting checking than profiles that have been used in the past to manufacture profiled decking from amabilis fir

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