Ekki Strength and Toughness

EKKI is internationally recognized as being one of the strongest and toughest timbers available in large dimensions. EKKI is included in some European standards but not in Canadian standards.

The purpose of the three tables below is to illustrate the relative strength of EKKI hardwood and its closest North American/Canadian competitor for heavy-duty exterior applications, namely Douglas Fir.

The data in the tables below show that EKKI hardwood is much stronger, tougher and resistant to abrasion than Douglas Fir. Hence much less EKKI is required to do a given job and, in abrasive applications, it lasts much longer.

TABLE 1 shows the strength values of EKKI and #1 Douglas Fir as published in German DIN 1052 and Dutch standard NEN 3582. For comparative purposes, the values for #1 Douglas Fir as published in CSA 086-94 are also shown. Units are MPa.

* The reason for the apparent disparity between these values is not known. The data in table 2 below suggest a ratio of about 5 in favor of the ekki hardwood.

Table 1, Strength values from various standards

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TABLE 2 shows the mean strength values of EKKI hardwood as in a paper published by the Imperial Institute of London. The values for Douglas Fir and Jack Pine are from "Strength and Related Properties of Woods Grown in Canada", Forintek, Ottawa, Published by Public Works and Government Services Canada, Catalogue no. FO64-21/1977. The units are inch-pounds.

* Force to imbed .444" steel ball to half its diameter

Table 2, Strength data from tests

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Table 3 contains strength data of EKKI hardwood and Douglas Fir from "The Strength Properties of Timber" by The Princess Risborough Laboratory of the Building Research Establishment. Published by MTP Construction, St. Leonard's House, Lancaster, England.

Table 3, Selected comparative strength data

NOTE. Based on the relative values for cleavage | | grain for Douglas fir and EKKI in table 2, the resistance to splitting of EKKI is estimated to be about 24.

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