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A technical report published by Forintek Canada's Eastern Forest Products Laboratory titled "Strength and Related Properties of Woods Grown in Canada" indicates that Northern
White Cedar has a total volumetric shrinkage of 6.4%. This is over 15% less shrinkage than a comparable species, Western Red Cedar. In a book titled "Limit States Design of Wood
Structures" authored by F.J. Keenan, it suggests that radial checking is expected in species with:
1. high specific gravity;
2. high ratio of tangential to radial shrinkage (St/Sr);
3. low tensile strength perpendicular to the grain.
A review of this data shows that Northern White Cedar and Western Red Cedar have comparable properties, as follows:
| Species |
Specific Gravity |
St/Sr |
Tension perpendicular to the grain (p.s.i.) |
| Northern White Cedar |
0.299 |
2.12 |
240 |
| Western Red Cedar |
0.312 |
2.14 |
230 |
Based on these properties as the main factors which will effect radial checking, boards of Northern White Cedar and Western Red Cedar will perform equally in exterior inservice conditions.
In summary, good dimensional stability combined with excellent natural decay resistance will ensure that pet houses built of Northern White Cedar will provide the durability required inservice
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