KILN DRIED TIMBER.

Press, Volume LXI, Issue 18408, 15 June 1925, Page 13

KILN DRIED TIMBER.

TO THE,EDITOR OT "188 KISS." .Sir, —I was..,'very' pleased to read Mr Winsor's comments on tho above sub' jeet. It "■■. is. ..somewhat surprising -thatboth Mr'Entrican, Enginoer of VFbrest products, and also the conference relating to building construction, held .in Wellington, 1924, should: advocate the kiln drying of timber. In Section 4, of Circular:l4>-1 notice that it was resolved to. recommend the Government to experiment in kiln drying, . and, almost in:the, same breath,.resolved to recommend investigations' with .regard to preservatives on. sap. timber. This/ second recommendation inclines ono to think that they .realised; the necessity for preservatives after the process < of kilii drying, as this, rather drastic method "naturally causes, the timber to become sap. , Now it has been proved ..by all experienced in the "seasoning ot"-timber, that, while.'kiln drying- may bo *< satisfactory for American, timbers, it is most decidedly, unsatisfactory when used on New Zealand timbers. ' This' is becauso American /timbers are'softer and more open in the grain, as a result of which the moisture can be drawn out, without, to any great'extent, affecting the durability and, strongth of tho. timber. New Zealand timbers, on tho other hand, being dense and . close-grained, have always depreciated • in - value through the action of Tuin drying. As Mr Winsor states, it draws out the grain, which is; tho-peculiar beauty, of New Zealand timber,-it also-takes out all the life so that the timber practically becomes sap> not nearly.so durable, and certainly riceding the application of-the preservatives the,conference advocated the use of.; This process has ahso been found to weaken the timber, making.,it very brittle." It is. quitc'safc to. say that structures built of kiln dried timbers would not. only look cheap, but also would not be so durable and strong-as constructions built of timber seasoned in a natural way.—Yours, etc. •■-"-'- 0. O'NEILL.... June I?th, 1295. . . /