General requirements

074 PRODUCTS
0741 GENERAL

The types of products indicated hereunder are the minimum recommended types of materials to obtain the required standard of work. The Engineer may use substitute materials of equivalent or higher standards subject to approval. Timber, posts and boards to be used for carpentry and joinery shall be of the highest quality of the selected type and obtained from sources approved by the Engineer.

Timber and posts susceptible to attack by timber destroying fungi, insects, borers and decay shall be treated with suitable preservatives prior to use. Timber & posts coming in contact with earth, weather or not requiring treatment shall be treated with wood preservatives.
The preservatives and methods of application shall be approved by the Engineer before such application is started.
The surfaces of treated timber, that have been cut or machined shall before assembly, be coated with three coats of wood preservative approved by the Engineer.

Timber and posts requiring treatment shall be pealed, sawn and seasoned to the required standards prior to the application of treatment.

Timber shall be treated by pressure impregnating, dipping, brush application or spraying depending upon the requirement of the treatment of the timber selected.
Timber and posts required to be treated, but not requiring pressure impregnating shall be treated with three coats of brush applied or sprayed in external treatment with preservatives approved by the Engineer. Timber and posts may alternately be dipped in the preservative for sufficient time that would produce equal effect as the three coats of brush or spray application of the preservative.
Pressure impregnated timber and posts shall be treated with preservatives and treatment methods approved by the Engineer at a pressure of not less than 10 Atmospheres and in accordance with the chemical manufacturers instructions.
Timber and posts shall be seasoned to a moisture content of not more than 20% for carpentry. Timber for joinery shall be seasoned to a moisture content of not more than 12%. Treated and untreated timber ready for use shall be free from live borer, beetle or other insect attack.
Measures necessary to prevent further insect attack of timber and posts shall be taken, once the timber is delivered.
Timber and posts, whether already approved for use or used, shall be removed and replaced at the contractor’s costs, if indications of their being attacked is evident.