The development of accelerated test methods to evaluate the durability of framing timber

• Published in: International biodeterioration & biodegradation Vol. 94; pp. 63 - 68
• Main Authors: Singh, Tripti, Page, Dave, van der Waals, Jackie
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2014
• Subjects: Accelerated test; Decay; Durability; Formulations; Framing; Hazard class H1.2; Hazards; Leaky building; Test procedures; Timber; Wood; Wood biodeterioration; Leaky building; Wood biodeterioration; Hazard class H1.2; Decay; Accelerated test
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2014.04.029

Various accelerated decay resistance trials, including small simulated wall units, samples exposed in enclosed tanks and ‘I’ samples in stacks, have been explored and used to test the durability of treated and untreated radiata pine framing at Scion since 2001. These testing methods have been established to determine the effectiveness of commercial formulations in preventing decay in framing subjected to intermittent wetting. These are relatively short term test methods requiring a minimum of 12 months testing. Results of these tests have been used to develop suitable preservative formulations and retentions for Hazard Class H1.2 for inclusion in New Zealand Standard for Chemical Preservation of Round and Sawn Timber (NZS, 3640). In New Zealand framing hazard Class H1.2 is for timber that is protected from the weather but with a risk of wood reaching a moisture content conductive to decay. In this communication, we discuss the advantages and disadvantages of these test methods. •Various accelerated test systems have been explored to test the durability of framing timber.•Hazard class H1.2 was developed to overcome the leaky building syndrome, currently prevalent in NZ.•Framing hazard class H1.2 is for timber protected from weather but with a risk of wetting.•All the test methods showed that severe decay develops on untreated samples within 25 weeks.•“I” sample test is a preferred method due to being able to duplicate construction joints and cost.