The importance of timber sampling when assessing timber framing

James Glennon
By

James Glennon

A question I regularly get asked whilst undertaking a timber remediation project is why do we take timber samples? Quite simply, the answer is how else do you know if the timber has started to decay?

Timber decay is sometimes obvious, as seen in the examples below:

timber sampling     timber decay

However, a lot of timber decay is not quite as obvious and, at times, can’t be seen at all. Throughout my career with Kaizon, I have been involved with countless timber remediation projects and one of the things that still surprises me the most is the lack of understanding on the reasons for timber sampling.  

In one instance I will share with you below, there was a leak at an internal corner from above this photo. We obtained a timber sample to send for laboratory analysis because we wanted to be sure the extent of the decay had been captured. After we obtained the sample (but prior to the laboratory results coming back) the contractor thought he knew which areas were decayed and proceeded to apply Protim Framesaver to the boundary joist. 

timber decay

The sample obtained from the joist was tested and was found to be decayed, therefore, the boundary joist had to be replaced. Unfortunately, the time and money spent on applying Protim Framesaver to this area was wasted. It was a lesson learnt for the contractor and many others that it’s best to do some research and ensure you know the full extent of damage so you can then find the appropriate solution.  

Unlike the examples provided above, decay is not always obvious and can seriously affect the structural integrity of the timber framing if left in-situ. It is recommended that timber samples are taken not only to assess whether there is decay present in the timber framing, but also the level of treatment within the framing can be determined.

Untreated timber framing can, and will, decay significantly faster than the treated equivalent. This is why it is vital to find out if the timber present is treated or untreated.
A common question we get is, can timber sampling be expensive? The simple answer is yes, but the consequences of covering up decayed timber because the contractor thought “she’ll be right” far outweighs the cost of doing the job properly. 

If you think you may have a problem with a leaky building or have found signs of decay when remediating, don’t leave it and hope it will be ok. Get in touch for a chat and we can advise you on what we think the best next steps are.