We carried out a resistograph survey at a park in Rochdale for Rochdale Borough Council in 2020. Our consultant then revisited the park to re-survey in the summer of 2022.
The equipment which our consultant used was a resistograph. The Resistograph is a probing device which is used to detect decay in trees and other items made of wood. The Resistograph is a modified drill that drives the probe into the wood at a constant speed. It measures the difference in torque (power/force) which is required to drive the probe into the wood. The softer the wood (indicating denatured/compromised wood) the less torque is required.
The results from the Resistograph readings, indicated that the posts were generally in good order. The only fairly significant anomalies noted were from the first test on Post 4. The drill generally pitched more deeply and widely than all the other tests. It is possible that the drill was extending through latent radial cracks in the wood
For safety reasons, our consultant has recommended that tests are carried out on the posts on a biennial basis (at least once every two years). It was also recommended that with reference to using the Resistograph for testing for decay, an alternative was to randomly test the poles at differing levels using tomography. This method is less invasive and should be considered as a suitable alternative to micro drilling through the poles.