Resistograph testing is an advanced tree risk analysis procedure that is invasive. The device uses a very small but long drill bit (20 inches). As the drill enters the wood it measures the resistance it encounters as it passes through hard (healthy) wood (=high resistance) and into soft (decayed) wood (=low resistance), or hollow areas (=no resistance) in the trunk.
We are still working on this page. If you’d like to discuss resistograph testing with us, please contact us.