No. Each joint tenant is required to sign documents on all major transactions involving joint property. If one of the owners is mentally disabled and incapable of handling financial matters, everything will have to wait until the probate court takes control. The court, in effect, becomes a joint owner and will continue to have a voice in managing the property until the disabled owner recovers or dies.
Does a Will avoid a Living Probate?
No. A will only takes effect at the time of your death. It has no control over events during your life.
Does a Living Trust avoid a Living Probate?
Yes. One of the most important benefits of a living trust is that it is designed to protect you while you're alive. Part of every well drafted living trust is a section setting forth your instructions in the event you become legally incapacitated. You can plan in advance for management of your affairs during sickness, disability and even old age. The trustees you pick are bound by law to follow your instruction during these difficult times. With a living trust, there will be no need for expensive "help" from the probate court, probate lawyers or conservators.