I broke up with my common law spouse and I have been storing…

There are no automatic division laws of common law property in Ontario, so the normal laws about abandoned property apply.

The law is that at some point you can treat the property as abandoned, and take steps to deal with it as you see fit. There is no set time limit as to when that happens, and it depends on what is reasonable in the circumstances.

Things a court would look at to determine if you waited an appropriate amount of time would be whether there was any type of advance notice provided to the owner that you plan to treat the property as abandoned if not claimed, with reasonable storage fees (if any) paid to you.

It would also matter if there are any particular costs or inconvenience to you in keeping the items, and the lower those costs or the less inconvenience that this may be, perhaps the longer a court might require before you could reasonably consider it abandoned. Here it seems that the costs and risks are actually quite significant if you are paying to have to lease a space for storage.

Also the value of the item could matter, with a higher value item probably requiring a longer time before it would be considered abandoned.

And certainly the amount of notice or warning that you give to the owner that the property will be considered abandoned and become property will be a factor. The longer the notice, or the more frequent the warnings, the more likely a court will be to find that the item was abandoned, than if you gave just one warning, or gave, say, 2 days notice that an item would be sold if not claimed.

You want to be able to document that you gave notice, such as with copies of letters or emails or so on. It may be prudent to still send one further written notice, giving the person some further final period of time to come in, pay your invoice for any storage fees (if you think this is reasonable) and pick up the items or it will be considered abandoned and become the property of you. That letter can be sent to the person where he works, as well as to his old residence.

After that if you sell you would keep the proceeds. You may want to summarize in that letter the other attempts and requests you have made to have this dealt with, and explain why this results in costs or inconvenience to you and the amount of fees to be paid should he want to pick up the items. Keep a copy of that letter in case he sues you in the future to try to recover the property or its value, as your proof that you did everything reasonably possible. Also keep any documentation regarding sale or scrap or removal of the items so you can show what it was worth, in case this person tries to claim some wildly inflated value for the property.