siding to leak water, and that’s why some kind of back-of-siding drainage pathway is a great idea. Installing siding on strapping is one option, and there are plastic and mesh-type products made especially for the job. I’m getting ready to install cedar shingle siding on a project of my own right now, and I’ll be putting the shingles over a dimpled plastic drainage sheet called DELTA-DRY (888-4DELTA4). Any of these options are a sort of “plan B”, just in case of leakage. That said, most wood siding installations in Canada don’t have effective back-of-siding drainage and it’s not the end of the world. If I were the prospective buyer of your house, I wouldn’t let lack of strapping stop my purchase. Quick paint deterioration is often an indication of leakage problems, and it’s a good sign that your siding is holding up well.