Before we packed up the testing gear, we decided to look at one more detail. We repeated the experiment only this time we drove a nail through the siding before setting it into the petrie dish. We forced the square of housewrap and disk of blotter paper over the nail. End Points - What it all means As I said earlier, I am reluctant to predict field behavior from lab bench results. You can choose a product that won't.
Unprotected wood absorbs water.
Most wood siding is not backprimed. Let's stop this practice. Backprime and end coat wood siding before it is installed. A water repellent treatment is best. This one step alone will not only minimize rot, but will also prolong the service life of the exterior paint.