Back-priming is the process of applying a coat of primer to wood, or siding, to prevent moisture from entering the material. Now, why don’t we just do that instead of going the long way around this? Priming does not completely protect the materials from moisture, but it is extremely important that if you oil the front of the siding, to oil the back of the siding.
Should I Back-prime?
Back-priming is great practice, but do not rely on this process alone to protect your siding from water intrusion. Moisture will still manage to penetrate the siding through minute cracks and crevices, no matter how well you think you’ve primed each and every board.
Softer woods such as cedar and pine definitely benefit with extra primer. These types of woods are more prone to water damage. Exotic hardwoods such as Advantage Rainscreen Ipe™ and Advantage Rainscreen Cumaru™ are infused with natural oils that make them less susceptible to water intrusion. Normal primers will begin to peel when applied to exotic hardwoods, and oils that would normally adhere to softer woods, will only gum up on these types of woods.
Only use approved oils on exotic hardwoods.
What if I still decide to Back-prime?
Only use approved oils and primers on exotic hardwoods, and any wood for that matter. The last thing you want is to ruin all of your siding because you didn’t use an approved oil for the type of wood in your project. Set aside enough time for the primer to dry, at least 48 hours.
Pro Installation Tip:
Sand all sides of each piece of siding. This allows you to level the board for superior adhesion of any oils and paints you decide to apply. This may seem like a tedious task, but it allows you the chance to ensure your finished surface has a smooth and linear look.
Back-priming is a process that should be well researched before installation begins. Make sure you only use approved oils and primers for the materials you are using and allow adequate time between application and installation. You want to make sure that everything is done correctly to ensure the maximum life expectancy of your siding.