It is now commonplace to include a ventilated air gap between the siding material and structural sheathing to lower the risk of wall rot. As rainscreens become more prevalent, builders are increasingly wondering: Should I use a rainscreen siding wall on my project?
Rainscreens make it possible for your exterior cladding to sit away from the building’s water-resistant barrier. This, in turn, creates an air cavity vented at both the top and bottom, protecting against potential moisture damage. Any moisture that passes by the cladding will drain away easily, and any residual moisture will evaporate quickly due to passive ventilation. Here are some things to consider when planning to install a rainscreen:
Rainscreens are generally recommended (and sometimes required by code) where 60 inches or more of rain falls annually. If you reside in an area averaging over 60 inches of rain each year, it would be wise to install a rainscreen, whether or not it is mandated by code.
- Your wall
A tall wall with a short overhang is more likely to accumulate wind-driven rain under its edges, making it vulnerable to erosion. If the wall faces a wide porch, however, it will be protected from rainfall. Thus, the type of wall you have will help determine whether or not a rainscreen is right for you.
- The rainscreen material
Choose a rainscreen material that matches the overall aesthetics and feel of your deck or home. For instance, if you have an Ipe decking, then Ipe rainscreen siding would be your best option. This way, the rainscreen will complement rather than clash with the rest of your home.
- Wall sheathing
If your walls are made of SIPs or if the OSB wall sheathing has closed-cell spray foam on the interior, you should include a rainscreen. If not, the OSB becomes vulnerable to rot.
Now that you know more about rainscreen siding, you can decide if they are the right choice for your project.