Rainscreen Wood Siding 101

If you live in an area with significant rainfall each year, you’ve probably dealt with the issues that it can cause. Rotting of the wood behind the siding of a home is a common issue in areas with higher moisture levels. Like many issues, prevention is a far better alternative to correcting the problem once it’s been discovered. For this reason, it’s usually recommended – and in areas where rainfall exceeds 60-inches a year often required – that you install rainscreen behind your wood siding. A rainscreen isn’t a material or thing, it’s a system that will allow your home to breathe beneath the siding, allowing air to pass through and moisture to dry out before it can become trapped and cause problems. Rainscreens can be installed beneath any type of wood siding, although combining a rainscreen with modified wood siding like Kebony helps to increase your chances of a successful installation.

What Is a Rainscreen?

In the simplest terms, a rainscreen is a ventilation gap between your siding and your home. A waterproof barrier is usually installed over your home, with furring strips attached to the studs, which your siding is installed on in turn. Some rainscreens also contain weep holes toward the bottom of the installation to allow for water to drain out, but this is not always necessary. In some instances, a drainage mat such as Driwall Rainscreen UV may be used without furring strips. The mat encourages airflow, while its dark color helps prevent it from showing through.

Another option to consider is a rainscreen clip like that from Climate-Shield. The clip works with wood siding like Kebony, and allows for the installation of the siding in any direction - including vertically, also without the use of furring strips. Made of Marine-grade aluminum, these clips have a lasting durability that ensure the successful installation and use of the system.

The basic purpose of the rainscreen is to allow for airflow and ventilation between your home and your siding. In areas that see heavy rainfall, it’s common for moisture to become trapped behind the siding where it can’t be seen. Over time, that moisture leads to issues such as wood rot, mold and mildew, which can be expensive and difficult to deal with and repair. Therefore, a rainscreen can help to keep the area dry and prevent these kinds of issues from occurring.

When Do You Need a Rainscreen?

Not every home or every wall is going to need a rainscreen. It’s generally recommended that a rainscreen be installed on homes where the average rainfall exceeds 20-inches per year. Even then, however, there are some walls and areas on the home’s exterior that may not require a rainscreen installation.

Short walls that have wide roof overhangs, such as porch walls, are less likely to see a buildup of moisture the way that tall walls and walls that aren’t as protected will. Therefore, you may not need to install a rainscreen on every exterior wall of your home.

Other times, it’s imperative that a rainscreen be installed. One of the factors that a rainscreen deals with is the distribution of moisture into areas where it can evaporate or drain. Walls sheathed in synthetic materials or that have spray foam on the interior are much more likely to need a rainscreen than walls that are sheathed in plywood.

How Large Does the Rainscreen Gap Need to Be?

Arguably, the most important part of the rainscreen is the gap between the siding and wall. It’s this gap that allows or airflow and ventilation, as well as for drainage. It has been found that a gap a small as 1/16-inch is enough to let air circulate in this area. However, most builders use a ¼-inch gap, because the furring strips commonly used to create the gap are sized accordingly. However, you can use a deeper gap if necessary as well – ½-inch or ¾-inch gap can be used in areas of high rainfall. Larger gaps may also be necessary if the sheathing does not allow for moisture evaporation or distribution through the area.

If you are installing a rigid foam insulation over the home, your furring strips may need to be thicker as well, simply to allow for the installation of the rainscreen; a ¾-inch gap may be necessary simply to allow the installation of the strips to the home.

Pairing a Rainscreen with Modified Wood

A rainscreen is definitely beneficial for any home clad in wood siding. Wood siding is capable of absorbing water, which in turn needs to find a way to be redistributed to avoid problems such as wood rot or mold.

Pairing a rainscreen with modified wood helps the system work even better, because the modified wood is less likely to absorb and hold onto moisture. It’s also less likely to develop issues when exposed to moisture, such as rotting or mold growth. For homes that are in high rainfall areas, a rainscreen installed with modified wood siding can add double protection to the home, ensuring that the siding will not suffer from the moisture or spread that moisture and related issues to the house sheathing underneath. A smaller gap can be used, because less redistribution is required, and the system can last longer without need of repair or replacement.

Install a Rainscreen with Your Wood Siding

Installing a rainscreen with your wood siding helps to protect the home from moisture problems associated with rainfall. Pairing that rainscreen with Kebony modified wood helps to increase that protection and ensure that the installation of the siding and rainscreen will last as long as possible. Protect your home from moisture issues by installing a rainscreen beneath your wood siding to ensure your home’s longevity no matter where you live.