Open Joint vs. Closed Joint Cladding

Source

Not sure whether to use an open or close joint for your cladding? In this episode, the focus is on open vs. close joints being used with cladding, the types of insulation to use for each and the importance of rainscreens during building. 

More About the Show

The Build Perspectives podcast shares insider knowledge to build connections and community in the facade and cladding industry. Tim and Carolina are friends, colleagues and former coworkers who love facades and their clients, and want to share their passion and insights to attract future talent to the building industry.

In this episode, Tim and Carolina talk about rainscreens, ventilated facades and the difference between open join and closed joint cladding.

Rainscreens

A rainscreen is basically a wall outside of a wall. So you have your studs, your substrate, your sheathing, your waterproofing and then your rainscreen is applied over all of that. 

And there are several different kinds of rainscreens: drained back ventilated rainscreens and pressure equalized rainscreens and more. In this episode, we are going to talk about drained back ventilated rainscreens, as they are the most commonly used type currently. 

Rainscreens allow a few things to happen. It puts some distance between the actual facade and the wall, allowing for air movement and drainability, as well as managing dew points. This enhances the performance of the wall and wall cavity, as well as indoor air quality. 

Open vs. Closed Joint

Source

Open joint can be anything from a composite residential deck material used over a black membrane to porcelain open joint claddings to high-pressure laminates. For open joints, in essence, you can see through it to the wall behind. They can be used with metal panels, phenolics, real wood or brick. 

Close joints can be Nichiha fiber cement panels, Hardy reveal, insulated metal panels, brick, stucco and EFAs.

For open joints, you are really limited to using mineral wool insulation as it’s hydrophobic, meaning it doesn’t attract water and if it gets wet from snow or wind-driven rain, it drives immediately. But for closed joints, you have a wider range of materials you can use, such as EPS and polyiso. 

Another difference is the elevation you can use them at. Closed joints have a height limit to them, while open joints can used at a higher elevation. And you also need to consider combustibility. Open joint requires a non-combustible assembly, while closed joints can use combustible materials in some cases. 

Indoor Air Quality is tied to the dewpoint in the wall. Depending on your climate, you’ll want to put your air and water barriers in different locations. In hot climates, you want the wall to dry in. In cold climates, you want the wall to dry out. For both open and close joint systems, the indoor air quality is improved because they don’t allow mold to grow when planned out and applied correctly.

With closed joints, especially on metal panels, you have to worry about streaks around the joints. With open joints, you don’t have to worry about streaks or stains because it allows the air and water out. 

The Importance of Designing for Pressure

Water is always going to find it’s way into a building, no matter what you do. What you really need to focus on is controlling the pressure. Pressure wants to go from high to low. So you need to control the airflow in your wall. To do that, you should be using rainscreens which allow your walls to breathe.

Don’t just settle for vertical airflow, either. You need a system that allows for vertical and horizontal air movement and that can manage moisture. 

Join the Conversation

We’d love to hear your thoughts on this week’s episode! Shoot us an email at