APA – The Engineered Wood Association has a lot of useful information for builders in their website, and here we will share a very important tip: how to choose your panels for soffit applications.
Quality APA panels are a great alternative to other materials used in soffit applications. There is a variety of APA face grades from which to choose. Selecting the appropriate panel depends primarily on whether the soffit is open or closed.
For appearance purposes in open soffit construction, you have to provide adequate blocking, tongue-and-groove edges, or other edge support such as panel clips. Minimum capacities are at least 30 psf live load, plus 10 psf dead load.
For open soffit construction (figure 1), panels designated Exposure 1 may be used.
Exterior panels should be used for closed soffits (Figure 2).
In open and closed soffit construction where Exposure 1 sheathing is used for roof decking, you have to protect panel edges against direct exposure to the weather with fascia trim.
Finishing. Although unsanded and touch-sanded grades of plywood are often used for soffits, optimum appearance and finish performance is achieved by using panels with Medium Density Overlay (MDO), or textured (such as APA 303 Siding) or sanded A-grade faces. Top-quality acrylic latex house paint systems perform best and are the only systems recommended for A-grade faces.
You can find more information in the APA website: www.apawood.org/