There are many factors in making a decision for the best size or depth of a beam or I-joist. The first thing to verify is availability of the product. Availability of joist series and depths varies based upon your location. Next determine if you have height or on-center spacing restrictions. It’s always best to compare the overall floor system cost as compared to the lineal foot cost of a joist. When comparing systems you’ll find that if you can increase the depth of the floor it will allow you to increase your on-center spacing. By doing this you can design the floor with less joists thus reducing the overall cost of the floor system. Thirdly, determine if you have a critical area in the floor that needs special attention such as a marble floor. In this area your deflection criteria would be particularly important. Every floor system is different and often there are multiple factors that need to be considered.

I-joists stresses are lowest near mid-span and highest near the ends. This is evident when you look at hole charts for I-joists, where larger holes are permitted in the web area only, further from the bearings. Notches in I-joist flanges are prohibited and if any are observed the joist should be replaced or be evaluated for a repair.

Some hangers don’t require web stiffeners but this applies when the joist top flange is laterally supported by the sides of the hanger. Although, a designer may need to add web stiffeners when required to increase allowable reaction values. Check with manufacturer’s recommendation when in doubt.

It depends on the applied load even though in most residential construction, the answer is affirmative. However, this applies only when the design load does not exceed the rim board capacity. Check with APA W345.

I-joist or rim board blocking is required under all interior loaded bearing walls or where I-joists are NOT continuous over support.

I would need more specifics where this would apply but to answer the question it is NOT recommended if you’re toe nailing rim board to the end of an I-joist. In other situations it may not cause a problem. Always check with the product manufacturer to verify.

Nailing through the rim board into the end of the I-joist flange is not usually called “toe nailing.” The primary concern of this nailing is mostly on the nail diameter, but it is true that the nail length may increase the likelihood of flange split.

Yes that would be acceptable. Any type of SCL that is the matching depth of the I-joist would be fine.