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Status Planned
Created by Guest
Created on Sep 21, 2026

Correct Roof Live Load vs Snow Load Combinations for joist design

From the RAM Manager, the Criteria > Member Loads dialog has a section labeled "Snow vs Roof Live Load" and says "From version 2026, both roof and snow loads are considered." In ASCE 7-16 and 7-22 section 2.2 "Symbols", and IBC 2021 section 1602.1 "Notations", there is a clearly defined parameter "Lr" that is called "Roof live load".

In ASCE 7-16 and ASCE 7-22, the live roof load, Lr, is never taken in combination with the snow load. It is always listed (Lr or S or R). IBC 2021 refer to ASCE 7 for it's load combinations and therefore matches nomenclature.

Based on this understanding of the code definitions of these terms, the intuitive interpretation is that RAM is "considering" "Roof live load" and "Snow load" in separate combinations and using the worst case to design the members.

However, RAM is clearly considering snow loads and live loads labeled as "Roof" loads in the "Surface Load Properties" at the same time for joists. I verified this by looking at the applied load and design report, which clearly combined the "live load" of type "roof" with the snow load. This is very contrary to the expect behavior, and produces loads significantly higher than considering either "roof live load" or "snow load". It's also inconsistent with beams that are being designed for LRFD, which is properly separating roof live load and snow load.

This confusing presentation can lead to costly oversights and I strongly encourage at minimum that the language be revised. Ideally, RAM would offer additional functionality that allows both "roof live loads" as defined by code and "snow loads" be considered in their own separate load combinations for joists. Members would then be designed for the worst cast of these designs. This would be a helpful and efficient coverage of possibilities for users and a very welcomed feature I know at least our firm has been dreaming of for a long time.

See the attached for examples of the dialogs and reports mentioned in this product support request.

My RAM Manager Version: 26.00.00.222.

  • Admin
    Seth Guthrie
    Sep 29, 2026

    This is already planned for changes either in v 26.00.01 or in version 27. Current behavior in 26.00.00 includes both types of loads as noted above and in the 26.00 release notes. We are in communication with SJI regarding the proper combinations to use, presumably the ASCE 7-22 ASD form load combinations.