Everything new in Version 4.3 summed up in one convenient place

National Masonry Design Programs, NMDP, is proud to announce the official release of MASS Version 4.3.2, which rectifies critical software bugs before the release of MASS Version 5.0 which will update MASS to CSA S304-24 and NBCC 2025.

This new version is available to all current license holders at no extra charge and can be downloaded for free using the link below:

Click here to visit the Downloads page

We have provided a detailed breakdown of the most significant changes below, along with explanations for each. If there are questions regarding any of these changes or the reasoning behind them, please feel free to contact technical support!

Jump ahead by expanding the contents section here.

Technical Changes

ꞵd Calculation

Previously in MASS, if there was no dead, line load acting along the face of an out-of-plane wall, the ꞵd value was taken as zero.

In Version 4.3.2, this calculation has been updated to account for cases where no dead, line load is present, but a dead, axial load is applied. In these cases, MASS now uses the minimum primary moment calculation to determine the dead load moment from the applied dead, axial load. This provides a more representative βd value where dead, axial load contributes to the wall’s out-of-plane bending demand.

Shear Resistance Location

In previous versions of MASS, diagonal shear resistance was calculated at each course along the height of the wall.

In Version 4.3.2, this calculation has been updated to better align with the design approach presented in our textbook and in our course. Diagonal shear resistance is now calculated only at the base of the floor, rather than at every course. This provides consistency across CMDC initiatives.

Comprehensive Analysis for Conventional Construction Walls

In previous versions of MASS, the option to perform a comprehensive analysis was always available. In some cases, this allowed users to select the option for walls where the comprehensive analysis method was not applicable, resulting in design outputs that did not reflect the intended analysis approach.

In Version 4.3.2, this option is now only available in scenarios where comprehensive analysis can be used. This helps ensure that conventional construction walls are analyzed using the appropriate design method.

Click here for more information about the Comprehensive Analysis of Conventional Construction Walls.

Behave Elastically Detailed Calculations

In Version 4.3, MASS incorporated the NBCC 2020 Clause 4.1.8.23 requirements for shear walls required to behave elastically in certain cases. While this check was included in the design, the full supporting calculations were not shown in the results.

In Version 4.3.2, MASS now displays the complete calculations whenever the elastic behaviour check is required. These calculations are shown in both the Simplified Results and Detailed Results tabs, making it easier to review how the check has been evaluated.

Bug Fixes

Incorrect Load Combinations

In previous versions of MASS, when a Live (Storage) load was selected as a load acting on the element, some load combinations were generated incorrectly. In these cases, MASS incorrectly applied both companion loads alongside the principal load, rather than applying only one companion load at a time.

This has been corrected in Version 4.3.2. MASS now generates the applicable load combinations using the correct companion load treatment for Live (Storage) loading.

Shearline Pier Deflection Results

In previous versions of MASS, the Deflection tab under the Simplified Results for piers generated from the Shearline module did not always display the correct deflection information. In some cases, the Simplified Results tab did not initially show any deflection values for a pier, even though the Detailed Results included the calculated values.

In addition, when the Moment and Deflection Design was run while viewing this tab, the Simplified Results table could populate with deflection values that did not match the Detailed Results. This issue was limited to pier tabs created through the Shearline module and did not occur in the Shear Wall module or in pier tabs created through the Multi-Storey Shear Wall module.

This has been corrected in Version 4.3.2. The Simplified Results, Detailed Results, and deflection diagram now report consistent deflection values for piers generated through the Shearline module, including fixed-fixed piers.

Cell-by-Cell Design for Shear Walls

In previous versions of MASS, some users experienced issues when using Cell-by-Cell Design to place vertical reinforcement in shear walls. This occurred when a moment analysis had been run and the reinforcement layout was adjusted afterward, causing MASS to close unexpectedly.

This has been corrected in Version 4.3.2. Users can now adjust vertical reinforcement using Cell-by-Cell Design after running a moment analysis without the program closing unexpectedly.

Shear Wall Detailed Results Outputs

In previous versions of MASS, the Detailed Shear Results for shear walls displayed certain moment resistance and neutral axis depth values regardless of the ductility category selected. Specifically, Mr,nom and cnom, which are only required for moderately ductile shear walls, and Mr,prob and cprob, which are only required for ductile shear walls, could be shown even when they were not applicable to the selected shear wall ductility.

This has been corrected in Version 4.3.2. MASS now only displays these values when they are applicable to the selected ductility category. This helps simplify the Detailed Shear Results and ensures that only the relevant design information is shown.

Vertical Steel Spacing Selection

In Version 4.3, vertical reinforcement spacing options were automatically reselected when running a design, even after they had been deselected by the user.

This issue has been resolved in Version 4.3.2. MASS now preserves the user’s selected vertical reinforcement spacing options when the design is run.

Out-of-Plane Wall Shear Results for Unreinforced Walls

In previous versions of MASS, when an unreinforced out-of-plane wall was designed and the shear analysis was run, the shear table in the Simplified Results tab was not generated. This issue only occurred for unreinforced sections. For reinforced out-of-plane walls, the Simplified Results table was generated as expected.

Although the shear drawing was still generated, indicating that the shear values were being calculated, the corresponding Simplified Results table was not displayed.

This has been corrected in Version 4.3.2. MASS now generates the Simplified Results shear table for unreinforced out-of-plane walls when a shear analysis is run.

Top Reinforcement for Beam Shear Design

In Version 4.3, beam designs could fail in cases where no top reinforcement was required for moment resistance, but stirrups were required for shear resistance. Since no top bar was provided, the stirrups did not have reinforcement to anchor to, resulting in a failed design.

This has been corrected in Version 4.3.2. When stirrups are required for shear design, MASS now provides a top bar in the beam to allow the stirrups to be properly anchored.

Beam Stress Distribution Selection

In previous versions of MASS, the default stress distribution in the Beam module was changed from triangular to rectangular. In addition, when a triangular stress distribution was selected and the file was saved, reopening the file would show the stress distribution as rectangular, even though the calculations were still being completed correctly using the triangular distribution.

This has been corrected in Version 4.3.2. The Beam module now uses triangular stress distribution as the default, and saved files now correctly display the selected stress distribution when reopened.