Every ClearCalcs project has a button in the sidebar called Project Defaults. These are a set of default/preset values for the country code in question.
They are carried through to every new calculation that is created. The purpose of this guide is to clarify the use of these defaults, and which calculators are impacted by each option.
You can still override any of these defaults in a specific calculator by selecting the field in question and manually typing over it. These defaults are purely to save you time, and you don't need to use them if you don't want to. If you copy a project, any project defaults will be copied along with the calculations.
The main sections in Project Defaults are:
1. Building Site 2. Building geometry (e.g. beam spacings, storey heights, roof slope) 3. Design criteria / Load Combinations (e.g. default deflection limits, design code) 4. Default Loads (e.g. default roof, floor, wall & window loads) 5. Load Cases (e.g. standards based, custom)
The wind class obtains the relevant gust pressures from AS 4055:2012 Cl 3.3 and gust wind speeds from Table 2.1(A-B). These values are then used in the Wind Load section of various calculators.
In the design of timber structures, this factor is used as a default temperature factor.
Where 2 or more stories, additional options will be provided for "Lower Floor" heights as well as "Top Floor". Note this is typically used with the "CalcsCAD" tool only.
The slope of the roof is set on all calculators for design of roof beams, and for the beam and wind analysis calculators. This angle CAN be changed in individual rafter calculators if roof slopes differ through out the project.
Spacings are used to calculate default distributed loads in rafters and joists. Refer to article What is tributary width? for details about how distributed loads are calculated.
Quick Tip: Did you know that rafters or joists may be linked into other beams (e.g. floor bearer) as a line load? This means you only have to create a single rafter / joist and then ClearCalcs will use the spacing to regularly space the reactions. Refer to this article for details. Of course the values may be overridden within each calculator. See example from the "Steel Beam" calculator:
Default heights for most columns (depends on if column is part of a typical light framing or heavy framing system).
Tributary width for distributed wall loads.
Does your structure have space constraints? ClearCalcs will check the depth of your beam, and compare it with the Maximum Roof Beam Depth set below.
Deflection limits may be set that will be defaulted in all calculators where applicable.
Deflection limits must be changed within the individual templates. A hard limit is provided in the Project Defaults which overrides any span limits, which may be also be set.
A bearing check is completed for beams. This length is along the length of the beam (i.e. length of supporting member/column).
Roof
Roof Default Load Table is dynamically set based on the selection of criteria for "Roof Permanent" and "Roof Imposed" Load selections. The following calculation types import these default loads (Timber / Steel / CFS Beams).
The character of Imposed Load is used to set the load factors based on the expected duration (e.g. short-term, medium-term, long-term) of the applied loads.
Ceiling
Where the ceiling applies a dead load to hanging beams, this permanent load is applied by default to the calculator.
Floors have default area loads depending on the structures' intended use. The "Live Load Selection" is used to set the "Default Floor Loads" details in the dropdown menu.
The character of Imposed Load is used to set the load factors based on the expected duration (e.g. short-term, medium-term, long-term) of the applied loads.
Wall
Wall loads are automatically defaulted based on the various selectors at the top of the section.
When used in a calculator, the wall weight below is multiplied by height of wall above the structure (e.g full height wall for floor headers) and entered as a Distributed Load.
The wall framing loads are selected from AS 1720.3:2016, Table 3.3.2.2(A). The coverings on internal wall loads are selected from AS/NZS 1170.1:2002, Table A2
The wall weights are determined by taking the weight of covering each face as well as the weight of the wall
Window
The window area load can be manually set below.
When used in the Wall Analysis with Load Combinations calculator, the window weight is added to the Self-weight of the structure and may be overridden in the "SW_Window" input.
This is used within the Wall Analysis (Railing) calculator. It is used to set the height of the wall that affects its self-weight.
This calculator provides a choice of standards/clauses to use to determine load combinations. You may also select "Custom load combinations" at the bottom of the drop downs and enter custom combinations.
A range of AS 1170 load combinations standards are provided for Strength and Serviceability. These affect the load combinations in all design calculators (e.g. Timber & Steel Beam/Column). Why would you want to set custom combinations?
Quick Tip: Did you know that you can create a template project with custom load combinations and duplicate from there instead of create new project defaults each time.
Each calculation has "alternative" live load combinations, which are not intended to be applied at the same time (e.g. during construction imposed load vs post-construction residential loads). These are represented by Q, Q2 and Q3. When linking loads, you can choose to only transfer through the main load (i.e. the alternative construction load does not need to be applied to others part of the structure).
Generally this load shouldn’t actually be linked through the load path in the building - it should just be an alternate load for individual members only.
Select “Yes” here to exclude these loads from all load linking throughout this project.
When selecting Custom combinations, a table of combinations is given. For timber calculations, an additional "Duration" column is used that modifies the strength properties of the timber.
Congratulations! You've reached the end of this guide.