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Span Type
An input has been added to specify how the program interprets the span values entered:
Design Span
This is the distance between support points on beams. Support points for exterior supports are ½ the minimum required bearing length from the inside of the support. For interior supports, they are at the centre of the support.
Clear span
This is the distance between the inside faces of the supports, for all spans.
Full span
This span is measured from the outside faces of exterior supports, to the centre of interior supports. It is the beam length for single-span members.
Support Type
For each support, you can specify the following:
Hanger
The hanger indicates a steel hanger is used for the beam. . If this is chosen, supporting member design is not part of the bearing design routine, and the Material, Species and Grade inputs are unknown. It does, however, have a list of bearing sizes representing common hanger lengths.
Other non-wood
This is chosen to indicate that the supporting member is made of concrete, steel or some other material not designed by WoodWorks. If this is chosen, supporting member design is not part of the bearing design routine, and the Material, Species and Grade inputs are disabled and blanked out. This option also does not have a list of bearing lengths associated with it, and it designs for minimum or rounded minimum instead.
This option is available for supported beams and joists.
Sill Plate
This choice is for a 2-inch thick wooden member which is assumed to lie on the flat, usually affixed to a concrete or block foundation. The program implements a special set of sill plate database materials, using essentially joist database files. The bearing length information is taken from the “d” dimension of the sill plate materials.
This option is available for supported beams and joists.
Beam
The supported member is assumed to be a beam, so that the material, species, grade, and bearing length information comes from our beam database files. The bearing length info is taken from the “b” dimension of the beam.
This option is available for supported beams and joists.
Column
The supported member is assumed to be a column, so that the material, species, grade, and bearing length information comes from our column database files. The bearing design choices are taken from all of those from the “b” or “d” dimension of the column could be oriented either way. .
This option is available only for supported beams.
Wall
The supported member is assumed to be a wall, so that the material, species, grade, and bearing length information come from our wall database files. The bearing length information is taken from the “d” dimension of the wall plate.
This option is available only for supported joists.
Material, Species, and Grade
You can input these parameters for each supported member, similar as the inputs for Material, Species, and Grade for the main member. The information comes from the WoodWorks materials database.
Bearing Length
This field represents the length parallel to the supported member that is supported. The program allows for
Bearing at Support End
The checkbox “Bearing at Support End” indicates that the supporting member ends at the supported member, so that the bearing length factor CB is not applied.
For unknown bearing length…
This field allows for a choice of bearing design option for all supports in which Unknown is selected as the Bearing length choice. The choice affects the actual bearing length that the program determines is supporting the beam.
Use exact minimum
In this case, the program designs for minimum required bearing length and use that exact length as the bearing length for each support. This is how the program currently works.
Round minimum up to nearest
With this choice, the program determines the minimum required bearing length, and rounds it to the nearest increment as indicated by you.
This option corresponds to the case where the beam sits only partially on an end support, but you want to have a bearing length and a total beam length that are reasonably round numbers for measuring and cutting.
From Bearing Length list
In this case, the program rounds up to the next choice in the dropdown box that was derived from the section sizes of the supporting members or from the standard hanger sizes.. Refer to vi Bearing Length, above, for the choices of section sizes for each member type and orientation.
End Supports: Round minimum; Interior: From bearing lengths
This option allows you to model a situation where a beam sits only partially on end supports but fully on interior supports. Enabled only when there are interior supports in the member, including cantilever supports. Its behaviour is a self-explanatory combination of the previous two options.
Bearing Length and Design Spans
This feature related to the span input in that the choice of the bearing length method used has an impact on either the actual length of the beam, the clear span, and/or the design, depending on whether you choose to enter clear span, design span, or fixed beam length.
Clear span or design span
If you enter clear span, then the bearing design choice does not affect the length of design span, as the design span is clear span + minimum bearing. Similarly, if the design span is entered (as it is currently in Sizer), the clear span is not affected. For these cases, only the beam length changes based on the choice of bearing length design method.
Actual beam length
If the beam length is what is assumed to be entered, then the choice of bearing length method affects the length of design span and the length of clear span. As a result, this choice has an impact on the shear, moment, reactions, etc. Indirectly, due to change in clear span, it has an effect on notch design and, shear at distance d,. as well.
Minimum Bearing Length Options in Design Settings
A group in the Design Settings called Minimum Bearing Length has been added with two inputs
End supports
Interior supports
Beside the End supports item, there is a checkbox that says
Use to determine design span.
End Supports/Interior supports
The values entered in these boxes indicate the smallest bearing the program is able to design for, for interior and end supports separately. If the program calculates a minimum bearing less than this value, it overrides it with the value entered.
Use to determine design span
You may wish that the program would never design a bearing less than some practical amount, say 3.5”, however you may wish to take advantage of the reduced design span from using only the minimum required bearing length. For this reason, we allow you to opt out of using the minimum bearing you entered in your calculation of design spans. The program in this case uses the minimum required bearing for design span, but you enter span for bearing design.