Roof Components - Ridge Purlin

With the selection list at the top of the dialog box you can choose existing settings. Using the disk icon you can save the current setting under the same name or a new name. Via the management icon you can create new settings, also by adopting existing settings, or modify or delete existing settings. See 'Save settings' in the 'General Help' manual.

Identification number: The identification number determines the purlin material. Using the button at the end of the field, you can branch to the database and select a material.

Designation: The designation simultaneously selects a specific purlin type. Depending on this purlin type, purlins can be positioned differently. For this purpose, some fields in the dialog box change their meaning and labels. For example, the notched purlin is positioned not by a bearing timber but by the notch width and an air gap.

Width: Purlin width.

Height: Purlin height. For the 'notched ridge purlin' the height can be calculated according to the rafters. If you choose the option 'according to rafters', the subsequent fields are activated. There you can enter a rounding value and the cutter height for both sides.

Rounding for height: If the purlin height is calculated according to the rafters, you can enter a rounding value here. The calculated height is then rounded up to the next whole value set here. Thus a value of '0.02m' will always yield heights (cm) of: 10, 12, 14, 16, etc.

Cutter height front side: For the 'according to rafters' calculation, the program requires the cutter heights of the front and rear sides of the ridge purlin.

Cutter height rear side: For the 'according to rafters' calculation, the program requires the cutter heights of the front and rear sides of the ridge purlin.

Position: Level to which the top edge of the bearing timber refers. Typically this is level 0, in which the rafters also lie.

Bearing timber type horizontal / vertical or Notch width front side: This field changes its meaning depending on the selected purlin type. For notched purlins, the notch width for the front roof plane can be entered here. For all other purlin types, the bearing timber type for the front roof plane is set here.

Bearing timber referenced to level or Distance from top edge of level: This field changes its meaning depending on the selected purlin type. For notched purlins, the distance to the top edge of the chosen level of the front roof plane can be entered here. For all other purlin types, the bearing timber corresponding to the bearing timber type is entered here.

Bearing timber type horizontal / vertical or Notch width rear side: This field changes its meaning depending on the selected purlin type. For notched purlins, the notch width for the rear roof plane can be entered here. For all other purlin types, the bearing timber type for the rear roof plane is set here.

Bearing timber referenced to level or Distance from top edge of level rear side: This field changes its meaning depending on the selected purlin type. For notched purlins, the distance to the top edge of the chosen level of the rear roof plane can be entered here. For all other purlin types, the bearing timber corresponding to the bearing timber type is entered here.

Purlin direction: With the 'Purlin direction' option you specify at which end of the purlin the purlin start and at which end the purlin end is located. For this purpose, the roof surface is viewed from the eaves. This information is important when writing the member numbers at the member start on the rafter-purlin plan and when you want to influence the position of the number.

Rafter to purlin connection: There are six settings in this field:

None: No connection is made; both members penetrate each other.

always cut: When penetrating with this purlin, the rafters always receive a cut, even if the rear edge of the purlin penetrates into the rafters.

always cut (consider plates in front of purlin): When penetrating with this purlin, the rafters also always receive a cut, even if the rear edge of the purlin penetrates into the rafters. Additionally, the program searches for plates in front of the purlin. If plates in front of the purlin are found, the cut is increased by the plate thickness. The plates must be perpendicular to the global XoY plane and must be parallel to the front purlin face. The plate must touch the front purlin face and the top edge of the plate can be flush with or at most 20 mm below the top edge of the purlin. The plate can have been created in DICAM or in the wall.

possibly mortise: When penetrating with this purlin, the rafters receive a cut as long as the rear edge of the purlin does not penetrate into the rafters. However, as soon as the rear edge of the purlin penetrates into the rafters, a mortise is created in the rafter. The threshold 'Minimum mortise depth' is taken into account. As long as the mortise depth is less than the value set here, the mortise is not created. A cut continues to appear.

possibly mortise (consider plates in front of purlin): When penetrating with this purlin, the rafters receive a cut as long as the rear edge of the purlin does not penetrate into the rafters. However, as soon as the rear edge of the purlin penetrates into the rafters, a mortise is created in the rafter. The threshold 'Minimum mortise depth' is taken into account. As long as the mortise depth is less than the value set here, the mortise is not created. A cut continues to appear. Additionally, the program searches for plates in front of and behind the purlin. If plates in front of or behind the purlin are found, the cut is increased by the plate thickness. The plates must be perpendicular to the global XoY plane and must be parallel to the front purlin face. The plate must touch the front or rear purlin face and the top edge of the plate can be flush with or at most 20 mm below the top edge of the purlin. The plate can have been created in DICAM or in the wall.

Cut in purlin: With this option no cut or mortise is created in the rafter. Instead, the purlin receives a mortise (free cut).

Rafter nail hole: A rafter nail hole can be created in two ways. It can simply be information attached to the cut or an independent hole can be created. Both options have different characteristics:

From cut: The information for the rafter nail hole is attached as information to the cut, is passed to the machine in that form, and the machine then treats the rafter nail hole as such. This type of rafter nail hole is not displayed in the structure. The diameter of this rafter nail hole is set under 1-7-8 Limits, machining set. This rafter nail hole is created on cuts and free cuts.

Rafter nail hole: Below this group you can choose your own detailed setting. If one of these options is selected, the rafter nail hole is no longer created as information attached to the cut, but a separate hole is created and displayed as such. In addition, the rafter nail can also be created. This rafter nail hole is created on cuts, free cuts (also on hip and valley rafters), on corner cuts and on mortises (for very shallow rafters).

Purlin to purlin connection: With this connection, purlins that meet beneath a hip or valley rafter can be automatically connected to each other. Two connection types are available, each with several options. If both purlins that meet beneath the hip or valley rafter have been assigned different connections, no connection is made.

Section: For the 'Section' connection there are two options. With 'continuous' each of the two purlins is simply cut vertically. At a valley line the purlin is created so that its rear edge ends exactly at the valley line. At a ridge line the purlin is created so that its front edge ends at the ridge line. With the 'angle bisected' option both purlins are cut along the angle bisector.

End plate: With the 'End plate' connection both purlins are connected with an end plate. The end plate can be created according to different criteria. The options of this connection allow you to specify which of the two purlins should receive the end plate on top.

Length at ridge line / valley line: These fields determine the purlin length. Using the ridge line as an example, the following rules apply and the same applies to valley lines:

Up to the ridge line: With this setting the ridge purlin is created as before; it ends at the ridge lines.

Up to rear edge of ridge rafter: The program searches for the wider ridge rafter and extends the purlin so that it ends at the rear edge of that ridge rafter.

Ridge rafter - up to opposite roof plane: The program searches for the roof plane that is intersected by the axis of the purlin. It then extends the purlin up to the top of level 0 of that roof plane and cuts the purlin parallel to that level.

Valley rafter -- up to opposite roof plane: For valley rafters the program also searches for the roof plane that is intersected by the axis. It then extends the purlin to the underside of level 0 of that roof plane and cuts the purlin parallel to that level.

Additionally, there is a field behind each of the two drop-down lists where you can enter a value. A positive value extends the purlin by that value, a negative value shortens the purlin. Thus, for example for a hip roof situation, the purlin can be created up to the top of level 0 of the hip plane with 2 cm clearance.

Shortening at verge: As soon as a purlin ends at the verge as specified, it is shortened by the value entered here. With negative values the purlins are extended.

End machining at verge: As soon as a purlin ends at a verge according to the input, the machining set here is attached to that purlin end. The parameters with which the chosen machining is executed can be viewed and modified using the button at the right end of the field.

Extension of the remaining purlin ends: The purlin ends that are not located at a verge can be extended (positive values) or shortened (negative values) with this setting.

After setting all values and options you can enter the purlins using the following controls:

All ridge lines: The configured ridge purlin is created on all ridge lines.

Continuous: The ridge purlin is created on the roof plane(s) that were selected graphically. If two opposite roof planes that border the same ridge line are selected, the ridge purlin is created only once.

Length-limited: By two points the length and position of the purlins can be defined. The first entered point simultaneously determines the roof plane on which the purlin shall be created.