Roof Components - Valley Rafters

The valley rafter input

With the selection list at the top of the dialog box you can choose existing settings. Using the floppy-disk icon you can save the current setting under the same name or a new name. Via the management icon new settings can be created, also by adopting existing settings, existing settings can be modified or deleted. See 'Save settings' in the 'General Help' manual for details.

Identification number: The identification number determines the material of the valley rafter. Using the button at the end of the field you can branch into the database and select a material.

Width: Width of the valley rafter.

Height: Height of the valley rafter. For the height a fixed value can be entered or it can be calculated from the rafters. If you choose the option 'by rafters', the following fields are activated. There you can enter a rounding value and the shift height for both sides.

If double valley rafters are used, the height of the 1st (upper) valley rafter can also be calculated dependent on the 2nd (lower) valley rafter. How the 2nd valley rafter is positioned can be seen in the helper images on the 'Chamfer edges' field. Depending on this position, the height of the 1st valley rafter results.

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

Shift height left: For the calculation 'by rafters' the program requires the shift heights from the left and the right side of the valley rafter.

Shift height right: For the calculation 'by rafters' the program requires the shift heights from the left and the right side of the valley rafter.

Base offset: There are different options for the base offset:

None: Even with unequal roof pitches the valley rafter is not offset; it is installed centered to the ridge line. The side surfaces are then of different heights.

Chamfer heights equal: The valley rafter is offset so that the chamfer heights of the valley rafter and thus the height of the side surfaces are equal. If the valley rafter height is calculated from the rafters, this base offset then causes one of the two shifts to end exactly at the underside of the valley rafter and the other shift somewhat higher (the valley rafter projects beyond the underside of the shift).

Shift flush: The valley rafter is offset so that both shifts are flush with the underside of the valley rafter. The chamfer heights are then, however, different.

Value: The base offset can be freely controlled by entering a value.

Layer: Layer in which the valley rafter is to be installed. Typically this is layer 0, in which the rafters also lie.

Lower by: With this value the valley rafter can be lowered by the entered amount.

Width of the non-chamfered area: Here a width can be entered over which the valley rafter will not be chamfered. The valley rafter is not lowered for this; rather it retains its position. It becomes lower by the corresponding amount.

Formation of the valley rafter underside: The valley rafter can be straight or scooped on the underside. The scoop depth and the angles are generated automatically. If you have the valley rafter height calculated from the rafters, set the rounding to 0.0 and the base offset to 'Shift flush', you will obtain a smooth transition between shift and scoop.

Ignore openings, valley rafter passes through opening: If this option is set to 'Yes', then the valley rafter ignores an opening that lies exactly on the ridge line. The valley rafter is then not split. This is useful when the valley rafter should first be installed completely and only be separated on the construction site.

The connections of the valley rafters

Rafter nail drilling: A rafter nail drilling can be generated in two ways. It can simply be information at the kerf or it can create a dedicated drill hole. Normally the rafter nail drilling is set on the purlin and all rafters, inclined rafters, valley rafters and hip rafters that receive a kerf from that purlin also receive that rafter nail drilling. In some cases, however, a single component should receive a different rafter nail drilling. Then you can give that component its own setting for this. Both options have different properties:

From purlin: The rafter nail drilling is adopted from the purlin that creates the kerf in the valley rafter. This can be a rafter nail drilling as information at the kerf or a separate rafter nail drilling, depending on the purlin setting.

Rafter nail drilling: Below this group you can choose your own detailed setting that then applies only to this valley rafter and "overrides" the purlin setting. If one of these options is chosen the rafter nail drilling is no longer generated as information at the kerf, but a standalone drilling is created that is represented as such. Additionally the rafter nail can also be generated.

Valley rafter at left eaves: For the connection of the valley rafters to an eaves you can optionally set the option 'section' or '2 sections'. Which parameters are used to execute the chosen processing can be viewed and changed using the button at the right end of the field.

Valley rafter at right eaves: Different settings can be made for the right and left side of the valley rafter (as seen from the eaves). Depending on the chosen settings, conflict situations may arise that lead to different sections than expected. In such a case you should check the setting for the left and the right side.

Valley rafter at ridge: As soon as a valley rafter ends at a ridge line, it receives the connection set here. With the option '1 plumb cut' it is cut parallel to the ridge, with the option '2 plumb cuts' it is cut parallel to the ridge on one side and perpendicular to the ridge on the other side. As soon as multiple valley rafters converge at a point, they automatically intersect with each other in the contact area. The valley rafters automatically receive an air gap at the ridge if this is configured under 'File - Settings - Limits, Operations'.

Valley rafter at roof kink: When a valley rafter ends at a roof kink, it receives one of the connections possible here. With the option '2 plumb cuts' the valley rafter is cut plumb at both kink lines. With the option 'Adapt' the valley rafter is adapted to the already existing other valley rafter. Therefore it depends on how that connecting valley rafter is shaped.

Double valley rafter: A second valley rafter can be created beneath the normal valley rafter. Both valley rafters are positioned dependent on each other. With the option 'centered' a second valley rafter is generated. It is automatically placed centered beneath the upper valley rafter.

Width: Width of the 2nd valley rafter.

Height: Height of the 2nd valley rafter.

Setback from the building contour: Usually the 2nd valley rafter does not end at the eaves like the upper one, but ends at the building contour or at a defined distance to it. This distance, referenced to the building contour, can be entered here.

Chamfer edges: This option is only available if in the 'Height' field for the first valley rafter the option 'by 2nd valley r.' was set. There are the following possibilities:

None: No edge of the valley rafter is chamfered. The valley rafter is pushed upwards until the first edge abuts the bottom edge of the rafters (depending on the rafter height entered above).

One-sided: At most one edge is chamfered. That means: with two equally pitched roof surfaces no edge is chamfered. The 2nd valley rafter is pushed upward until both edges of the valley rafter abut the roof surfaces. With unequally pitched roof surfaces the valley rafter is pushed upward until the valley rafter edge on the shallower side abuts the bottom edge of the rafters. The valley rafter edge on the steeper roof side is then chamfered accordingly.

Two-sided: At most two edges of the valley rafter are chamfered. With two equally pitched roof surfaces both edges are chamfered. With unequally pitched roof surfaces the valley rafter is pushed upward until the valley rafter edge on the shallower side abuts the bottom edge of the rafters. The valley rafter edge on the steeper roof side is then chamfered accordingly.

After setting all values and options you can input the valley rafters using the following buttons:

All ridge lines: The configured valley rafter is generated on all ridge lines.

Ridge lines: The valley rafter is generated on the ridge line or lines that were selected graphically.

Length-limited: The length and position of the valley rafter can be entered via two points.