Panel widths

Note

This chapter is not applicable due to different national regulations for Germany and Switzerland. For further information, please contact the Product Technology department of the respective country!

For standing seam applications observe local wind load conditions to determine panel width and spacing of clips. PREFA has prepared simplified dimensioning tables for professional installers. The simplified dimensions only apply to closed structures and only for PREFALZ or FALZONAL in combination with PREFA fixed and sliding clips and associated fasteners (nails/screws) from PREFA and when installing on full formwork with a bituminous separation layer. The tables are created based on EN 1991-1-4. Please refer to EN 1991-1-4 for the terrain category and to national supplements to EN 1991-1-4 for the base speed. The roof areas have been optimised to two areas and renamed (R = edge area, N = main area). The wind loads are higher at the edges of buildings and require special attention.

Building height: Greatest height of the building (e.g. ridge, hip)

The panel width is calculated from coil width minus seam loss:

For handcrafted panels: ~80 mm (e.g. 650 g ~570 mm / 500 g ~420 mm)
When using a profiling machine: ~70 mm (e.g. 650 g ~ 580 mm / 500 g ~ 430 mm).

Specification of the maximum recommended fold spacing [cm] depending on the terrain category, building height and basic wind speed. The values given in the table are empirical values. The specified panel widths do not take into account waste when using standard coil dimensions.

Basic speed pressure [kN/m²]	Basic speed [m/sec]	Building height < 15 [m]	Building height 15-30 [m]	Building height 30-50 [m]
		N \| R [cm]	N \| R [cm]	N \| R [cm]
≤ 0.32	≤ 22.5	58 \| 50	58 \| 47	43 \| 43
≤ 0.39	≤ 25.0	58 \| 47	43 \| 43	43 \| 43
≤ 0.47	≤ 27.5	43 \| 43	43 \| 42	43 \| 26
≤ 0.56	≤ 30.0	43 \| 42	43 \| 35	43 \| 26

Basic speed pressure [kN/m²]	Basic speed [m/sec]	Building height < 15 [m]	Building height 15-30 [m]	Building height 30-50 [m]
		N \| R [cm]	N \| R [cm]	N \| R [cm]
≤ 0.32	≤ 22.5	58 \| 52	58 \| 49	58 \| 47
≤ 0.39	≤ 25.0	58 \| 49	58 \| 46	43 \| 43
≤ 0.47	≤ 27.5	58 \| 47	43 \| 43	43 \| 42
≤ 0.56	≤ 30.0	43 \| 43	43 \| 41	43 \| 34

Basic speed pressure [kN/m²]	Basic speed [m/sec]	Building height < 15 [m]	Building height 15-30 [m]	Building height 30-50 [m]
		N \| R [cm]	N \| R [cm]	N \| R [cm]
≤ 0.32	≤ 22.5	58 \| 58	58 \| 53	58 \| 50
≤ 0.39	≤ 25.0	58 \| 54	58 \| 50	58 \| 48
≤ 0.47	≤ 27.5	58 \| 51	58 \| 48	43 \| 43
≤ 0.56	≤ 30.0	58 \| 49	43 \| 43	43 \| 43

Note

For assistance with calculations for projects in exposed locations, please contact the PREFA Product Technology Department at office.uk@prefa.com.

Terrain category 0 - lakes and coastal areas exposed to the open sea.

Terrain category I - lakes and areas with low vegetation and without obstacles.

Terrain category II - areas with low vegetation such as grass and individual obstacles (trees, buildings) with a distance of at least 20 times obstacle height.

Terrain category III - areas with uniform vegetation and buildings or with individual objects with distances of less than 20 times obstacle height (e.g. villages, suburban developments, forest areas).

Terrain category IV - areas where at least 15% of the surface is covered with buildings with an average height of 15 metres.

Terrain categories according to EN 1991-1-4

Basic speed pressure [kN/m²]	Basic speed [m/sec]	Building height < 15 [m]	Building height 15-30 [m]	Building height 30-50 [m]
		N \| R [cm]	N \| R [cm]	N \| R [cm]
≤ 0.32	≤ 22.5	58 \| 50	58 \| 47	43 \| 43
≤ 0.39	≤ 25.0	58 \| 47	43 \| 43	43 \| 43
≤ 0.47	≤ 27.5	43 \| 43	43 \| 42	43 \| 26
≤ 0.56	≤ 30.0	43 \| 42	43 \| 35	43 \| 26

Basic speed pressure [kN/m²]	Basic speed [m/sec]	Building height < 15 [m]	Building height 15-30 [m]	Building height 30-50 [m]
		N \| R [cm]	N \| R [cm]	N \| R [cm]
≤ 0.32	≤ 22.5	58 \| 52	58 \| 49	58 \| 47
≤ 0.39	≤ 25.0	58 \| 49	58 \| 46	43 \| 43
≤ 0.47	≤ 27.5	58 \| 47	43 \| 43	43 \| 42
≤ 0.56	≤ 30.0	43 \| 43	43 \| 41	43 \| 34

Basic speed pressure [kN/m²]	Basic speed [m/sec]	Building height < 15 [m]	Building height 15-30 [m]	Building height 30-50 [m]
		N \| R [cm]	N \| R [cm]	N \| R [cm]
≤ 0.32	≤ 22.5	58 \| 58	58 \| 53	58 \| 50
≤ 0.39	≤ 25.0	58 \| 54	58 \| 50	58 \| 48
≤ 0.47	≤ 27.5	58 \| 51	58 \| 48	43 \| 43
≤ 0.56	≤ 30.0	58 \| 49	43 \| 43	43 \| 43

Panel widths

Simplified calculation of maximum panel width [cm]

Note