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Regular rectangular roofing (Rechteck-deckung)
Double rectangular roofing
The main characteristic of the double rectangular roofing is that the third row still overlaps the first one and the tiles are laid bonded. With this tiling method it is a rule that the lower the inclination of the roof and the longer the rafters, the shorter the slates used and the bigger the head lap.
Underlayment
Battening (min. 40x60 or 50x50 cm), full-surface sheeting, nailing building panels, nailing masonry.
Minimal head lap
The minimal head lap must take the following values:
| Shape | 40/40 | 35/35 | ||||
| 60/30 | 40/25 | 35/25 | 30/30 | |||
| Roof pitch | 50/25 | 40/20 | 35/20 | 30/20 | ||
| General roof angles | Vertical overlap in mm | |||||
| > 22° | 120 | - | - | - | ||
| > 30° | 100 | 100 | - | - | ||
| > 40° | 80 | 80 | 80 | - | ||
| > 50° | - | 60 | 60 | 60 | ||
| Width Height cm | Pcs/m2 In case of double-roofing
With an overlap of 8 cm |
kg/ 1000 Pcs | Pcs/pallet appr. |
| 60/30 | 12,8 | 2410 | 560 |
| 50/25 | 19,0 | 1720 | 650 |
| 40/25 | 25,0 | 1380 | 1050 |
| 35/25 | 29,6 | 1210 | 1150 |
| 40/20 | 31,3 | 1100 | 1250 |
| 35/20 | 37,0 | 970 | 1450 |
| 30/20 | 41,7* | 750 | 1700 |
Multiple head lap, depending on the length of the rafters. In case of a lower incline, the head lap has to be increased by 2% after each degree it diverges. Regarding tiling on roof lathing the head lap must not be smaller than 60 mm. As for a pitch below 35o at least 230 mm wide slates have to be used.
Considering wall tiling, in case of nailing the minimal vertical lap is 2 cm, in case of clipping it is 6 cm, depending on the position of the clips (70' clips).
Th shape of the slates
Rake, hip, ridge, eave
The starter row is tiled with the starter elements which are laid by size and fastened by slips or nails. The starter elements are completely covered by the full-size slates of the first visible eave row. The rakes are tiled as covering rows with at least one slate, with an overhang or without it (a drainage groove must be cut). Ridges have to be slated with single vertical overlaps. Hips are tiled as bonded and overlaid edges where you have to pay attention to the proper overlap.
The well-known forms of double roofing
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