General information
Fascia caps are placed on the edges of the roof over the CGI sheets and the fascia boards/bargeboards. They serve to securely hold the CGI sheets, ensure waterproofing of the roof, and keep the fascia boards dry to prevent timber from rotting.
The fascia boards are crucial to protect the roof against uplift. Indeed, the fascia boards help to deflect wind and protect the CGI sheets and the roof frame. However, the fascia boards are subject to rainwater and must be protected to prevent them from rotting. Without the fascia boards, laths/battens/purlins and rafters will receive rainwater, may rot and thus make the roof more fragile. To protect the fascia boards, it is necessary to cover them with fascia caps. These caps also contribute to improving uplift resistance by protecting the CGI sheets from lifting, where the wind pressure is twice as strong as that felt on the main part of the roof.
The fascia caps are also made of hot-dip galvanized steel. Their shape is different, but their properties are identical to those of the CGI sheets and ridge cap. They are used for single-pitch, gable and gambrel roofs.
Selection:
The steel grade, steel thickness and protection (zinc coating) used for the fascia cap should be identical to those used for the CGI sheet.
The fascia cap is made of 2 wings. The wing over the CGI sheet should cover 2 corrugations. The wing over the fascia board can be wider to cover the width of the fascia board.
Quality control, safety and storage: identical to CGI sheets
Basic indications regarding the quantity of fascia caps per roof:
Total quantity of fascia caps to order must include the overlapping of each piece with the next one which is 11% of the length to cover:
To have a good approximation of the quantity of fascia caps needed to cover a gable roof (pitch = 20°, wind speed > 150 km/h), you need to:
- measure the length of the roof slope (example: length of roof slope = Lslope = 1.87 m)
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Formula to determine the number of fascia caps needed to cover the roof slope |
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N = Lslope / [length of fascia cap x (1 - % overlapping)] |
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N = Number of facia cap |
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Lslope = length of roof slope |
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length of fascia cap= 1.8 m |
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% overlapping = percentage indicated in table above |
- Example: the percentage of overlapping is 11% à N = 1.87 / [1.80 x (1 – 0.11)] = 1.17 fascia caps
- multiply this value by 4, as there are 4 roof slopes (gable roof) (example: 1.17 x 4 = 4.68 fascia caps)
- round up this value to get the quantity of fascia caps to cover the gable roof (example: 4.68 à 5 fascia caps)
Usage:
Fascia caps are placed on the roof after the CGI sheets but before the ridge caps.
Assemble the fascia caps on wooden frames with roofing nails (see item EHDWNAILRS01). The fascia caps are fastened to every lath/batten/purlin.
Specifications
identical to CGI sheet except the one below:
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Item |
Required value |
Description / note |
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Length (imperial system) |
6ft (1.83 m) |
Most common from 6 – 10ft (1.83 – 3.00 m), as per contract. |
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Length (metric system) |
1.80 m |
Most common from 1.80 – 3.00 m (6 – 10ft), as per contract. |
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Width |
0.25 m (10 inch) |
2 wings of 0.125 m (5 in) minimum |