Stratco offers the services of curved or bullnosed CGI profile sheets which are ideally suited to verandah applications. Whether you are renovating a Federation-style villa, or building a modern home, Stratco can provide the finishing touch with convex or concave profiled sheets. The curve can be rolled with a radius to specifically suit your requirements.
Note: Curving of CGI will produce a minimum straight section at the end of the curve of at least 60mm. Stratco takes no responsibility for deformation that may occur from smaller radii. Please contact Stratco for further curving specifications.
Supply of profile template. Template must be provided at time of ordering. No responsibility will be accepted for sheets curved from drawings.
a - Distance from fascia front to wall. b - Distance from fascia height to wall attachment. c - Required dip for concave or rise for convex. d - Pitch angle from wall. r - Radius required.
• Number of sheets required. • Direction of laying. • Sheet lengths required. • Type of material. • Type of curve. • If colour, is it required to • If 50 mm gutter overhang is required topside or underside?
Bullnose Forming
Recommended minimum radius 450mm. Maximum sheet length 6000mm.
Concave/Convex Forming
Recommended minimum radius 450mm. Maximum sheet length 6000mm.
Barrel Vaulting
Recommended minimum radius 450mm. Maximum sheet length 10,000mm.
Finish your curving project with accessories manufactured by Stratco such as curved flashings to match your sheeting radius and curved hip bars for bracing the hip joint.
Stratco can curve your CGI curving sheet into a variety of forms to produce bullnose roofing or barrel vaulting (a complete half circle), in either concave or convex arrangements. Finish your curving project with accessories manufactured by Stratco such as curved flashings to match your sheeting radius and curved hip bars for bracing the hip joint.
Maximum recommended curving radius is 450mm. Sheet coverage is 762mm.
Sheet Length and Curving Calculation Procedure
Bullnose Verandahs
Step 1 Dimensions Required: Width of Verandah - wall to outside face of fascia beam (X) Height - top of fascia beam to underside of verandah sheet (Y) Plot these lines to scale on graph paper.
Step 2 Draw the straight section of sheet (A) at the required fall. Note: Corrugated iron is not recommended for a pitch of less than 5 degrees.
Step 3 Determine the radius of curvature. Note: The recommended minimum radius for CGI curving is 450mm. Stratco takes no responsibility for deformation that may occur from smaller radii.
Step 4 Set a compass to the radius of curvature and scribe arcs from both ends of line (A). Connect arc tangents to form parallel line (B). Set the compass point to the top front corner of the fascia Beam (C) and scribe an arc to intersect line B. From this intersection (D) set the compass point and scribe an arc from line (A) to a point 50mm past the fascia (E).
Step 5 Calculating the roof sheet length:
• Extend a perpendicular line from point (D) to intersect line (A) • Draw a line from point (D) to point (E) • Measure the resulting angle (F°) • Measure the length of straight sheet • Calculate the length of curvature using the following formula:
2πr x angle (F°) 360
• Add the length of straight sheet to the curve length to determinethe total sheet length
Concave & Convex Verandahs
Step 1 Dimensions Required: Width of Verandah - wall to outside face of fascia beam (X) Height - top of fascia beam to underside of verandah sheet (Y) Plot these lines to scale on graph paper.
Step2 Draw a straight line (A) between the wall and fascia beam as shown in Figure 3 (overleaf). Locate the mid-point of line (A) and plot a perpendicular line (B) from this point. Determine the required dip and plot the point of intersection (C) on line (B).
Step 3 Using a flexible scale ruler, join the top and bottom of line (A) through point (C). Read the required sheet length from the scale ruler, allowing an additional 50mm past the fascia. If required, adjust the dip to effectively suit the fall into gutter. Note: A minimum dip of 50mm is recommended for aesthetic reasons.
For convex verandahs repeat Step 1 to 3, however, plot intersection point (C) on the opposite side of line (A) at the required convex rise, refer to Figure 4.
