Quick conclusion
Want to install roofing sheetsComposite alternating non-leaking metal sheets, first both panels must match the profile and be fixed according to the guidance of the correct roofing system. Overlaps, types of screws–washers, expansion holes, tightening force, and sealing materials must be approved in a coordinated manner; sealant cannot compensate for incorrect shapes.
Staggered installation is a system, not just replacing a single panel
FRP sheets, metal roofing, purlins, screws, washers, sealing tape, and overlapping details must be compatible. Official manufacturer guidance for the roofing system takes higher priority than general installation tips, especially regarding screw positions, hole sizes, overlaps, and tightening sequence.
Side overlapping and end overlapping
- Right edge aligns with profile; do not stretch to fit another sheet wave.
- Overlap the panels, then consider the drainage direction and the prevailing wind direction.
- End lap is only used when the roof system allows; lap length, position on the purlin, and sealing tape must follow the approved documents.
- Do not create back slope points or water pockets at the joints.
Screws, washers, and expansion holes
| Control point | Requirement |
|---|---|
| Screw type | Suitable for purlin material and corrosive environment |
| Washer | Force distribution, sealing, and compatibility with sheets |
| Drill hole | Follow instructions to allow thermal displacement; do not drill too close to the edge. |
| Tightening force | Sealed enough but not pressed in, cracked, or whitened the panel |
| Seam connecting screw | Correct position and distance of the roof system |
Leak-proofing starts from geometry and drainage
Sealant does not fix incorrect profiles, inverted slopes, or torn screw holes. Before adding sealant, check water flow, bearing flatness, overlapping edges, sheet deformation, washers, and thermal displacement. Only use tape/adhesive confirmed to be compatible with FRP and outdoor conditions.
Checklist for acceptance before rain test
- Correct profile, installation direction, overlapping edge, and length.
- No cracks, stress whitening, misaligned holes, or over-tightened screws.
- Sufficient screws/washers/sealing tape according to the drawing; no drill debris blocking water.
- Water drains freely, gutters and connectors are not blocked.
- Conduct controlled water tests, observe from indoors, and record leak positions.
Do not step on the daylight sheet
Transparent sheets can be difficult to see on the roof. They must be marked, access restricted, load-distributing platforms and fall protection systems used. Do not rely on the feeling of stiffness or thickness to allow walking.again.
Send roof profile, purlin layout, slope length, and detailed lap photos to receive material specification recommendations before construction.
Send documents to receive reportpriceReference sources and limits of use
- ASTM D3841-21: scope of classification, materials, and testing of fiberglass-reinforced polyester panels used in construction; the standard also notes that specific applications may require different performance levels.
- ISO/CIE 10916:2024: procedure to calculate the influence of daylight on building energy performance.
- MCRMA Technical Paper 1: structure, arrangement, and material selection of rooflight for metal roofing systemtype.
- NZ Metal Roofing Manufacturers – Natural Light Materials: compatible with the profile, characteristics, and differences between GRP and Polycarbonate in industrial roofing.
- Nova Construction Products – Rooflight Application Guide: focal point for guiding rooflight and self-drilling screw installation.
Technical limits: This article is used to screen options and prepare quotation data, not to replace construction drawings, structural calculations, light–heat simulations, fire regulations, or specific instructions for the actual roofing system. All thicknesses, spacing, loads, light transmission, fire resistance, durabilityChemicals, warranty, and price must be confirmed with the factory documentation of the shipment before signing the contract or starting construction.
View the product, material, and specification table at guide to choosing Composite/FRP translucent roofing sheets.
Contact Hưng Thịnh Phát for consultation on specifications and pricing at the factory.
