Fertiliser stores and rice mills in Laos lose metal roofs early because fertiliser dust absorbs moisture and forms a corrosive film on steel. ASA/PVC roofing sheets are not attacked in the same way and do not rust, and a cooler roof, about 6 – 8 °C cooler underneath than bare metal, reduces condensation that can wet stored rice.
Why do metal roofs fail in fertiliser stores?
Fertiliser dust settles on purlins and the underside of sheets, takes up moisture from the air and keeps the metal wet. The zinc coating goes first, then the steel. Screw holes and laps fail before the rest of the sheet.
ASA/PVC sheets on a working building
Keeping stored rice dry
- Choose the 6-wave sheet, with 34 mm ribs, so heavy rain stays in the channels.
- Fix screws through the top of the wave, never in the trough.
- Ventilate at the eaves and ridge to reduce condensation.
- Add skylight sheets only where people work, not over stored rice in direct sun.
What about the purlins?
Steel purlins in fertiliser stores need regular painting. FRP composite purlins from Santiago do not rust and come cut to length with stainless fittings.
Importing to Laos? Delivery by truck from Vietnam, minimum one 40 ft load (about 5,000 m), production about 5 days, Form D included: importer and distributor guide.
Santiago – a leading exporter of ASA/PVC roofing from Vietnam
Santiago roofing is produced and loaded into containers at our factory in Vietnam. It has been exported to India since 2023, Thailand since 2024 and the USA since 2025. Every export shipment comes with a commercial invoice, packing list, bill of lading and a certificate of origin (C/O) issued by Vietnam's Ministry of Industry and Trade, which importers use to claim the duty preference of their trade agreement.
| Item | Details |
|---|---|
| HS code | 3925.90.00 (ASA/PVC roofing sheets) |
| Certificate of origin | Form D (ASEAN), Form AI (India), Form AK / VK (Korea), Form AJ / VJ (Japan), Form VC (Chile), CPTPP proof of origin |
| Shipped from | Vietnam, by container |
Certificate of origin Form AI (ASEAN–India) for Santiago ASA/PVC roofing sheets, HS 39259000, certified on 24 September 2026. Buyer details are hidden.
The Santiago team beside a loaded export container at the factory, November 2024
Loading Santiago roof tiles into an export container
Frequently asked questions
Do plastic roof sheets resist fertiliser dust?
They do not rust, so fertiliser dust does not corrode them as it does steel.
How do I stop condensation in a rice store?
Use a cooler roof material and ventilate at the eaves and ridge.
Which purlins suit a fertiliser store?
FRP composite purlins, which do not rust, or steel purlins painted regularly.
Related products: ASA/PVC 5 waves · 6 waves · 11 waves · ASA/PVC roof tile · Skylight sheets
Contact Santiago: Santiago Import Export Co., Ltd, Vietnam. WhatsApp +84 935 391 495 (Mr. Quyen), hotline +84 965 437 316 (Mrs. Ly), email salessantiagoroofing@gmail.com.
Updated October 2026.
