The aim of this article is to bring together in one place the practical rules for storage, processing and use of PAGED FR fire-retardant plywood so that the user can fully benefit from its properties and avoid common mistakes on site and in production. The following guidance is based on the “Instructions for handling fire-retardant plywood” by PAGED Plywood S.A.
Fire-retardant (FR) plywood is factory-modified to improve its reaction to fire. This modification affects the hygroscopicity of the material – the retardants used may contribute to greater moisture absorption. Good practices for handling wood-based panels include, among other things, appropriate storage conditions for plywood and its conditioning. In the case of FR plywood, this is particularly important, e.g. to avoid salt efflorescence. This will not affect the properties of the product, but may necessitate gentle sanding of the surface before final processing or installation of the panels.
Before veneering, lacquering/painting or installation, acclimatise the panels to the target environment – until they reach a moisture content in equilibrium with the place of use. This step reduces the risk of dimensional changes and unexpected surface reactions during coating.
Two application variants: PO (for veneering/laminating) and PL (for lacquering/painting)
FR plywood is offered in two surface variants. They differ in surface preparation and recommended workflow:
Standard machining operations – cutting, drilling and similar – do not reduce the inherent properties of the panel, but good machining practice is essential to avoid surface defects. Use carbide-tipped (HM) or diamond tools, which minimise edge tear-out and damage.
In FR plywood, fire-retardant additives may migrate towards the surface, creating local discolorations or salt deposits/efflorescence. This phenomenon does not affect the mechanical or fire-retardant performance of the product, but it requires proper handling: light sanding, selection of a suitable coating system and appropriate climatic conditions. Eliminating moisture sources (storage, installation, service) and stabilising the microclimate are the most important preventive actions.
All actions after delivery – sanding, lacquering/painting, veneering/laminating – fall under the responsibility of the purchaser/user. In the case of significant modifications, it is recommended to re-test the reaction to fire, e.g. in the SBI (Single Burning Item) test, and, where justified, to re-assess CE conformity (“Conformité Européenne”) for the finished product.
Does standard cutting and drilling reduce the reaction-to-fire class?
No, basic machining operations do not affect the properties of the panel. What can affect the classification, however, is the subsequent finishing and end-use – these may change the classification if they deviate from the DoP.
What to do if salt efflorescence appears on the surface?
Usually, light sanding and restoring stable humidity conditions is enough. The phenomenon does not reduce mechanical or fire-retardant performance.
Which adhesives are recommended for the PO version?
Preferred: urea- and melamine-based systems, PVC, EPI, PU; proprietary solutions may also be used – in every case, perform a test for the selected adhesive.
When should the adhesion (cross-cut) test be done?
No earlier than 3 days after coating application, so that the result reflects stabilised adhesion.
Which tools should be used for cutting FR plywood?
Recommended: HM (carbide-tipped) or diamond tools, ensuring clean edges and minimal tear-out.
The effectiveness and durability of solutions using fire-retardant plywood depend on consistently following best practice: controlled microclimate, gentle surface preparation, compatibility tests for adhesives and coatings, well-designed expansion gaps and appropriate fasteners. This way you will retain the declared parameters and market-grade aesthetics of the finished product – without unnecessary rework and complaints.
PAGED Plywood S.A.
ul. Mazurska 1, 14-300 Morąg, Poland
For more information and current technical materials, please contact the technical advisor of PAGED Plywood S.A.
Legal notice
The recommendations are for information purposes only and do not replace design documentation, standards or regulations (including fire protection regulations). The manufacturer does not guarantee maintenance of the reaction-to-fire class when the product is used outside the scope of the DoP/DWU or after modifications. All actions performed after delivery (sanding, lacquering/painting, veneering/bonding) are carried out at the purchaser’s/user’s own risk. After significant configuration changes, the reaction to fire of the final assembly must be verified (“tested as used”): EN 13823 (SBI); for flooring EN ISO 9239-1 + EN ISO 11925-2; and, where necessary, the DoP/DWU and CE marking must be updated. Test results and classifications apply only to the configuration actually tested.