“MGO board” describes a product family, not one universal recipe. Many boards use a magnesium oxychloride or magnesium oxysulfate binder, with reinforcement and fillers selected for the required density, surface and performance. Buyers should therefore compare the declared formulation and test evidence—not assume that two boards with the same thickness are interchangeable.
Questions to put on the RFQ
- Which binder chemistry and reinforcement are used?
- What are the declared density, moisture movement and dimensional tolerances?
- Has corrosion interaction with the intended fixings or metal framing been evaluated?
- Which test reports apply to this exact formulation, thickness and factory?
- What storage, acclimation, sealing and installation limits apply?
Sulfate does not remove the need for evidence
Sulfate-formulation boards are often promoted for lower chloride-related risk. That may be relevant, but a chemistry name alone does not prove durability, structural capacity, fire resistance or suitability for exterior exposure. Ask for product-specific test reports and quality-control information.
Build a controlled comparison
Compare samples at the same thickness and intended grade. Check cut edges, surface condition, flatness, fastener behaviour and compatibility with the proposed coating or adhesive. For regulated use, the final decision must follow the applicable evaluation report, ETA, certificate or approved project design.