16/10/2026
South African construction teams need to know how to seal MGO boards before exposing them to demanding outdoor conditions. Coastal humidity, intense sunshine and wind-driven rain place different pressures on building envelopes. However, lasting protection depends on more than applying paint to the visible surface.
Magnesium oxide boards support applications ranging from lightweight wall systems to modular buildings and soffits. NLA specifically advises that its MGO boards must be painted and sealed to withstand moisture and extreme South African weather. Consequently, contractors should include surface preparation, compatible finishes and weatherproof detailing in the original specification.
Why weather protection starts with the building system
Water resistance does not mean that a board can remain indefinitely exposed without protection. Moisture can enter through unfinished edges, poorly detailed openings and damaged coatings.