SUPALUX®  can be installed in permanently semi-exposed environments providing the boards are not subject to wind-driven rain. When installed in a soffit applications it is expected to have a sufficient drip-edge detail or downstand included to ensure no-wind driven rain tracks along the underside of the ceiling construction.

When installing SUPALUX® in a permanently semi-exposed environment, it is considered good practice to seal all surfaces of the boards prior to installation, in order, to prevent long-term moisture ingress and to prolong the life of the installation.

Further details on finishing and decorating SUPALUX® and other Promat calcium silicate boards can be found within our Technical Data Sheet TDS056. 

In a permanently semi-exposed environment it is common practice to install the boards with butt joints, screwheads filled with Promat MOISTURE RESISTANT READY MIXED JOINT FILLER, lightly sanded and a suitable exterior grade paint finish applied.

SUPALUX® cannot be installed in fully exposed environments and needs to be protected by a metal encasement, cladding board or other system to stop the boards becoming wet.