Things to consider when replacing plasterboard
The level of difficulty replacing the water damaged board will be determined by accessibility, how many layers and if it’s a “performance” system. Keeping in mind a “performance” system is dependent on the individual GIB® components to remain dry in service to remain effective for the life of the building – typically 50 years according to the building code.
If it is a bracing element, the minimum size part sheet in a Brace wall is 300mm so at a minimum, you will need to replace the bottom 300mm. Where sheet butt joins occur, it is best practice to back-block with GIB® Cove Bond®. All joints must be taped and stopped as per GIB® Site Guide.
If it is a Fire wall, all sheet edges/joints usually must be fixed on a solid member as a minimum* (stud or nogg). If there are 2 or more layers on one side, these layers must be overlapped by a minimum of 150mm and the sheet edge of each layer must have it’s own solid fixing.* Again, all joints on the outer layer must be taped and stopped as per GIB® Site Guide.
If there is any mould on the face of the board, this can sometimes be dealt with by killing the bacteria by using a suitable chemical such as bleach, but care must be taken to not damage the paper back/face. Please be aware that mould spores can sometimes be deeply ingrained in the core and ‘survive’ cleaning, so this is definitely not the preference.
In addition, to achieve the optimal quality of the overall finish, the stopping compound, paper face and gypsum core need to be “as new”, the timber framing needs to be fully dry to avoid future screw popping, which can sometimes happen as long as 6 months after the wall was lined. This is generally due to timber drying and shrinking.
Finishing
Adjacent surfaces need to be free of loose paint/wallpaper. The sheet joint and any large voids, can then be filled and taped with a GIB® air drying compound such as GIB® Plus 4. Once dry, top coat with an Air drying compound like GIB Plus 4® then follow with a good sealer and paint.
*Check the relevant System Literature for details.
The GIB® Site Guide contains all the information you’ll need to replace damaged board.
For more info visit gib.co.nz or call the GIB® helpline on 0800 100 442
