13 Dec Painting Plasterboard

DID YOU KNOW

Subject: Painting

Bare plasterboard should be painted as soon as practicable in order to prevent discoloration of the paper surface which can migrate through water borne paint coatings.

As per AS/NZS 2311:2017 (Guide to Painting of Buildings) a quality sealer undercoat of adequate (DFT) dry film thickness should be applied in order to satisfy the variation in porosity of the plasterboard paper face, jointing and stopping. The sealer / undercoat also aids in blocking migration of impurities from jointed substrate through the paint coatings minimizing issues such as “sheen staining”/ “gloss banding”.

It is recommended that once the first coat of sealer is allowed to fully dry a visual inspection of the plasterboard surface is conducted. A visual inspection of the plasterboard surface should be carried out under natural diffused daylight (non-glancing), viewed at an angle perpendicular to the surface and from a distance of 1.5 mtrs as per AS/NZS 2589:2017 and Fair Trading “Guide to Standards and Tolerances”.

The visual inspection process or (markup) is conducted to identify any remediation work required such as tool marks, pin holes, unsanded edges or scratches prior to applying finishing coats and should be circled lightly (in pencil)

After sanding and dust down of any required patching, a coat of sealer should be applied over the bare plaster patching with a small roller and blended out in order to emulate the surrounding surface texture.

Lightly sand the entire surface (de nib) when dry, dust down and apply finishing coats to paint manufacturers recommendations.

Paint and Plasterboard manufacturers, AS/NZS2311:2017 & AS/NZS 2589:2017 recommend back rolling coats when applying paint with airless spray equipment.

Back rolling all coats while wet is deemed as “best practice” which imparts a slightly stippled texture to the paint coating assisting in paint coverage, touch ups and minimizing light reflection from the surface enhancing visual uniformity.