This article contains information about skim coating and decorating GIB Plasterboard.
 

Please go to the article titled, Jointing GIB Plasterboard to find information about finishing edge joints, end joints and for advice on dealing with corners.

 

Skim Coating
 

Skim coating involves covering the entire plasterboard surface with a thin layer of finishing material to give a smooth, consistent texture across both joints and the paper surface of the plasterboard.
 

As stated in the introduction if this is being done to cover old walls then it is recommended that you remove the old linings and start afresh. This method typically costs only a little more than skim coating the old plasterboard but has many advantages.
 

If skim coating is the only option for you or you have a special requirement for a very smooth finish such as in a critical light area then it is recommended that a tradesman is used. Walls must be prepared in different ways depending on whether it is new plasterboard, has been painted, has had wallpaper or even if the plasterboard is old. A tradesman will be aware of the correct way of preparing the wall to reduce the risk of problems into the future.

Checking the Jointing
 

The quality of the final decoration is dependent on the quality of the jointing. Using Table 4, inspect the quality of the jointing prior to decoration.
 

Tip: Imperfections will be easier to see by shining a light, such as a torch, along the wall. 

This will show up any imperfections as shadows.
 

Table 4 - Checking the Jointing

Paint Decoration
 

There is plenty of information available on painting plasterboard, however, the following guidelines give a summary of best practises.
 

	Once the GIB has been properly finished and is dry, apply a sealer undercoat first. Ask in the paint department of your local Mitre 10 store.
	Use flat paints rather than semi-gloss or gloss where possible. Gloss paints will reflect light to varying degrees, exaggerating surface imperfections.
	Light colours tend to diffuse light helping to disguise any surface imperfections. If it is intended that dark colours will be used then it is recommended that the services of an experienced tradesman be sought.
	Avoid the use of harsh lighting such as wall washers or creating situations that give harsh light such as windows extending to a wall or ceiling line. Where `harsh` or `critical` lighting conditions occur, i.e. where the dominant light source shines across the surface, imperfections will be easily seen. Consider skim coating the wall or applying a wallboard prep coat.
	Use water based paints, except in wet areas, as these will make it easy to create an `orange peel` effect which helps to disguise any imperfections.
	`Cut in` around edges and doors with a paint brush and then apply the remainder of the paint system using a medium to long nap roller (7-20 mm). This will aid in creating a soft `orange peel` effect.
	Always maintain a `wet edge` with the roller and apply the last coat with the roller marks in the same directions and parallel to the dominant light source.

Paint systems should always be applied in accordance with the manufacturer instructions.

 

Wallpaper Decoration
 

It is important that an oil-based sealer is applied to the surface prior to wallpapering. Some wallpapers are quite thin and the joint may telegraph through due to differences in porosity between the joint and the plasterboard surface. This also aids in the removal of the wallpaper at a later date if redecoration is required.