Level 4 vs Level 5 gib stopping: what the difference is and which rooms need it

Level 4 is the standard GIB stopping finish: the joints and fixings are taped and built up with compound, and the rest of the board face is left as it is. Level 5 is everything in Level 4 plus a thin coat of compound over the entire wall or ceiling, and GIB says it should be used where gloss, semi-gloss or dark paints are specified, or where light hits the surface at a shallow angle.

Most rooms in most houses are fine at Level 4. Level 5 is for the walls and ceilings that will be lit or painted in a way that shows everything.

What do the finish levels actually describe?

They come from the joint Australian and New Zealand standard AS/NZS 2589:2017, Gypsum linings: application and finishing, and they describe how much work goes into the stopping, not the quality of the stopper. A Level 4 done well is a good finish. It is just designed for different conditions.

GIB's own description of the two levels:

• Level 4: a base coat of compound with tape in the joint, a second coat typically about 170mm wide, and a final coat no less than 250mm wide on a tapered joint or 500mm on a butt joint.
• Level 5: all of the Level 4 requirements, plus tighter tolerances in framing preparation, back blocking of all joints on walls and ceilings, and an air-drying compound applied over the entire surface, which can be sprayed, rolled or troweled on.

The part people miss is in that Level 5 list. Tighter framing tolerances and back blocking happen before and during lining, not afterwards. Level 5 is a decision you make at the start of a build or reline, not something you can fully add once the board is up and stopped.

Level 4 vs Level 5 at a glance

	Level 4	Level 5
Joints and fixings	Taped and built up in three coats	Same as Level 4
Rest of the board face	Left as paper	Covered with a coat of compound over the whole surface
Framing and back blocking	Standard	Tighter framing tolerances, all joints back blocked
Paint GIB pairs it with	Satin, flat or low sheen, or wallpaper	Gloss, semi-gloss or dark-tone paints
Lighting GIB pairs it with	Non-critical lighting	Critical lighting, even with low sheen paints

Why do raking light and gloss paint expose Level 4?

Because a Level 4 wall is made of two different surfaces: the paper face of the board and the bands of compound over the joints. They are flat to each other within tolerance, but they are not identical. The paper and the compound have a slightly different texture, and the joints are built up and feathered out over a wide band.

Under flat, even light and a low sheen paint, you cannot see any of that. Change either condition and it starts to show.

GIB defines critical lighting as light from windows, skylights or wall and ceiling lights striking a surface at a shallow angle, which exaggerates any surface irregularities. In a house, that looks like:

• A long hallway with a window at one end.
• A ceiling next to a large window or ranch slider, lit by low morning or evening sun.
• Walls with downlights set close to them, washing light straight down the face.
• A stairwell with a skylight above.

Gloss does the same job from the other direction. A higher sheen reflects light like a mirror, so any change in flatness or texture shows up as a wobble in the reflection. Dark colours work similarly, because shadows and texture read more strongly on a deep colour than on a pale one. The wider question of sheen is covered in paint sheen levels explained.

Which rooms genuinely need Level 5?

Apply GIB's two tests to each room: what paint is going on, and how will the light hit it.

• Worth it: the hallway with the end window, a living area with large glazing throwing light across the ceiling, a feature wall in a dark colour, anywhere you intend to use semi-gloss or gloss on walls, and big uninterrupted ceilings with wall-washing lights.
• Usually not needed: bedrooms with ordinary windows and a pale low sheen paint, wardrobes, laundries, garages and most rooms where the lighting is from a central fitting.

That split is why a house can reasonably be specified with Level 5 in a few areas and Level 4 everywhere else. You do not have to do the whole house one way.

If you are keeping Level 4, GIB's advice to homeowners is practical: avoid harsh lighting conditions and choose lighter colours. A pale low sheen paint on a well-stopped Level 4 wall looks very good.

Is Level 5 flawless, then?

No, and it is better to know that before paying for it. GIB itself notes that even Level 5 finishes may show imperfections under critical light. It improves the result a lot. It does not make a wall behave like glass.

GIB also says the accepted way to inspect the finish is standing 2 metres away from the wall under normal lighting conditions, not with a high powered light glancing across the surface. Since a light held flat to almost any stopped wall will pick out something, it is worth agreeing how the finish will be judged before the work starts, not after.

What should you ask for on a quote?

Ask the stopper to state the level for each area in writing, and tell them the paint sheen and colour you are planning. If Level 5 is going into a hallway or living area, check that the builder knows early, because of the framing and back blocking. If you are unsure whether an existing wall needs stopping repairs or a fuller plaster approach, the difference is explained in GIB stopping and plastering, the difference.

For DIY: Level 4 on a small room is achievable with patience. A full Level 5 skim over a whole room is a much harder skill, and it is usually where amateur work shows under the first low sun.

You can see how we approach it on our plastering and GIB stopping page.

If you want an honest view on which rooms in your house need which level, ask us for a quote.