Skimming a wall is a common plastering technique used to create a smooth finish that’s perfect for painting or decorating. Whether you're renovating a room, repairing damaged walls, or simply wanting a fresh, flawless surface, skimming is a great skill to have. In this guide, we’ll walk you through how to skim a wall in the UK, from preparation to final touches, making it accessible even if you’re a beginner.
What Is Skimming?
Skimming is the process of applying a thin layer of plaster to a wall to smooth out imperfections or create a seamless finish over existing plaster, plasterboard, or old textured surfaces like artex. The goal is to achieve a flat, even surface that can be painted or wallpapered.
Tools and Materials You Will Need
Before starting your skimming project, gather the following tools and materials:
- Plastering trowel (ideally stainless steel)
- Plastering hawk (a flat platform to hold plaster)
- Mixing bucket and drill with paddle mixer
- Plasterer’s float
- Plastering angle beads (for corners)
- Multi-finish plaster (for skimming)
- PVA glue (to bond new plaster to old surfaces)
- Bucket trowel
- Plastering sponge or brush (for finishing)
- Dust sheets (to protect your floors)
- Water spray bottle (to keep the plaster damp during the finishing process)
Step 1: Prepare the Wall
Preparation is key to achieving a smooth and long-lasting skim finish. Start by ensuring the wall is clean and free of dust, dirt, or loose plaster. Any cracks or large holes should be filled before skimming.
- Clean the wall: Use a damp cloth or sponge to wipe down the surface and remove any dust.
- Apply PVA glue: If you’re skimming over existing plaster or other surfaces like artex, applying a coat of PVA is essential. Mix the PVA with water at a 1:1 ratio (one part PVA to one part water). This acts as a bonding agent, preventing the plaster from drying too quickly. Apply one coat and let it dry completely, followed by a second coat that is left to become tacky before you start skimming.
Step 2: Mix the Plaster
For skimming, you'll use multi-finish plaster, which is a versatile plaster suitable for a range of surfaces. Follow the manufacturer’s instructions on the packaging to mix the plaster to the correct consistency.
- Mixing the plaster: Pour clean water into your mixing bucket first. Then slowly add the plaster powder, mixing with a drill and paddle until you achieve a smooth, thick consistency, similar to thick cream. Make sure there are no lumps.
- Let the plaster sit: Allow the mixture to settle for a few minutes before mixing again. This will ensure the plaster has a workable consistency and is ready for application.
Step 3: Apply the First Coat of Plaster
Now that your wall is prepped and your plaster is mixed, it’s time to start applying the first coat of plaster. The aim of this coat is to cover the wall evenly and build up a smooth surface.
- Load your hawk: Use your bucket trowel to scoop plaster onto the hawk.
- Apply plaster to the wall: Holding the hawk in one hand and your trowel in the other, transfer plaster from the hawk to the wall using the trowel. Start at the top of the wall and work your way down in smooth, sweeping motions. Aim for a thin coat (around 2-3mm thick).
- Spread evenly: Keep the trowel at a slight angle (about 10-15 degrees) and apply even pressure as you spread the plaster. Try to avoid leaving ridges or thick patches.
- Work in sections: Plaster dries quickly, so work in manageable sections. Once you’ve covered the wall, use your trowel to smooth out any uneven areas or lines.
Step 4: Apply the Second Coat
The second coat of plaster is applied while the first coat is still slightly damp. This coat is usually thinner (about 1-2mm) and serves to refine the smoothness of the wall.
- Mix a new batch of plaster: Prepare a fresh batch of plaster as described earlier.
- Apply the second coat: Repeat the process from step 3, but apply a thinner coat. This coat should be even smoother than the first and will fill in any remaining imperfections.
- Smooth out: As with the first coat, use your trowel to smooth out the plaster as much as possible, aiming for a flat and seamless finish.
Step 5: Trowel and Polish
Once the second coat is applied, you’ll need to smooth and polish the wall before the plaster fully sets. Timing is crucial at this stage; you need to wait until the plaster has firmed up slightly but is still damp enough to work with.
- First trowel: As the plaster begins to set (about 10-15 minutes after applying the second coat), use a clean, damp trowel to smooth over the surface. Hold the trowel at a shallow angle and apply light pressure. This will remove any minor imperfections or lines.
- Polishing: After about 30-45 minutes, the plaster will be firm but still slightly damp. Use your trowel to polish the surface. Lightly wet the wall with a spray bottle and gently smooth over it with the trowel to achieve a polished, glass-like finish.
Step 6: Finishing Touches
Allow the plaster to fully dry before painting or decorating. Depending on the temperature and humidity, this could take anywhere from 48 hours to a few days. Once dry, the wall should be smooth, even, and ready for any finish you choose.
- Painting or wallpapering: Before applying any paint or wallpaper, it’s best to apply a mist coat—a watered-down emulsion paint (usually a 50:50 mix of water and paint) to seal the new plaster. This will prevent the final paint coat from soaking into the plaster and will give you a longer-lasting finish.
Common Mistakes to Avoid
- Rushing the process: Skimming requires patience. Make sure each coat is applied evenly, and allow sufficient drying time between stages.
- Skipping PVA: Without PVA, the plaster won’t adhere properly to the wall and may dry too quickly, leading to cracks.
- Overworking the plaster: Once the plaster begins to set, avoid over-trowelling, as this can lead to an uneven surface.
Conclusion
Skimming a wall may seem daunting, but with the right tools, materials, and technique, it’s a job that can be done by beginners with some practice. A well-skimmed wall provides a perfect base for painting or wallpapering and can dramatically improve the look of any room. By following this guide and taking your time, you’ll achieve a smooth, professional finish that lasts for years.