Having cracks or holes in the wall is not uncommon. When walls undergo stress due to external factors, it is no surprise they react to this challenge. Especially for older homes, their old composite may have been getting brittle or forming cracks with the wooden lath showing up from beneath.
When the cracks or holes are small, you may not need to call the plaster experts. You can repair and patch these small holes and make them look new. Use plaster to fill them up and sand them smooth until they are ready for painting.
What is Plastering?
Plastering is applying a layer of plaster to walls or ceilings to make the surface smooth, even, and finished. This method covers damaged surfaces and imperfections, enhancing the wall’s durability and readying surfaces for decorative finishes.
When to plaster a small area?
- When there is significant damage or gap in the wall
- The wall surfaces are rough and uneven
- To prepare the surface for painting or wallpaper
- For renovation projects
- For maintenance
What are the Challenges of Plastering a Small Area Only?
When plastering to a small area only, you must be aware of the possible risks. If you are working on a cracked surface, you must identify if it is not a result of structural problems.
Another challenge with plastering on a small surface is keeping the surface smooth and even. Feathering and blending is also one thing you must focus on. You want the plastered surface to be as seamless as possible. It is easy to spot a plastered wall because it is noticeable.
Also, a smaller area has reduced airflow. You need to give the plaster enough time to dry before using the plastered wall for painting or decoration.
The entire process could be messy. You will be dealing with plaster spills and splatters, so you need to protect the objects around and nearby.
Things to prepare:
- Putty knife or scraper
- Diluted PVA glue
- A paintbrush
- A plaster trowel
- A hawk board
- A bucket trowel
- Mixing bucket (If the plaster is not premixed)
- Sandpaper and sander
- Safety goggles
- Dust mask
- Protective gloves
How to Plaster a Small Area on the Wall?
If all the tools and materials you need are ready, you can begin preparing the area and the wall for plastering a small damaged area.
Step 1 Prepare the wall.
The first stage of preparing for plastering is clearing your area. Remove all the furniture that might catch the plaster and debris from loose wall parts. Place a drop cloth or dust sheet under the wall for plastering.
Remove the loose areas, paint, dust, and debris. Your wall should be dust-free so the plaster can adhere to the wall. So use your putty knife or scrape to remove chipped-off paint. Use a brush to remove dust thoroughly.
Cover cracks and holes with screen tape. Cover the plasterboard joints with screen tape if you are plastering to a new wall.
Step 2 Apply PVA glue.
The next step is to apply PVA glue. This process will help improve adhesion. And since being dust-free is integral to plaster adhesion, PVA glue will help seal the surface from dust and debris.
Also, PVA glue will reduce moisture suction by porous types of walls. Porous walls dry the plaster easily, resulting in uneven drying and preventing the plaster from adhering properly.
Use only diluted PVA glue. Check for the manufacturer’s procedure. But in general, the ratio of the diluted PVA is one part glue and four parts water.
Use a roller or brush to apply PVA evenly.
When the glue feels tacky, you can apply plaster on the wall.
Step 3 Mix the plaster. (Skip when you have a premixed plaster)
If you do not have a premixed plaster, you can mix it yourself. Check the label for instructions. Before mixing plaster, make sure you are wearing a dust mask.
Pour the continents into a clean bucket and follow the instructions in the manual. Gradually pour plaster powder.
Whisk and stir accordingly until the plaster has a consistency of a paste or a thick custard. Do this until you find no signs of lumps or dry air pockets. Let the mixture rest for a few minutes to absorb the water. Then mix again.
The final consistency should be creamy and workable. It should not be too thick or too runny. It must hold its place on the trowel without sagging or dripping.
Step 4 Apply the plaster.
For small areas, a hawk board should hold your plaster. With your trowel, scoop a small amount of plaster first (if you are not comfortable or if it’s your first time) and place it in your hawk board. With your plastering trowel, pick a small amount of plaster from the hawk board and spread it on the gap upward and outward with the trowel angled a bit away from the wall.
At each end of the stroke, add more pressure to the trowel and flatten the plaster to smooth it out.
Place small amounts of plaster each time on the hole or crack. From the bottom left, spread it upwards and outwards firmly. Keep plastering this way until you spread it evenly and smooth it out.
Step 5 Smoothen the surface.
After applying the first coat, let it dry for about twenty minutes. Then proceed to press the trowel again and smoothen out the surface. Get rid of those lumps and bumps. You can do this better by spraying the plaster with water to soften it. This way, it can respond to the trowel directions. Focus on the edges and corners of the plaster. If needed, use a paintbrush to spread it evenly.
Step 6 Scrape the wall.
Before applying the second coat, you need to scrape the excess plaster. This will help the second coat of plaster adhere to the first coat. You can easily do this with a deviling float or a kitchen fork.
Step 7 Apply the second coat.
You must thin the second coat by diluting it with a thinner or water. Your first coat must still be wet when applying the second coat. The idea is to apply a thinner coat not thicker than 2 mm. This should help you even and smoothen it out easier. You need to spread the plaster at least three inches from the hole or crack.
Step 8 Apply finishing touches.
When applying finishing touches, the surface must still be damp. Spray water on the edges of the plaster to make it soft. Smoothen the surface with the trowel by making inward strokes. Let it dry overnight.
When the plaster has dried completely, you can now sand the surface. Start with coarse grit and finish it off with fine grit. This process should rid excess plaster bumps on the edges, smooth imperfections, blend into the existing wall, and prepare the surface for painting or sticking wallpapers.
Step 9 Prime the surface before painting or hanging wallpaper.
When the plaster has dried, you can paint over it or decorate it with wallpaper. However, you must prime or apply an undercoat before painting the surface. Otherwise, the paint will only sink into the surface. The process will seal the plaster and serve as the bond with the paint.
After drying for twenty-four hours, you can apply the undercoat. Make sure the surface is clean and dust-free before applying. Use a brush or roller to apply the undercoat. Depending on the product, you may need to dilute the primer. Let it dry according to the manufacturer’s instructions before painting.
If you will cover the wall with wallpaper, you also need to prime it with an undercoat or a wallpaper adhesive. Apply at least two coats of wallpaper adhesive, and let it dry before spreading the wallpaper on the wall.
More Tips for Patching a Small Area with Plaster
- Wear dust masks, safety goggles, and safety gloves.
- Use a shop vac to clean the dust.
- Fix the leaks beneath the walls before plastering.
- Your ideal temperature before and during plastering is between 55 to 70° F.
- Make sure the walls are fully dry before working.
- Use a small trowel and plastering knife for a more efficient job.
- Multiple thin coats are better than a single thick coat.
- Focus on your feathering technique.
- Aim for consistent texture.
- Practice in a small inconspicuous area.
When to not Patch on a Small Area?
While patching with plaster is a common practice for repairing, there are some instances wherein it is not advisable.
- When there is an extensive damage
- When the surface is wet
- When there are moisture and leakages
- If the wall has an unstable substrate
- If the small area on the wall has an existing specialized texture or finish that you want to preserve.
Final Thoughts
Plastering a small area can be easy if you use the appropriate techniques. All it takes is careful surface preparation so the plaster will adhere well. Next, you should know what and how to use the right tools. Sometimes spreading the plaster could be a challenge. Feathering and blending are specialized techniques you must learn to create a seamless plaster. With a little attention to detail, you can easily pull off a plastering job on small areas.
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