Finishing a plasterboard wall is intended to prepare the wall for painting. The procedure is simple and consists in sealing the joints between the panels that form the wall by spreading paper tape on the joints, after which the special filler must be applied and sanded to obtain a perfectly smooth surface. Even if you don't need special tools or complicated procedures, to get good results you still need attention and patience. Even a beginner can make a good drywall finish by carefully following the necessary steps. This article tells you how.
Steps
Method 1 of 3: Apply the first coat of putty
Step 1. Make sure the wall is ready to be treated
After the installation step, check if there are any screws protruding from the surface. Screw them tightly making them sink a little into the wall. If some parts of the covering paper of the panels have come loose and hang, remove them so that they are not an obstacle to the application of the grout.
Step 2. Mix the grout
The specific plaster for plasterboard is sold in bins. Remove the lid and see if there is a layer of water on the surface of the product. If there is, mix the product well, possibly helping with an electric drill to which you will have applied an accessory to mix. If there is no water, it is not necessary to mix.
Step 3. Fill the nail and screw heads with putty, and apply it to the cracks between the panels
Use a 12 cm spatula. Close the gaps between each panel with putty. Also cover the screw holes well.
After covering all the cracks and screws, pass the trowel over the grouted areas to smooth the surface. The better you can smooth the grout now, the less effort you will have later when applying the second and third layers of grout
Step 4. Apply masking tape to all joints
Unroll some tape and place it on top of the fresh grout covering all the joints. Gently press the tape over the joints. Unroll some more tape and go on covering the joints until you get to the bottom of the wall. Help yourself with the spatula blade to cut the ribbon precisely.
When you need to put the ribbon in an inner corner, prepare the crease first. Cut a length of ribbon to the right length and then fold it back to form an angle. Apply the tape in the corner pushing it in well with the help of the spatula
Step 5. Smooth the tape with the putty knife
Keep the putty knife almost resting on the tape covering the seam, so that it forms a sharp angle to the surface. With a smooth motion, drag the trowel along the joint, pressing the tape onto the grout. Scrape off the excess grout.
Step 6. Cover the edges with putty
Do not put the tape on the outer edges, as these must be protected with corner profiles. Grout both sides of the protection profile, smoothing the grout with a coat of a spatula.
The edge protectors, in metal or plastic, have a standard length of 3m, so you will need a pair of tinsmith scissors to cut them to size. They are very useful for protecting edges and preventing damage over time from impacts and the like
Step 7. Let the grout dry for 24 hours
At this point, after applying the first layer of putty, the plasterboard wall will still appear rather uneven. Don't worry if the paper tape remains partially visible or if you notice that the various areas of the wall have a slightly different texture. However, you will need to apply at least another layer of putty: soon these imperfections will be resumed until they disappear completely.
Step 8. Sand the filler layer
After letting it dry for at least 24 hours, smooth the surface by sanding it gently. Use medium-grit sandpaper and be careful not to have a heavy hand. Putty is a not very resistant material: if you sand too hard it comes off easily and the paper tape is damaged.
Use a sanding block for the inside corners, while you may find it convenient to use a long-handled sander for sanding edges and joints
Method 2 of 3: Apply the second layer of putty
Step 1. First scrape the wall with a 15cm putty knife or scraper
The scraping is used to eliminate any residues or stucco smudges left over from the previous phase. This makes it easier to apply the second layer of putty, which will be more homogeneous, helping to give your finishing work a professional look.
Pay special attention to places, such as edges or bottom corners of the wall, where debris tends to accumulate
Step 2. Use a 25 or 30 cm scraper to treat the joints where the tapered edges of the panels meet
There a small indentation is created in the wall. The good thing is that gaps can be easily filled with putty, as opposed to protrusions which are much more difficult to remove.
Simply take a 25 or 30 cm wide putty knife and spread a thin layer of putty in a straight line. 25-30 cm is approximately the width of the area to be trimmed at the seams of the tapered edges
Step 3. At first use a narrower spatula, then move on to using gradually wider spatulas up to 35 cm, to treat the joints between the square edges of the panels
Unlike the commissure between tapered edges, where a recess is created in the wall, the commissures between square edges are more difficult to mask. This is due to the fact that the paper tape spread over it creates a kind of thin protrusion, which must be hidden by spreading the putty on a wider strip so that the surface appears uniform.
- Find the center of the commissure. Start spreading the grout with a 20 cm spatula. Gradually increase the width of the trowel up to 35 cm, always continuing to work on the same side of the corner.
- Putty on the other side, again starting with the 20 cm trowel up to the 35 cm one.
- Eventually you will find yourself having a 60 to 70 cm wide strip of stucco straddling the corner along its entire length.
Step 4. Use a 6 '' putty knife to treat the edges
Spread the grout only on one side of the edge and let it dry for a day. Once dry, finish the other side of the edge with the spatula. If you try to finish both sides on the same day you will see that when you press the putty knife on one side you ruin the work done on the other, because the filler is still soft and gives way under the pressure of the putty knife.
Alternatively, you can use an edge trowel instead of refining the edges separately. An edge trowel is a shaped trowel that has a 90 ° notch, perfect for finishing a right-angled edge. To use this tool well, however, it is necessary to acquire a certain dexterity
Step 5. Sand the second layer of putty
After 24 hours, sand it gently to smooth it out. Use fine-grit sandpaper, and keep your hand light. The purpose is only to smooth the areas where the grout appears coarse, not to dig into it.
Method 3 of 3: Apply the third layer of putty
Step 1. Again start from scraping
With a small spatula or scraper, go over the grouting from the day before and remove any residues or smudges left. 15 to 20 minutes of scraping can make a big difference in the final result.
Step 2. Apply the third (and last) layer of putty
Without this third layer, you risk having areas without stucco and others where the stucco is quite thick (for example on the joints between square edges). Areas without grout will be different to the eye and to the touch than those in which the grout is present. The third layer eliminates this problem, ensuring uniformity across the entire wall.
Step 3. Apply some light filler all over the wall with a thin roller
Dip the roller in the semi-liquid putty and pass it on the wall, working in strips. In reality, rather than rolling, the roller should crawl across the surface thus distributing the grout.
- When you roll the putty on the wall with the roller, start from the bottom and work your way upwards. This will prevent the grout from dripping onto the floor.
- Divide the work area into vertical strips that are not too wide. In reality, much of the putty applied in this pass has to be removed and if the work area is too large it will eventually dry out before you can remove it.
- Abound in the amount of putty. If the grout layer is too thin, it tends to dry out too soon. This would make it difficult, if not impossible, for you to remove it.
Step 4. Leave the edges alone, but be sure to treat the commissures
The edges are already covered with putty, so there is no need to add more. Instead we want to hide the joints, and adding more filler on top can be useful.
Step 5. Remove as much grout from the wall as possible, working in strips
With a large putty knife, scrape off as much putty as you can. You are not plastering a wall or giving an exterior finish: your goal is to make the wall look homogeneous by means of a thin layer of stucco.
Step 6. Go on like this, applying and removing strip putty
Treat the entire wall like this. At the end let it dry for 24 hours, then fine sand one last time and your wall will be ready to be painted.
