Painting a room seems simple until you run out of paint, the color looks different on the wall, or the tape pulls off part of the finish. Rushed preparation can also leave marks, uneven edges, and small imperfections visible under the new paint.
PaintUber sells mineral paint kits to individuals, with paint and tools in a single box. Even so, a good result depends on measuring, checking the wall, and following the correct application order.
Quick answer: how to paint a room step by step
This is the complete order for painting a room yourself:
- Check the walls and fix any dampness or imperfections before painting.
- Calculate the wall area in square meters and divide the surface area by 5 to find the number of liters needed.
- Choose the color and test it directly in the room if you have any doubts.
- Remove or move the furniture and protect the floor, baseboards, outlets, and frames.
- Clean the surface and fill holes or loose areas.
- Mix the paint and cut in the corners and edges with a brush.
- Apply the first coat with a roller without leaving puddles.
- Wait between 2 and 4 hours and apply the second coat.
- Carefully remove the tape and allow the full 24-hour drying time to complete.
For example, we will follow a room intended for teleworking with 20 m² of paintable wall. The surface is firm, has some signs of use and small holes from old pictures, but shows no dampness. For two coats and a reasonable margin, it needs 4 L of paint.
1. How to check a room before painting
Start by inspecting each wall in good light. Look for peeling paint, chips, cracks, holes, stains, adhered dust, and areas that appear damp. Gently run your hand over the surface to check if it sheds material.
Do not cover an active problem expecting the paint to hide it. If there is a leak, rising dampness, or structural chipping, paint will not fix it. First, you must identify and resolve the cause. Painting over it only postpons the problem and can cause the finish to deteriorate again.
Condensation also requires a prior diagnosis. It can appear due to a combination of water vapor, cold surfaces, and insufficient ventilation. This guide on what to do before painting a wall with condensation explains how to distinguish that case from a leak or dampness rising from the lower part of the wall.
In the example of the teleworking room, the dark marks disappear after cleaning and the existing paint remains adhered. This allows you to continue. The holes from the pictures must be corrected because a new layer of color will not fill them.
Also check if the previous color is uniform. A wall with patches, repairs, or areas that absorb differently may need more care during preparation. Do not add water or modify the paint to compensate for it yourself. Always follow the instructions on the container label.
2. How to calculate how much paint you need for a room
Measure the surface area of the walls, not the floor area. For each wall, multiply its width by its height and add the results. If you are going to paint the ceiling, calculate it separately by multiplying its length by its width.
Then you can subtract doors and windows. In a room with many small cutouts, it is also reasonable to keep part of that surface area in the calculation as a margin for edges, absorption, and normal losses in the tray and roller.
To buy without depending on the most optimistic end of the yield, calculate 5 m² per liter for two coats. The product sheet indicates a yield of 10 to 12 m² per liter and coat, but the reference of 5 m² per liter already accounts for both coats and leaves a margin.
The practical formula is this:
Liters needed = paintable surface area in square meters ÷ 5
In our example, there are 20 m² of wall. The calculation gives 4 L to apply two coats. If the surface were about 10 m², it would correspond to 2 L.
| Wall area | Paint for two coats | Estimated kit format | What the calculation includes |
|---|---|---|---|
| About 10 m² | 2 L | 2 L kit | Two coats with margin |
| About 20 m² | 4 L | 4 L kit | Two coats with margin |
Do not confuse the yield per coat with the total amount of work. This mistake leads to buying as if only one layer were going to be applied. The first coat may look sufficient while it is wet, but as it dries, differences in tone, touch-ups, and areas with different coverage usually become noticeable.
If you want to check the measurement in more detail, consult the guide on how much paint you need for a room. Note down the walls and ceiling separately so you do not mix surfaces that you may paint in different colors.
3. How to choose and test the color before painting the room
The color seen on a screen is not subjected to the light in your home. The orientation of the room, artificial lighting, the floor, and the furniture modify how it is perceived. A small sample on a card also does not show how the color will respond on a large surface.
Test the shade directly on the wall when the choice is not clear. PaintUber offers a 100 ml paint sample to make this check before ordering the final format. All colors on the card cost the same, with no surcharge for the shade.
Apply the sample in an area where you can observe it in the usual light of the room. Do not decide just after finishing painting it. Look at how it is perceived at different times and next to the elements that will remain in the room.
In the example room, the first shade chosen seemed suitable on screen, but it looked too dark during the afternoon. The test allowed changing it before buying the 4 L. That small step avoided painting two coats of a color that did not work in the space.
If you are comparing several options, change the location of each sample or leave separation between them. Placing shades next to each other makes them influence each other. The guide on how to test paint samples on the wall develops this process without depending solely on the screen.
4. How to prepare the room for painting without making a mess
Remove everything from the room that you can easily move. Take the remaining furniture toward an area that allows you to access the walls and cover it. The goal is not only to avoid drips, but to be able to work without stretching your arm over obstacles or brushing against a freshly painted wall.
Spread the drop cloth over the floor and make sure it reaches the edges. The PaintUber kit includes a 3.74 x 3.74 m plastic sheet. If the space or layout leaves any area out, protect it before opening the paint.
Place painter's tape on baseboards, frames, and elements that you are not going to remove. Press the edge that is next to the painted surface to reduce leaks. Do not use the tape as a substitute for a controlled cut with a brush. Its function is to protect, not to correct an excessive load of paint.
Before starting, leave a stable spot clear for the tray and prepare an exit route. It seems like a minor detail, but it avoids stepping on the plastic with paint or having to cross the room carrying a full tray.
If you are also going to paint the ceiling, start with it. Then continue with the walls. This way you can correct any brush or splatter produced during the work on the ceiling in the upper part.
5. How to prepare a wall before painting
Paint needs a firm, clean base without loose material. Remove dust and cobwebs, especially in corners, baseboards, and joints with the ceiling. Clean stains compatible with a superficial cleaning and let the wall dry before continuing.
Correct holes and defects with a material suitable for the specific repair, respecting its instructions for use and drying. When the repair is ready, level the relief and remove the generated dust. Do not paint over sanding residue because it can mix with the paint and leave an irregular texture.
Areas with peeling paint require first removing what is not well adhered. Painting over it can hide the edge while the layer is wet, but it does not make the underlying material firm again.
In our example, signs of use are cleaned and holes from old pictures are corrected. Then the wall is checked against the light. A small burr that was barely visible from the front cast a clear shadow, so it was leveled before opening the paint.
Dedicate time to this inspection. A matte wall can hide part of the irregularity, but it does not make holes, cracks, or reliefs disappear. You can expand this step with the specific guide on how to prepare a wall before painting.
6. How to cut in corners and edges with a brush
Open the container when the room is already protected and the wall prepared. Mix the paint until the content has a homogeneous appearance. Avoid shaking it roughly if that incorporates air, and do not dilute it out of habit. The valid reference is the container label.
Start cutting in with a brush the joints where the roller cannot work with precision: corners, ceiling line, frame contours, and the area near the baseboards. Load the brush without soaking it up to the handle and spread the paint in a wide enough strip to later bring the roller close.
Move forward in parts. If you cut in the entire room and take a long time to pass the roller, the edge can dry before the rest. That increases the possibility of noticing a difference between the area applied with a brush and the area applied with a roller.
In the 20 m² room, it is advisable to cut in one wall and then pass the roller over that same wall. Then repeat the sequence. This way, a controllable pace is maintained for someone who is painting their own home.
Do not load paint against the tape. A thick accumulation forms an edge that can break when removing it. Work with a regular layer and let the brush do the cut in, without depending on a saturated tape barrier.
7. How to apply the first coat of paint with a roller
Pour a manageable amount into the tray. Load the roller and spread it over the slanted area before taking it to the wall. If it drips when you lift it, it has too much paint.
Apply the first coat in adjacent areas and maintain a wet working edge. Spread the paint, distribute it, and finish with soft passes that leave a regular texture. Do not keep going over an area that is already starting to dry. The roller can lift the material or produce marks with different shine and relief.
Maintain a stable pressure. Squeezing too hard to squeeze the roller does not make better use of the paint and usually marks the sides. Reload when you notice that it stops spreading a uniform film.
Work the entire wall before stopping. Stopping in the middle and continuing when one part has already dried can leave a visible joint. Corners offer more discreet cut-off points.
PaintUber mineral paint is a water-based paint with a load of calcium carbonate CACO3®. It is breathable, so it allows water vapor from the wall to pass through.
It also appears without hazard indications according to the CLP Regulation 1272/2008, the European standard that regulates the classification, labeling, and packaging of substances and mixtures. This does not replace reading the label or the normal precautions when painting.
8. How to apply the second coat without leaving marks
The paint is dry to the touch in 1 hour, but you must wait between 2 and 4 hours before applying the second coat. Do not use the superficial touch as the only signal to advance the repainting. Respect the indicated interval.
Take advantage of the wait to check the room without touching the walls. A first coat can show apparently uneven areas during drying. Do not correct isolated points immediately. Wait for the second coat and work the entire wall again.
Repeat the same order: cut in the edges of an area and continue with the roller while that cut in is still fresh. Maintain a regular load and avoid going back over parts that are starting to set.
In the example, the first coat leaves part of the previous shade visible near a repair. An isolated patch is not applied. The second coat is spread uniformly over the entire wall, which evens out the color and texture.
The total drying time is 24 hours. During that period, avoid leaning furniture, sticking elements, or cleaning the surface. The fact that it is dry to the touch does not mean that it has completed the process.
The paint has zero yellowing, is very washable, and does not crack. When the time comes to clean signs of use, act in a controlled manner and without rubbing aggressively. This guide on how to clean a painted wall without damaging the finish explains the subsequent maintenance.
9. How to remove the tape and check the finish
Remove the tape carefully, without pulling it abruptly in a direction perpendicular to the wall. Do it progressively and watch the points where paint has accumulated. If the edge offers resistance, do not pull hard because you could lift the adjacent finish.
Check the room with frontal and side light when the paint has dried. Side light reveals reliefs, thick edges, and roller marks that go unnoticed from the front. Do not confuse an area that is still drying with a permanent defect.
Check especially the joints with the ceiling, baseboards, and frames. If you detect a small flaw, wait until the paint is in conditions to be handled and correct it with a controlled amount. A large touch-up over an already uniform wall can be noticed more than the original imperfection.
Collect the tools following the instructions applicable to water-based paint and leave the room free without leaning objects against the walls. In the example room, the work is covered with the 4 L calculated because the measurement was made on the wall surface and a margin was reserved for two coats.
How to paint a room with the PaintUber kit
Doing the entire process separately forces you to calculate the paint and gather the roller, brush, tray, plastic, and tape. The complete paint kit groups those elements so that an individual can receive them in a box and start without an additional visit to the hardware store.
The journey begins by measuring the square meters of wall. For the 20 m² example, the 4 L kit is selected; for about 10 m², the 2 L kit. The reference continues to be 5 m² per liter for two coats and with margin.
Then the color is chosen. If there is doubt, the 100 ml sample is ordered first and tested in the room. Once the decision is made, the corresponding format is selected. All shades on the card cost the same.
Upon opening the box, the kit contains the chosen paint, a 22 cm roller with handle, a flat brush, a tray, a 3.74 x 3.74 m drop cloth, and 45 mm painter's tape. It is the same work order explained in this guide: protect, cut in, apply with a roller, and repeat the coat after the drying interval.
The paint is manufactured by Naturmatt Smart Materials, S.L., and PaintUber, whose parent company is Aleph Zero, S.L.U., sells it to the end customer. The manufacturing plant is ISO 9001 and ISO 14001 certified. After purchase, the guide “How to paint your house in a weekend” is sent by email.
PaintUber does not offer an application service or have a physical store. The approach is aimed at those who live in the house and want to paint it themselves, with all the materials gathered in advance.
Common mistakes when painting a room
Buying paint based on floor area is one of the most common mistakes. A room is not calculated by its usable area, but by the square meters of wall and, if applicable, ceiling.
Another mistake is relying on a single coat because the color looks uniform while it is wet. The assessment must be made after it has dried, and the calculation in this guide already accounts for two coats.
Marks are also caused by pressing too hard on the roller, going over paint that is starting to dry, or leaving the junction between the cut-in area and the rolled area for too long. Keep a short sequence and finish each wall before stopping.
Do not hide active dampness under new paint. If there is a leak, capillary action, or a structural problem, resolve the cause before preparing the surface. Breathable paint allows water vapor to pass through, but it does not fix the source of dampness.
Finally, do not choose a color just because of how it looks on your phone. Testing it on the wall allows you to see how it interacts with the light, floor, and actual furniture in the room.
Frequently asked questions about how to paint a room
How much paint do I need to paint a room?
Add up the square meters of the walls you are going to paint and divide the result by 5. This reference calculates two coats with a margin. For about 10 m² of wall, you need 2 L; for about 20 m², 4 L.
Should you always apply two coats of paint?
This guide and the purchase calculation are designed for two coats. The second coat helps to even out the color and texture, especially when there is a change in tone, repairs, or differences in absorption.
How long should you wait between coats?
Wait between 2 and 4 hours. The paint is dry to the touch in 1 hour, but that information does not replace the recoating interval. Full drying is completed in 24 hours.
Can I paint a wall with dampness?
You should not paint over active dampness without first resolving its cause. A leak, capillary action, or structural flaking cannot be fixed with paint. Identify the source, correct it, and prepare the wall when it is in suitable condition.
Should I paint the ceiling or the walls first?
If you are going to renew both surfaces, start with the ceiling and continue with the walls afterward. This way, you can correct any scuffs or splashes from the initial work on the upper part.
Do I need to buy tools separately?
No, if you choose the complete PaintUber kit. It includes a 22 cm roller with handle, flat brush, tray, drop cloth, and painter's tape, in addition to the paint in the selected color.
The PaintUber room painting kit brings together the mineral paint and the tools in the same box: roller, brush, tray, drop cloth, and tape. Choose the color, enter the wall area, and calculate the size you need to apply two coats. Read next: How to paint a room without experience, step by step.