How to repair water damaged ceiling plaster

Flooding occurs in most apartments/houses regardless of the quality, cost, and freshness of repairs. It is difficult to restore the original appearance of the ceiling and get rid of stains and rust spots, but it is possible. The cause of a flood in a private house can only be a leaky roof. It is with it that you need to start the repair. While it is in poor condition, any effort to restore the interior will not bring anything useful – water at the slightest deterioration of the weather, street dust and dirt, the wind will easily penetrate through the roofing material inside the repaired premises.

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Algorithm of actions to repair water damaged ceiling plaster


Step 1. Fix the cause of the leak

Fix the cause of the leak

It is one thing if the neighbors above forgot to turn off the water in the kitchen and filled three apartments below. This is a one-time unpleasant situation, from which conclusions will be drawn and the leak is unlikely to repeat. Neighbors with an adequate level of consciousness will also pay compensation-voluntarily or in court, depending on the degree of closeness of the relationship.

The second option is worse: in constant mode, the roof leaks every time it rains, or the water pipes in the ceilings are worn out. In any case, you need to solve the problem with water. It is pointless to start repairs until the cause of the leak is eliminated.


Step 2. Prepare inventory and space

Take the furniture out of the room or cover it with a film, remove things, decor, and indoor plants. If you do not reach the ceiling with your hands or reach out uncomfortably, and there is no suitable stable table, prepare a stepladder.


Step 3. Remove the wet trim layers

Remove old plaster with a spatula or metal brush

Remove pieces of wet plaster, putty, and paint with a sharp spatula and metal brushes. Act ruthlessly: do not leave the old and raw layers, even if they still look like they are holding — they will fall off or change the color later when you will not wait. Remove the swollen bumps, paint with streaks and peeling, scrape the surface to clean, and strong material.

There are two possible options for the repair area:

  • Remove the trim layer only on the wet area; grab a 3-5 cm margin from the undamaged part. The method is suitable for small spots and damages; there is a risk of color differences after the final color-even if you paint the entire surface.
  • Remove the ceiling trim over the entire area of the room. Labor-intensive, but get a uniform color and a smooth ceiling.

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Step 4. Dry the room

Dry the room from moisture

The ceiling and ceiling should dry out. Do not spare time — two or three days in dry and hot weather or a week or two with high humidity will save you from new problems with the ceiling. Apply new layers of putty and paint on wet floors — you will not miss new spots.

In severe cases, when natural drying does not help or is obviously useless ( if the weather outside is rainy every day), use a technical hairdryer. This device delivers hot air to the ceiling and walls and speeds up drying. Use a technical hairdryer only for leaks at the junction of floors. It is dangerous to dry a wet ceiling with electrical outlets with a hairdryer. These areas dry themselves. Do not forget to de-energize the room so that it does not short out.


Step 5. Stripping

we clean with sandpaper the ceiling

Clean with sandpaper and smooth the joints. Increase the speed and quality of work if you use a bar for sanding — put a piece of sandpaper or sanding mesh on it, replace it as it wears. For sanding the ceiling with small irregularities, choose a bar on the pullout handle, at the same timeless dust will fall on your head. However, the friction force of such a bar is less than that of a manual one, without which you cannot do with defects greater than average.

Take coarse sandpaper for rough sanding and removing paint from the ceiling.

Cleaning is a dusty stage. We strongly recommend that you wear a headdress, a non-budget respirator, a medical mask from a pharmacy, or at least a gauze bandage.


Step 6. Remove the dust

Walk across the ceiling with a wide soft brush or vacuum cleaner. Along the way, you will want to collect dust on the floor and walls — give in and put an intermediate order. Just do not spread a plentiful wet cleaning; otherwise, you will have to dry the room again.


Step 7. Apply primer and protective equipment

apply a primer to the ceiling

If there are rusty spots on the ceiling after removing the paint and putty, do not expect to hide them under the paint. Get rid of stains with a special tool for removing and protecting against rust. Apply such a tool with a brush, when reacting with materials, the foam will be released and a sharp smell will appear — put on protective glasses and a respirator in advance, and strong rubber gloves. Dry the ceiling thoroughly before the next step.

This is followed by a primer: a special composition will improve the adhesion of the ceiling with putty, get rid of dust residues, strengthen the surface. Choose a primer with additional antiseptic and antifungal properties.

Apply the primer with a wide brush — this way it penetrates better into the surface, in the corners between the ceiling and walls with a narrow brush. Work carefully, splashes and streaks of the primer are undesirable on surfaces untouched by water and on walls, if you did not plan to repair the walls.

If desired and necessary, Prime two layers to improve the quality of the coating. Dry each layer for at least 1-2 hours. Thoroughly wash the roller, brush, and primer cuvette — use them to re-apply the primer before painting.


Step 8. Apply the putty

apply a new putty on the ceiling

We are lucky if there is still putty from the previous repair or remember what brand of putty was applied — even simple white plaster putty from different manufacturers differs in shades. Or choose a putty from scratch-taking into account the type of surface.

Putties for the same type of surface often coexist with each other without problems. But we recommend a test drive: dilute part of the putty and apply it to a 50×50 mm area along the joint of the cleaned and untouched surface. Wait until it dries and assesses whether there are any differences in color, bubbles, or flakes. Then draw conclusions.

Fill in the irregularities with putty, evenly and without haste create an even layer on the ceiling. Make an impression on the next section of the untouched surface 3-5 cm. Wait until the putty dries — on average, this is a day.

If rust spots suddenly appear on the new plaster, do not panic. Take a rust remover and proceed-apply with a brush and remove the stains. You cannot mask it with paint.


Step 9. Finishing alignment

finish the alignment of the ceiling

In low light, pick up a flashlight or install a searchlight – aim the ceiling to see the irregularities. Sand the surface using a sanding mesh or sandpaper. If you find any defects or cavities, apply the putty again, dry it, and align it again.

For rough sanding, use sandpaper with a grain size of 60-80, then go over the surface with emery marked 150-180. Suitable and sanding mesh sheets-for repeated use, sanded with two sides, and more resistant to abrasion than sandpaper.

For problematic ceilings with a large number of initial cracks, we recommend using reinforcing glass wool, the second name-paint spider web. We recommend fiberglass and for those cases when you need increased strength of the ceiling covering-you will get repairs for years.

Reinforce with glass wool individual fragments of the ceiling, where there were many cracks — often in these places, the cracks soon appear again, even when the putty dries. The second option is to stick the glass canvas on the entire ceiling, so you get a uniform strength of the ceiling covering. In both cases, the method is the same: on the last even layer of putty, glass wool is glued using a liquid solution of glue. Cut the desired length of the glass sheet from the roll, apply glue to the glass sheet with a roller, and stick the cloth on the wall. With large canvases, it is easier to work together.

Fiberglass is characterized by a mesh structure, so the finished surface will not be smooth, but with a monotonous texture. Hide the texture of three, not two layers of paint. Alternatively, you can leave a clear texture and even emphasize the non-standard shade of the ceiling.


Step 10. Primer again

Apply the primer again before finishing. Use a roller and brush. The new layer of primer will dry at the same time as the first one — 1-2 hours.


Step 11. Full painting of the ceiling

full painting of the ceiling

Cleared part of the ceiling or the entire area-no difference. Paint the ceiling all over the room, then get the same color. Paint recommend latex paint for the ceiling, for uniform color, apply paint of at least two mutually perpendicular layers. At the same time, direct the final layer away from the window, so that the paint strips do not appear later.

Complete each layer in one step, without interruptions-otherwise there will be color irregularities along the border of the area.

Please note that even the same manufacturer’s paint in two packages differs in color. Buy a little more paint volume than you need — it’s better to let it stay than not enough.

In addition to exclusively water-based paints, acrylic, latex, silicone, or other polymer-based paints are used for ceilings. These paints are resistant to water and humidity and can withstand wet cleaning.

The restoration of the ceiling completed. It was not as bad as it seemed at first glance.