- Surface Analysis
- Horizontal break
- Collection of information
- Surface preparation
- Joining seams
- Lighthouse ceiling plaster
- Installation of plaster beacons
- Plastering works
- Ceiling putty
- Preparatory work
- Putty and sanding works
Let’s consider the overhaul of the ceiling step by step: from the analysis of its surface to preparation for painting. We will take as the initial conditions that you have not done anything like this before, but are full of enthusiasm to master this difficult construction process..
Any more or less serious work begins with the collection of information and analysis. First of all, we assess the state of the ceiling at the current moment and outline an action plan in order to bring it to the desired form.
To ensure that the information is accurate, and not taken by eye, it is useful to start off the horizontal.
For this we need a water level (WL) and an assistant. Of course, it would be easier to use a laser level, but not everyone can afford to buy such an expensive tool..
So, remembering the laws of physics that the liquid poured into the tube of our VU will always be in the same plane at its different ends, we make marks with a pencil at all internal and external corners of the room at this level. And in the case of a significant room size, it is useful to leave several beacons on the wall spans. We connect the dots with a paint cord.
Since the quality of the entire ceiling as a whole will depend on the quality of the horizontal that we break off, then your work should be checked. Using the same water level, we compare two absolutely arbitrary points on the horizontal and only then proceed to the subsequent work.
Collection of information
The information we need should include:
- Base type (reinforced concrete slabs, wood, “shingle”, metal structure).
- Base horizontality (base deviation from horizontal).
- Ceiling type (monolithic glued, monolithic painted, suspended plasterboard, stretch, amstrong, plastic, etc.).
As the most common, consider a monolithic ceiling painted with lime-chalk whitewash with a horizontal (up to 3 cm drop) reinforced concrete base. Unfortunately, there is no such thing as perfectly horizontal concrete slabs, this is a myth..
Since, apart from a flat surface, we do not have any special architectural and design requirements for the future ceiling, we accept the following construction plan.
- Surface preparation:
- washing of whitewash;
- jointing of seams;
- Lighthouse plaster:
- installation of beacons;
- plastering work.
- preparatory work;
- puttying and grinding work.
Before building anything, you need to properly prepare the work surface. That is, to remove everything that was built before us. In our case, it is necessary to wash out the lime whitewash, although it could be the dismantling of the plasterboard ceiling with a metal frame and cleaning the surface from paint and varnish coatings, and much more.
To wash the whitewash, we need water, soda ash, a spatula and a spatula.
Dissolve 3-4 tablespoons of soda in 8-10 liters of heated water. With the resulting solution and with the help of a scrubber, we moisten the whitewash. You should not strive to process the entire ceiling sheet at once. This process is long and tedious. We saturate small areas with water, until the whitewash swells. Then we clean the last with a metal spatula.
When the cleaning of the ceiling from the whitewash is finished, you should pay attention to the seams between the reinforced concrete slabs. The mortar very often used for sealing joints cracked and chipped in places or simply fell behind the base. All such fragments should be removed. This is done with a chisel or puncher. We seal the seams cleaned from the old mortar with construction glue, such as Perlfix. Sealing is a mandatory step, despite the fact that the entire surface of the ceiling will subsequently be plastered.
The ceiling prepared for work must be primed, this will strengthen the working base and increase its adhesion. For these purposes, the ST-17 deep penetration ceresite primer is perfect, as well as any other similar purpose. Do not listen to those who will advise you to apply primer from a spray gun, speed will never replace quality. The soil must be saturated and in no case be sprayed.
Lighthouse ceiling plaster
When the ceiling sheet is cleaned of whitewash, all chips are removed, and the primer is dry, you can proceed directly to plastering work.
The choice in favor of the lighthouse plaster was made, starting from the fact that the plane of the ceiling we are considering does not have significant height differences. Two or three centimeters is not a problem, five is unpleasant, but you can work, but with a drop of more than 5 centimeters, you should make a choice in favor of suspended or tension products. For all its high cost and other disadvantages, such ceilings have one indisputable advantage, they easily hide all the differences and irregularities in the floor.
Installation of plaster beacons
Like other construction work, the installation of plaster beacons begins, of course, with analysis and marking. First, let’s decide on the direction. When choosing the direction of the lighthouses, one should take into account the geometry of the room, its dimensions and the dimensions of the lighthouse profiles we have. If possible, during the installation process, they should not be docked, but should be solid along their entire length. That is, if your room is three by four, and the lighthouse is three meters long, then you need to lay them parallel to the short wall.
Using a tape measure and a painter’s thread, we beat off the lines along which the lighthouse profile will be laid. The beacon distance should be ten to fifteen centimeters less than the size of the correct rail we have. For a beginner, and not only, a one and a half meter rule will be optimal, which means that the distance between the marking lines should be 135-140 cm.
When the “drawing” work on the ceiling is completed, take a puncher in our hands and dowel the ceiling in all four corners of the room so that the holes are located 4–5 centimeters from the wall. In the lowest corner of the ceiling (and we can easily determine it by measuring the distance from each corner to the horizontal we beat off), unscrew the dowel to the height of the lighthouse profile plus 4–5 mm. This will be the zero of our ceiling. Using a level and a tape measure, we unscrew the remaining three dowels into one level with zero, while pushing off from the horizontal line we had broken off earlier.
This stage of work also needs to be checked. To do this, take a thread and connect the dowels of opposite corners with it, while the lacing should be fixed as close to the cap as possible. If the threads intersect, that is, they lightly touch one another, the plane is built correctly. If there is space between them, or vice versa, the threads press one against the other, there is no plane. This defect can be easily eliminated with an ordinary screwdriver. Unscrewing or twisting the dowels, we achieve the desired result.
Further, on the dowels set in level in one plane, we fix the lacing parallel to the long wall of the room, that is, perpendicular to our markings. We attach the lacing as close to the head of the nail as possible. It is this lacing that will serve as a guide for installing the lighthouse profile. If the length of the beacons is more than two and a half meters, you should install additional dowels and pull an additional thread.
Now you can start installing the beacons themselves. Finishing plaster putty is great as an adhesive. Adhesive mixtures such as “Perlfix” and “Fugenfüller” harden very quickly, and plaster mixtures do not have the required viscosity.
We install the lighthouses one by one, one by one. First, along the marking line, we make gypsum “bloopers” every 15 centimeters, then we put the beacon under the lacing and glue it so that it does not touch the threads for a fraction of a millimeter. We check the correctness of the installation of the lighthouse with a long, 2-2.5 meter level or rule.
In the same way, we install all subsequent beacon profiles. In this case, you should pay attention to the fact that neither the lighthouse nor the glue mixture touches the stretched lacing, as this can interfere with the correct construction of the plane.
After the beacons dry, we dismantle the dowels and threads.
Now you need to decide on the choice of plaster mix. You can, of course, use a traditional lime-cement mortar, but if possible, it is better to give preference to gypsum plaster mixes like Rotbant. This is explained primarily by the method of applying solutions. The gypsum mixture can be simply spread on the ceiling with a spatula, while the lime-cement mixture must be thrown onto the surface, which in the case of ceiling work is extremely inconvenient.
Before “hammering” the selected mixture, you need to once again inspect our lighthouses. Walk along them with a rail, make sure that it slides along the profiles easily, without snags, that the putty used for installation does not protrude anywhere on top of the beacons and does not interfere with the movement of the rule.
And only after that we pull the lighthouse plaster. This process is physically time consuming, but does not require significant mental effort. You just need to monitor the consistency of the solution..
It should be moist enough to stick, but not too liquid to apply a layer of 2-3 cm. It is not recommended to do thicker layers in one throw. It is better to plaster such problem areas in two stages, that is, to make a rough skim, wait for it to dry and pull it off clean. In general, if the lighthouses are set correctly, there should be no problems with plastering work..
Like any other construction process, plastering the ceiling on the lighthouse plaster requires certain preparatory work. These, for example, include: removing the lighthouses from the ceiling sheet, sealing the formed depressions, primary grinding, and priming the surface. But let’s go in order.
If the ceiling is being prepared for painting, the lighthouse profiles should be removed from the ceiling sheet. This is done in order to avoid the formation of cracks along the line of the profile remaining in the plaster. The resulting grooves are sealed with the same “Rotbant” that was used in plastering works. After drying on the plastered surface, you need to “walk” with a grinding mesh of the eightieth number. We do not pay any attention to depressions and sinks, our goal is to remove irregularities and roughness. Such preparation will facilitate the subsequent puttying process and make it of better quality..
After any sanding, the surface must be primed. To do this, we take the already familiar ceresite primer ST-17.
Important: any sanding process is followed by a priming process, but not vice versa. The primed surface resembles stone in strength, and is very difficult to process.
Putty and sanding works
Puttying is just that construction process when it is better to see once than hear a hundred times, and even more so read two hundred times. Everything is important here, any little things. Starting from the thickness of the putty mixture and ending with the movement of the putty knife, and if you have never seen how the master putsty, it will be quite difficult for you to understand this not the simplest construction process.
So the advice will be given on the assumption that you have an approximate idea of the process itself, but do not know all its nuances. After all, even if you have repeatedly observed the work of the master, you simply could not pay attention to many points:
- You need to pay attention to the thickness of the solution. The mixture should resemble oil and easily stretch over the work surface with a thickness of about one millimeter.
- The container for preparing the mixture, like the working tool, must be perfectly clean. Not even a piece of already dried putty, or any other, even the smallest debris, should get into the solution, even by accident. Perfectly clean mixture is a guarantee of high-quality work without unnecessary labor costs.
- Do not try to stretch the putty onto free, not yet putty areas, on the contrary, pull the putty from such places onto the already treated surface.
- Apply pressure to the spatula. The main pressure falls on the part of the tool that moves along the area clean from the putty. The other side, as it were, glides freely over the surface, without scratching the previously completed work.
- From time to time, clean the dry mixture with a spatula. In no case do not throw these residues into a container with a putty – this is already a waste material, which in its density will differ from the rest of the homogeneous mass, which means it will interfere with the quality of the work.
- You should not strive to do the job perfectly in the first layer. Don’t waste your time and energy, it is unrealistic even for an experienced professional. There will be another layer of putty, there will be sanding, it is these construction processes that will bring your ceiling to the ideal.
- After applying the first layer of putty to the entire canvas, apply the second one immediately. If for some reason this is not possible and the putty is dry, you will have to wait for it to dry completely, then grind, prime the ceiling and only then putty with a second layer. So calculate your strength, and try to complete the putty in one day..
- For final sanding, it is better to use sandpaper than a sanding mesh. And let the latter work much more conveniently, but small brands of sandpaper (240, 320) do not leave any scratches on the treated surface.
- This is just the final primer, especially if an acrylic putty was used, it is best to apply it with a spray gun or with a compressor. This will save you from the stains put on by the baker and prepare the ceiling for any type of painting..
In the end, it should be noted – if you are not confident in your abilities, it is better to entrust the construction work to professionals, this can save you from many disappointments.