Plastering the ceiling: types of mixtures and leveling technology

One of the most important steps in giving your house or any building a smooth, long-lasting surface is plastering the ceiling. A smooth and visually appealing ceiling can be achieved with the correct plastering technique, whether you’re finishing a new space or remodeling an old one.

Selecting the appropriate plaster mixture is critical to the outcome. Plaster mixtures come in a variety of forms, each with unique qualities and applications. Whether you’re doing minor touch-ups or a complete overhaul of your ceiling, knowing these options will help you choose the best one for your project.

Plastering a ceiling requires a number of steps that must be carefully followed with close attention to detail. A smooth and polished finish is largely dependent on using the proper technique, which includes surface preparation and layering the plaster.

This post will explain the various plaster mixtures that are appropriate for ceiling work and take you through the crucial procedures for properly leveling a ceiling. This tutorial will assist you in understanding the fundamentals of plastering a ceiling, whether you’re a do-it-yourselfer or prefer to hire an expert.

Pros and cons of plaster

Examine the benefits of both options for a specific room before determining which is preferable: stretch ceilings or plaster. If there is a height difference of no more than 50 mm, wet leveling can be used. Heavy plaster finishing pieces can be dangerous to fall from because of the high specific gravity of the plaster mixture. Consequently, use dry leveling if there is a significant disparity in the height of the ceiling surface.

If there are only minor construction flaws, the surface is nearly smooth, there are few small cracks and crevices, and the ceiling surface is putty, with a 3–4 mm layer applied. Plastering is the method used for leveling in intermediate situations.

Benefits of plastering:

• strength,
• monolithic coating,
• environmental friendliness,
• ability to wash;
• no frame required,
• long-term operation,
• repairability,
• do-it-yourself is cheaper than a suspended ceiling,
• reduction in room height is insignificant.

• limited coating thickness;
• requires some work skills;
• can be expensive if you involve plastering specialists.

Plaster was selected as the preferred option when it came to suspended ceilings. Let’s think about the next query.

What is the right way to plaster ceilings, choosing a mixture

When plastering a ceiling, it’s crucial to select the right plaster composition.

The primary requirement that needs to be met is:

• strong adhesion of the coating to the ceiling surface;
• the solution should not create difficulties during application (be excessively sticky or fall off the base);
• the qualities of the mixture must be maintained until hardening begins (stratification, setting before the guaranteed service life is unacceptable).

Additionally, you must decide between creating your own composition and using a ready-made mixture. The components of ready-made mixtures, which typically come in powder form for minerals, are carefully chosen to include all necessary additives, fillers, and binders. Your own compositions are far less expensive. These are more difficult, but if you adhere to the fundamentals, these compositions are just as good as ones that you buy.

You can tell what kind of SS (dry mixture) the seller is selling by looking at the size of the fractions; putty (fraction size less than 0.3 mm) or plaster (up to 2.5 mm).

The environment of the room to be plastered must be considered when selecting the mixture. For damp rooms, simple gypsum compositions are inappropriate. A country house where people live only during the summertime is a better place to choose facade compositions.

Cement-based

These mixes are inexpensive, incredibly potent, adaptable, water-resistant, and long-lasting. Universal and resistant to frost. These are the advantages. The drawbacks include the inability to withstand vibration loads, the lengthy strength-gain period, and the easy-to-crack hardening solution in the event that the preparation and hardening procedures are not followed.

Portland cement is the most common kind of cement used as a binder. There are other varieties as well. To make the cement mortar more malleable, lime is frequently added. Additionally, cement-polymer mixtures exist. White Portland cement is a binder that can be used in decorative compositions.

The solution has a greater specific weight than the mixture of gypsum. The applied layer’s maximum thickness is less than what gypsum is permitted to have. It is a good fit for a concrete base.

Gypsum-based

Plasterers probably have a preference for this type. Gypsum hardens quickly and becomes stronger. The light weight, plasticity, naturalness, adaptability (fitting for most base materials), lack of shrinkage, good vapor permeability, low heat conductivity, and repairability of gypsum plaster are among its benefits.

The primary drawbacks are the rapid setting, low resistance to frost, and fear of water. It complements lime well as a binder. Mixtures of gypsum polymers are also available.

Clay-based

The material is natural and inexpensive—you can practically pick it up with your feet. tried and true over time. Waste-free because dried clay is readily soaked and used again. generates a cozy microclimate in the space. ideal option for sealing a wooden ceiling. utterly safe. You can even apply clay plaster by hand. Warm walls are created when sawdust or straw is added.

Cons: The room has a high humidity level because it dries out quickly; a minimum layer of 10 mm is allowed; it becomes wet from prolonged exposure to moisture.

Modern compositions

Despite their high cost, polymer solutions are robust, elastic, and long-lasting. They adhere more firmly. Adhere to nearly every kind of base. Simple to lay, rapidly build strength, and unafraid of building shrinkage and vibrations. Not scared of damp, not easily harmed by harsh materials.

Among them are:

• acrylic,
• silicone,
• siloxane,
• polymer cement compositions.

They are only appropriate for flat surfaces because they are typically applied in a layer as thick as 3 mm.

Selecting the appropriate mixture and spreading it uniformly are key to plastering a ceiling and producing a level, smooth surface. Depending on the particular plaster mix used and the state of the ceiling, this procedure may change. Achieving a professional finish requires an understanding of the various types of mixtures, from conventional gypsum-based options to contemporary ready-mix solutions. Anyone can learn how to properly level and plaster a ceiling with the right tools and technique, making it a necessary skill for home improvement projects.

Tools and materials

Devices, scaffolding, and tools are required:

• construction trowel;
• a set of spatulas, preferably with rubberized handles (steel, rubber, plastic of different sizes);
• a rule or a rail with a level;
• a trowel;
• a float;
• a paint brush;
• a cord;
• a mixer or a mortar mixer;
• a roller;
• a square or rectangular container for the solution (large volume 15-20 l);
• a sickle;
• sandpaper;
• gloves, a mask or glasses, possibly a respirator, overalls.

Let’s move on to the next query, which is equally crucial for a novice.

How to remove plaster from the ceiling

We will quickly observe that there is no need to remove the old plaster if it still holds strong and has not lost its strength.

Eliminate the worn coating entirely or in sections if it

• is crumbling;
• is completely covered with cracks;
• "blooming" (covered with mold);
• does not hold well (can be detected by tapping on the dull sound) and may fall off.

It is necessary to remove the surrounding areas at a distance of approximately half a meter from the problematic areas in addition to the problem areas themselves when partially removing the old finish.

They de-energize the space by moving the furniture and covering the floors with film or other materials. After that, use a hammer to tap the entire area. As a result, some of the previous coating will come off. Next, complete the task in accordance with the prearranged plan.

Standard manual

Make use of a hammer, hatchet, or spatula. With a spatula, pry up the coating’s edge and use it as a lever to chip off a piece of plaster. In order to push the spatula deeper beneath the old coating, occasionally tap the tool’s handle with a hammer.

Using a brush, cloth, or roller, remove the plaster finish after wetting it with warm water. After allowing it to soak for a while, use a spatula or scraper to remove it.

It is not possible to tap finishing applied over drywall. Select a spot off to the side and mark the finishing area precisely, all the way down to the drywall. Next, use the scraper in the same manner as you would a spatula, being careful not to puncture the cardboard.

Additionally, they employ a "clever method" to remove the plaster "casing" by using a softening compound in place of soaking. This is how it’s ready: One liter of water is mixed with two tablespoons of starch. Using a brush, the product is applied to the plaster coating. A spatula is used to remove the plaster after fifteen minutes. The product is repurposed if the entire layer is not eliminated.

Using a chisel and hammer, the firmly attached coating is scraped off.

Mechanical approach

How can old plaster that is securely affixed to the floor slab be removed? You can use a drill with a chiselling attachment in place of the hammer drill that is used to remove it. Another tool used is a grinder (grind down to the base).

Cut the plaster layer into squares with a grinder, and then use a chisel and hammer in order to chip it off. It’s a dusty and demanding job. It is necessary to have protective gear and a sturdy support.

Plaster removal from ceilings is a challenging task that requires you to work in an awkward position. Thus, it is preferable to leave the old coating in place if at all possible.

How to plaster the ceiling correctly

Plastering has to be done correctly to avoid cracks, stains from different sources, and peeling areas on the plastered surface.

• prepare the surface to be plastered,
• select the composition and mix the solution,
• plaster,
• dry.

The type of composition, base material, and degree of curvature of the ceiling surface are taken into consideration when choosing the plaster layer’s thickness.

Thus, for different mixtures, the minimum and maximum layer thickness is:

• for cement mixture – 10-50 mm;
• for gypsum – 15-25 mm;
• for gypsum-sand mortar – 10-25 (with reinforcing mesh up to 35 mm);
• for clay-sand – 10-35 mm;
• for clay-cement-sand – 15-35 mm;
• for decorative mortar – 10 (less is not recommended, so that it lasts longer).

Based on the foundational material:

• smooth concrete – 2 mm (with differences – 20 mm, greater thickness is made only with reinforcement);
• brick – 5 mm (for leveling – 20-25, with reinforcement up to 50 mm);
• aerated concrete – 2 mm (uneven – 8-15 mm);
• insulation using serpyanka – two layers in the amount of 25-35 mm (under serpyanka 15 mm, on top 10-20 mm);
• wood (two layers), top layer – 15-20 mm;
• drywall – 1.5-10 mm.

Plastering is done without beacons if the thickness of the plaster layer is less than 6 mm. The plaster layer is rubbed and sanded if you intend to apply wallpaper to the ceiling after plastering.

Surface preparation

Removed are old paint jobs, wallpaper, fasteners, nails, and other metal components. Whitewash and the previous plaster coating must also be removed. The dust is removed from the surface.

A novice must understand how to fix seams, ceiling cracks, and other flaws. A wire brush is used to clean the sand and dust, and cracks and seams are widened. Use a brush to apply a deep penetration primer after any dirt has been removed. Apply a layer of cement mortar into which the reinforcing mesh is embedded after a 24-hour period. Using a notched trowel, apply the solution to the mesh once more. After it has completely dried, apply a second layer.

Wet a sponge to remove mold, rust, and fungal traces. After that, apply specialized compounds. mortar and cement

Primer

Prior to plastering, prime the ceiling using compounds that are appropriate for the base materials and the mortar. For instance, to improve adhesion, a concrete contact primer is applied to a smooth concrete ceiling. Use a deep penetration agent to prime porous materials that have the potential to absorb water from the plaster mixture. Apply the mixture in two passes using a roller. Every layer is given a full day to dry.

Preparation of the plaster mixture

Before plastering, the composition is immediately ready. Before beginning work, ready mixes are mixed. If necessary, water is added, but not more than what is specified on the package. A container is filled with dry mixes and water (the manufacturer specifies the volume). Using a mixer, mix the ingredients until a homogenous mass is achieved.

After 20 minutes of standing, cover the solution and stir once more. The mixture is poured into a designated compartment for automated ceiling plastering. The mixture is automatically made.

Installing beacons

Beacons’ installation lines are applied and the ceiling is hung to verify the plane’s accuracy prior to installation. The thickness of the plaster coating (approximately taken for the beginning) determines how far apart the heads of the nails are from the surface when they are driven into the corners.

A taut wire cord is dragged along the heads to ensure that any bulges are present. Any bulges should be cut off. If this isn’t feasible, remove the nails to the bulge’s height plus the minimum amount of plaster that can be applied.

To begin forming the horizontal plane of the future ceiling surface, a nail is driven into the bulge, followed by a nail driven in with a rule and level on the line for beacons. Once the first nail has been positioned on the beacon line, drive in the second nail along the same line, being careful to align the heads of the two nails horizontally.

Once the necessary number of nails have been driven in, install the metal, wooden, or plastic beacons or create beacons out of mortar. Use mortar marks to place beacon strips along the marking line. Install a beacon strip beneath the cord that is stretched between the outer nails, sinking it into the marks so that the top of the strip is in the same plane as the stretched cord.

The bar is fastened either by nails or gypsum mortar. The cord is cut off.

Installing a wooden lath or rule on the nail heads is necessary when creating beacons out of mortar. The entire length is covered with mortar according to the rule. Taking a square spatula and holding it perpendicular to the ceiling surface, cut off any mortar that is sticking out from under the lath on both sides. The rule is carefully removed once the mortar has slightly set. There’s still a rectangular mortar beacon on the ceiling.

It is gently tapped in a longitudinal direction to keep the rule from dragging the mortar with it when it is removed.

The beacons are spaced anywhere from one and a half to one meter apart. It is better for novices to place beacons more frequently. Plastering is followed by the removal of beacons (except mortar ones).

Plastering the surface

Plastering a ceiling can be done using a variety of technologies. One can apply the mixture by smearing or throwing it. Using a trowel, the solution is thrown. When plastering without beacons, the mass is spread across the surface using a spatula to apply the composition. After applying the first layer in this manner, it is allowed to dry. The second layer is then put on. The ceiling surface is cleaned once the solution has set. Using a damp sponge, move in circles without applying pressure.

Finishing layer

Not only should the ceiling be level, but it should also be smooth. It is not permitted to have visible pores that show up after painting. A thin (up to 3 mm) layer of cover or finishing mixture is applied to the plastered surface if you are plastering the ceiling by hand in preparation for painting. It has a thinner consistency and is more plastic-like.

Using a trowel or spatula, apply it while angling the tool. When the cover coat has slightly solidified, level it, move the float over it, and take the excess out of the tool. Ceiling grouting is the term for this process. Press the tool lightly on convex areas. Move in a circular manner at first, then move pressure-free in a straight line at the next stage. The ceiling plaster is grouted, dried, and then sanded with sandpaper in preparation for painting.

Step-by-step instructions for plastering the ceiling with illustrations

1. First stage: prepare the room, remove the layer of old plaster, clean the surface, repair

• Remove the furniture from the room, cover the floor with film.
• De-energize the room.
• Remove the old finish (wallpaper, paint, whitewash).
• Remove metal objects (screws, nails). Isolate the remaining ones with oil paint so that they do not rust as a result of contact with the solution.
• Wash off mold, efflorescence, and rust with a wet sponge.
• We treat stains with special means.
• If there is an old plaster coating, remove it, remembering to put on glasses, a respirator to protect your eyes and respiratory organs. You can remove the coating in several ways (see. above).
• Clean the surface from dust.
• Repair cracks, seal seams and holes in the floor slabs with cement mortar. Expand wide seams and cracks, clean from dust, prime with a brush, fill with foam or rags with mortar. Plaster with mortar with a reinforcing mesh (serpyanka is not suitable).
• Dry, wait for the cement mortar to dry.

The strength of the plaster coating and the overall appearance of the room (including the appearance of cracks and surface stains) are determined by the quality of the preparatory work.

1. Second stage: before plastering the ceiling, prime the surface

• Prepare the primer according to the manufacturer"s instructions.
• After applying primer to a roller, transfer it to the surface to be primed, distributing it evenly with straight-line movements in one direction, leaving no gaps. Where it is difficult to process with a roller, use a brush. Wait for the applied primer to dry completely.
• Apply a second layer, moving the roller in a direction perpendicular to the previous application. Give the primer time to dry.

Priming the surface fortifies the base itself and improves the plaster finish’s adherence strength to the ceiling. impacts the finish’s durability, solidity, and length of trouble-free operation.

1. Stage three: install beacons

The smoothness of the ceiling surface and the room’s overall appearance are decided by this operation. It also establishes how much plastering material is used.

• In order to evenly plaster the ceiling part of the room, we determine the “plane of the ceiling horizon”, create reference points for the surface of the coating – beacons (cm. higher). We purchase metal or wooden profiles.
• We fasten the laser level meter to the wall at the lowest ceiling angle. On it we will orient the top of the lighthouse planks.
• Using a roulette and a plane shredded by a laser, we find the lowest point of ceiling overlap. You can also determine this point using the cord. We mark the point with a pencil. It will be determining for the placement of lighthouses in height. The minimum height of the lighthouse profile is 3 mm, the thickness of the coating in the amount of – 6 mm. So the top of the strips should be below the point by 6 mm.
• We apply a pencil to the surface of the light mount line. We select the distance between them so that it does not exceed the length of the rule minus 20 cm.
• To fix the bar along the line, we make a brand – Putings of a solution of gypsum. We apply the profile to the stamps, scattering it so that the top definitely coincides with the "plane of the horizon". Remove excess mortar protruding above the profile with a spatula. We give the solution time to get stronger by installing the beacon on the next line.
• If the thickness of the future coating exceeds 2 cm, install a reinforcing mesh.

1. Stage four: preparing the SS mortar for plastering

• Pour water into a square container intended for the solution in an amount slightly less than indicated on the package.
• Add all the mixture that is in the package.
• Having immersed the end of the mixing attachment in the mixture, turn on the mixer. Mix the contents of the container until the mass becomes homogeneous. If the dough turns out thick, dilute with water to the desired consistency. At the same stage we add color if a colored solution is needed.
• Cover the mixed solution with film or a lid. Let it sit for 20 minutes. Then mix again.

1. Stage five: plastering the surface.

• Start applying the plaster mortar between the two beacons (the first and second from the edge, not between the corner and the first beacon). Fill with mortar
• As professionals recommend to beginners, when applying plaster to the ceiling, first apply a thin contact layer and immediately on top of it – the main amount of mortar, which is already coming out over the beacon strip. Using a contact layer reduces the amount of waste (mortar falling off the surface).
• With a rule pressed against the beacons, moving towards yourself, stretch the mortar. We collect the excess mass removed by the rule from it with a spatula and send it to where there is not enough mortar. We pass the rule several times until the entire surface is leveled.
• We continue plastering the ceiling in a similar way along the beacons until we manage to plaster the entire surface. To level the mortar between the outer beacon and the wall, rest the rule on two nearby beacons.
• Wet the sponge with water, moisten the surface of the set solution (we do it with a sponge without pressing).
• We polish the surface with a wide spatula.
• We pry up the beacons with a spatula, remove the planks from the solution.
• We fill the grooves with the solution, leveling it with a wide spatula. We also wet and polish. Plastering on the e is completed.

Putting the solution into the grooves

Is it possible to mechanize plastering of the ceiling

Using mechanization makes plastering ceilings easier. Specialized ready-made mixtures are used for mechanized plastering of walls and ceilings because regular mixtures harden too quickly, are not plastic enough, and stick to tank walls easily, clogging the nozzle. Plastering by machine is completed in one pass. The mixture is applied, and then leveling is done by hand.

How to level a ceiling with plaster

Plastering the ceiling with beacons allows for leveling if the surface is too uneven. Beacons are installed with a laser level meter and a level rule. Beacons are not used during leveling if the surface is nearly flat.

Relatively flat ceilings

Plaster is applied to relatively flat ceilings in two or even three layers. In this instance, the first layer need not be complete; it can be partial (plastering only certain areas). Reinforcement is utilized if the layer thickness exceeds one centimeter. Before plastering, the mesh is tension-fixed to the surface. It ought to be encased in plaster.

Ceilings with large irregularities

Use beacons to plaster the ceiling if there are significant irregularities on the surface (greater than 2 cm). Using a medium-width tool, apply the composition with a spatula so that the mixture extends above the beacons. Level the applied mixture by moving the rule in a zigzag pattern. The surplus is taken out of the rule and applied to the areas that require restocking. One shifts the rule to apply to oneself.

Some features of plastering other ceilings

A solitary response to the query, "How to plaster a ceiling?"It’s not possible. Everywhere has subtle differences.

Wooden ceilings

Preparation is essential when plastering a wooden ceiling. The ceiling is covered with two layers of shingles or a metal mesh attached with 10×10 cm cells. In the absence of this, the plaster layer will split and cling to the wood shakily.

The two applied layers have both dried. Applying the first one causes it to rise just a little bit above the shingles. A spatula is used to level the layers.

How to plaster a plasterboard ceiling with your own hands

The material drywall is a finishing touch. However, following painting or wallpapering, joints and nail heads could show. Using a serpyanka covering for the joints, the plasterboard ceiling is leveled. There is a maximum layer thickness of 15 mm.

Plastering over ceiling insulation

Occasionally, polystyrene foam sheets are affixed to the ceiling surface to act as insulation. The insulation is then plastered over in two stages. The insulation’s surface is primed first. Next, a layer of a more liquid mixture is applied over the dried primer, and painting mesh is placed on top, pressing it slightly into the layer. By overlapping, the mesh panels are connected. The surface is primed once more after the first layer dries, and then a second layer of a thicker solution is applied. As usual, work with this layer.

Using decorative plaster

Not the technique, but the position’s inconvenience makes decorative plaster finishing challenging. The methods are the same as for ornamental wall plastering. Novices should work on the walls for practice. But why not give it a shot with the ceiling if you’ve had success with it before?

Plaster a strip along the wall starting in any corner of the space. Spread the solution on the ceiling right away to stop it from taking off. Utilize the pattern as you see fit. Dry the finish after plastering is finished. The next step of work will be grinding, followed by painting the ceiling (you can also wax it), if the decorative composition is not tinted.

Manufacturers and consumption

Generally speaking, it can be challenging for a novice to determine which plaster is better and what to plaster with. As a result, trusting the counsel of qualified plasterers and the standing established by well-known brands is simpler. Mixtures from Ceresit, Knauf, Volma, Bolars, Starateli, and Plitonit, for instance, are deserving of consideration.

The approximate volume of leveling plaster and putty needed for the ceiling is calculated ahead of time to prevent plastering from being interrupted by a lack of building supplies. A straightforward formula that multiplies the area of your ceiling by the average coating thickness is used to determine the plaster consumption. By adding up the measurements taken at various points along the beacons and dividing the total by the number of measured points, the average thickness value can be found.

A 20% increase (in reserve) is applied to the final number. This is where beginners should start. Positives rise by 5%. By dividing the required mixture volume by 100, you can determine how many standard squares (10 mm layer thickness) there will be. Next, figure out how many packages of the mixture you’ll need to buy to level the ceiling with plaster yourself by referring to the manufacturer’s data. The consumption is marginally lower for ceiling plastering that is done mechanically. You can get assistance with the calculations by using our leveling plaster calculator online.

Errors made in the work

Failure to adhere to ceiling plastering technology is a particularly frequent error. Shrinkage cracks, edema, coating fragments falling off, and reduced strength could be the outcome. If the plaster has come off, it could be the result of improperly sealed cracks and seams or poor adherence.

Breaks or the use of compositions from various batches can result in stains on colored plaster. When drying, a draft or extremely hot weather can cause shrinkage cracks to appear.

Type of Mixture	Leveling Technology
Gypsum Plaster	Apply with a trowel, smooth with a float, and sand after drying
Cement-Based Plaster	Use a trowel to apply, level with a straightedge, and finish with a sponge float
Lime Plaster	Apply with a trowel, use a straightedge for leveling, and polish with a metal float
Ready-Mix Plaster	Spread with a trowel, smooth with a straightedge, and sand after curing

Although plastering a ceiling can appear like a difficult undertaking, anyone who is willing to put in the work can accomplish it with the correct planning and knowledge of the materials. Selecting the ideal choice for your particular project is made easier by being aware of the various kinds of mixtures that are available.

Patience and meticulous attention to detail are essential when leveling. If you use the right methods, you can have a polished, seamless finish that makes your room look better overall.

Gaining an understanding of the fundamentals of ceiling plastering will help you achieve the desired results whether you choose to work with a professional or take on the project independently. Your ceiling can look fantastic and last for a long time with the correct method.

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