What thickness of plasterboard to use on a Knauf ceiling. Thickness of plasterboard for the ceiling - what size of ceiling plasterboard to choose? Requirements for gypsum boards for ceiling placement

Drywall is one of the solid sheet materials used to form an additional coating on top of the rough base for subsequent finishing. Gypsum is hygroscopic and afraid of water, so gypsum board can only be used for interior decoration of building structures; installation of plasterboard on the ceiling is one of the areas of its application.

Let's consider which drywall is preferable for ceiling finishing.

Requirements for gypsum boards for ceiling placement

The ceiling is a specifically located base, so additional requirements are imposed on the materials for its finishing. Drywall today is produced in several types, differing in characteristics and, accordingly, scope and methods of application. To choose plasterboard for ceiling finishing correctly, you need to know the selection criteria, which, in turn, are based on the following requirements for covering a gypsum plasterboard ceiling:

1. Acceptable specific gravity - any suspended structure is affected by gravity and the lighter the structure, the less likely it is to be torn off from the base;
2. Rational functionality - the degree of resistance of the material to certain factors must correspond to operating conditions, and its reserve must be in demand;
3. Possibility of arranging joints of sheets with the required quality - the requirements for joining seams for finishing with painting and wallpapering differ.

Based on the listed requirements for the material, we will consider the appropriate selection criteria and which type of plasterboard to give preference to for installation on the ceiling.

Choosing gypsum boards for the ceiling

In relation to some types of plasterboard, you can hear the definition “ceiling”, but it is used only in everyday life - gypsum plaster boards with this name or marking are not produced, just as ceiling chipboards, fiberboards or plywood are not produced. The characteristic “ceiling” is conditional and implies a smaller thickness of the sheets, which means their lower weight.

Ceiling plasterboard thickness

GKL is available in the following thicknesses (mm): 6.5; 8.0; 9.5; 12.5; 14.0; 15.0; 16.0; 18.0; 20.0; 24.0. For domestic use, plasterboard manufacturers offer three of the listed types - 6.5, 9.5 and 12.5 mm thick, the most common in the retail chain. GKL with a thickness of 9.5 mm is commonly known as ceiling, the weight of 1 m2 of such material is approximately 7.5 kg - this value differs slightly for ordinary, moisture-resistant and fire-resistant materials.

Sheets with a thickness of 6.5 mm are called arched, although they are most often used on the ceiling - for cladding structures of complex shapes.

Recommendations for the use of gypsum board sheets 6 or 9.5 mm thick on the ceiling, according to the definition of “ceiling”, are not categorical and universal. A single-level covering can also be mounted from 12.5 mm thick plasterboard - many even prefer this size to a thinner material, as it gives the structure some additional strength. Taking into account the increase in the weight of 1 m2 of sheet by at least 2 kg, the pitch of the load-bearing CD profiles of the frame for laying gypsum boards should be done not at 60, but at 40 cm - with a standard plasterboard width of 120 cm, such an arrangement is not difficult.

If the suspended ceiling is arranged multi-level, the load on the metal structures of the covering closest to the load-bearing base increases, so finishing this tier with sheets 9.5 mm thick is not always justified - if the frame is insufficiently rigid, cracks may appear at the gypsum board joints. In such cases proceed as follows:

1. To finish the horizontal sections of the first level of the ceiling, plasterboard with a thickness of 12.5 mm is purchased;
2. For horizontal lines of the second and third tiers, gypsum boards of 9.5 and 6.5 mm are selected;
3. Vertical surfaces of all levels are faced with arched (6.5 mm) plasterboard.

When choosing the thickness of gypsum plasterboard for multi-tiered coverings, you should also take into account the nuances of the finishing of the suspended ceiling. If you plan to use decorative overlays to decorate the surface, then their weight should be taken into account. It is better to place wood products on 12.5 mm thick plasterboard - on the first tier of the ceiling. Elements made of polystyrene foam can be placed at any level of the coating - their weight is low.

It is better to form areas of suspended finishing of oval shapes, with complex decorative interfaces of planes and without overhead decorations from gypsum plasterboard with a thickness of 6.5 mm - thicker drywall is more difficult to bend, and it is also heavier.

Degree of moisture resistance of gypsum boards for ceilings

Sheets in a green cardboard shell with blue markings are moisture-resistant plasterboard (GKLV), which can be used in rooms with air humidity up to 80%.

In dry rooms, ordinary sheets can also be mounted on the ceiling - in a gray shell, but even in such places the occasional presence of steam cannot be ruled out, for example, from the neighboring kitchen, or a pinpoint leak of water from the apartment above. A gypsum board coating will cope with these factors, but for ordinary drywall, even short-term such effects will not pass without leaving a trace - the material will absorb moisture and become deformed. Conclusion: even in dry rooms, it is better to install moisture-resistant plasterboard (GKLV) on the ceiling - the difference in the price of the material for this potential is completely justified.

Ceiling coverings made of gypsum board with a thickness of 12.5 mm, with significant leaks, retain their geometry longer than moisture-resistant material of 9.5 mm.

Fireproof plasterboard for the ceiling

This material is produced in thicknesses of 12.5 and 15 mm in a pink cardboard shell. The gypsum component of gypsum board contains inclusions of fire-resistant clay and crystallized water (1% of the total mass), is impregnated with fire retardants, and the middle layer of the sheet is reinforced with fiberglass - all this allows fire-resistant plasterboard to withstand open fire for an hour, unlike conventional gypsum board, which in such conditions will collapse in 20-25 minutes. The specific gravity of gypsum board is 850 kg/m3, which is 50 kg more than that of conventional drywall - this should be taken into account when installing the frame.

Fire-resistant plasterboard is used as passive protection against fires - for finishing communication shafts and chimneys, creating partitions with internal arrangement of electrical cables, and equipping rooms with strict fire safety requirements.

GKLO is twice as expensive as regular drywall, so its use in an apartment must be justified. In the absence of structures that are subject to strong heating or require fire-retardant finishing, the use of fire-resistant plasterboard in housing is inappropriate - its fire resistance will remain unclaimed, and it does not have an advantage in strength over other types of gypsum plasterboard.

The same can be said about GKLVO (moisture- and fire-resistant plasterboard) - if there is no need for such a material, the costs of purchasing it for home decoration will be unjustified, but there is no prohibition on its use.

GKL edge profile for ceiling finishing

Depending on the method of arranging the seams, plasterboard is produced with a working edge of the following 5 types:

1. Straight (PC) – without filling joints;
2. Semicircular from the front side (PLC) – with putty without reinforcement;
3. Rounded (ZK) – with filling of joints without reinforcement;
4. Semicircular thinned (PLUK) - filling joints with subsequent reinforcement and puttying;
5. Refined (UK) - with reinforcement and subsequent putty.

The material is selected with an edge corresponding to the type of finishing. Considering that plasterboard coverings, especially ceilings, are susceptible to cracking, the seams of sheets for painting or wallpaper should be firmly sealed and finished smoothly.

Therefore, it is necessary to use gypsum boards with PLUK or UK edges - they are designed to seal sheet joints with reinforcement with mesh tape, which will be recessed locally into the structural groove and then hidden flush with the surface with putty.

Conclusion

Knowing the criteria for choosing plasterboard for finishing the ceiling turns the purchase of this material into a simple procedure, but you should also remember other requirements for gypsum boards, for example, the integrity of the sheets, the absence of fixed deformations of the products, as well as dents, dirt and traces of wetting on their surface - evidence of improper storage of the material , fraught with problems when performing finishing.

The idea of ​​selecting drywall for finishing a particular structure will be more complete after watching this video:

Calculate the cost of installing drywall on the ceiling!
Make a list of works and get a cost estimate in 10 minutes from crews and craftsmen!

The building materials market offers a wide selection of drywall. As a rule, the price depends on the properties of the material, so in order not to overpay, you need to understand the features of each type of drywall. We will tell you what kind of drywall there is, and decide for yourself what is best for you.

Ordinary plasterboard sheet (GKL)

This is the most common type. The popularity of gypsum board is explained by its versatility; it is suitable for installation in any room: office, residential, industrial, with standard humidity levels.

Info! Externally, gypsum boards are a gray sheet with blue markings.

Fireproof plasterboard sheet (GKLO)

Fireproof plasterboard has increased resistance to open flames. This is achieved by adding reinforcing substances to the sheet core. GKLO is rarely used for finishing residential premises. Its use is more appropriate for the renovation of premises with increased fire safety requirements. For example, warehouse and industrial premises, ventilation, attics, power supply panels, transformer substations, securities storage facilities.

Info! The marking color for fire-resistant plasterboard is red.

Moisture-resistant plasterboard sheet (GKLV)

Antifungal substances and silicone granules are added to the composition of GKLV gypsum. This makes drywall sheets less sensitive to high humidity. The basis for GKLV is impregnated cardboard. To achieve the maximum effect of moisture resistance, it is customary to cover the front side of such drywall with a finishing material that has moisture-resistant properties. It can be waterproof or varnish.

Most often, gypsum plasterboard is used in the renovation of bathrooms, toilets, garages, and car washes. Although, if you have a high probability of being flooded by your upstairs neighbors, you can install moisture-resistant cardboard in any other room.

Info! GKLV sheet is green with blue markings.

GKLVO

Moisture-resistant, fire-resistant plasterboard sheet is a combination of the key properties of GKLV and GKLO. The most advanced type of drywall is, naturally, the most expensive. In production facilities with strict safety requirements and operating conditions, only GKLVO is used. Like gypsum plasterboard, it tolerates high levels of humidity.

Info! It is usually green in color, with red markings.

Types of edges of plasterboard sheets

An important parameter when finishing a surface with plasterboard is the shape of the edge of the sheet.

There are the following options:

Straight edge (SC) - used for “dry installation”. If the drywall layer is not the top one and the joints will not be treated with putty, then PC is suitable.

Thinned edge (ED) - after installing drywall, it is assumed that reinforcing tape will be used and subsequent treatment with putty.

Rounded edge (ZE) - similar to ED, but without the use of reinforcing tape.

Semicircular edge on the front side (PLC) - similar to SK, but has a rounding on only one side; it can also be puttied without tape.

Semicircular thinned edge (PLUK) - the joints between such sheets should be treated with both tape and putty.

How to choose drywall thickness

The standard thickness of plasterboard for the ceiling is 9.5 mm, but experts advise taking a denser option - 12.5 mm. The heavier the sheet, the more difficult it is to work with, but 12.5 mm plasterboard is more reliable in operation.

Types of profiles for drywall

Once you have decided on the sheets and their subtypes, it is worth figuring out how to choose a profile for drywall.

There are two main types of ceiling profiles: CD and UD (the marking of ceiling profiles ends with the letter D).

UD profile

Parameters for UD: width - 25 mm, thickness - 25 mm, length from 30 to 40 cm. The thickness of the metal depends on the manufacturer, on average it varies from 0.4 to 0.5 mm. The middle plate of this profile is profiled, so it is stronger and stiffer than the side ones.

The UD profile performs an auxiliary function; it is used as a CD mount.

CD profile

Almost the entire load from drywall falls on the shoulders of the CD. Each sheet is attached to at least four such profiles.

CD parameters: width - 60 mm, height - 25 mm, length - from 30 to 40 cm. The metal thickness is the same as that of the UD profile, from 0.4 to 0.5 mm. The CD is fully profiled, which gives additional rigidity.

Today, no one can specifically answer the question of what kind of plasterboard should be used for ceilings. In order to choose the right type and understand what the thickness of plasterboard for the ceiling should be, you need to take into account many factors that are of great importance during repairs.

Types of ceiling plasterboard

There are three main types of gypsum boards: ordinary sheet, as well as moisture-resistant and fire-resistant. Let's look at each of them:

1. Ordinary plasterboard sheet. Most often, the cladding is made with an ordinary gypsum board sheet, since it meets all the required parameters and is almost universal. It is used not only in everyday life, but also in office premises. This variety has its own characteristics, such as: gray color and blue markings. The thickness of the sheet depends mainly on the manufacturer itself. The average size is from 8 to 9.5 mm. But most often, a material equal to 12.5 mm is used for ceiling cladding. This thickness has its advantages. First, thin ceiling plasterboard is easy to install. Secondly, due to the light weight, the overall structure will have less weight. This type is made from environmentally friendly materials, so it does not contain substances harmful to the human body. Since this is the most common type, it is accordingly very accessible and inexpensive. But despite its simplicity, it is very practical. With an ordinary gypsum board sheet, you can easily mount various lighting items, such as light bulbs, LEDs, chandeliers, and build multi-level structures, since the size of the sheet allows this.
2. Fire resistant. The main feature of such materials can be understood by the name. These are sheets with a high level of durability and resistance to high temperatures. All this is thanks to the chemicals that are added to the composition. As a rule, it is used in places where there is a high level of fire safety: ventilation shafts, production facilities, archive rooms, storage facilities and many others. This kind of hanging cardboard is gray in color with red markings; you can also find pink plasterboard sheets. You can choose a fire-resistant type, such as what type of plasterboard is needed for the ceiling, depending on the weight of the structure. Since the sheets have different weight and thickness parameters, it will not be difficult to choose what you need. By installing fire-resistant sheets in your country house, home, business or office, you can increase the level of safety of the premises. They do not allow the fire to quickly spread throughout the room, and even if there is a fire, the epicenter of the flame can be quickly extinguished.
3. Moisture-resistant ceiling sheet. This material contains chemicals that resist the appearance of fungus, as well as silicone, which is resistant to high levels of moisture. The layer of moisture-resistant gypsum boards is on average 12.5 cm. Typically, moisture-resistant material is used in rooms such as the kitchen, bathroom, toilet, because it is in these places that there is a high level of moisture. Like other types, moisture-resistant has its own colors. In this case, it is light green with blue markings.

Having figured out what kind of plasterboard for the ceiling you need, one cannot help but highlight another important point. In addition to the main features, this material is also distinguished by the type of edge.

Types of material by edge type

There are several different types of edge:

• straight edge is used in dry installation. It is used in multi-layer ceiling structures as an inner layer;
• the thinned edge after installation is provided by gluing with reinforced tape or puttying;
• the rounded edge is used when sealing joints with putty without the use of reinforced tape;
• semicircular and refined edge. After its installation, the use of both putty and reinforced tape is required.

Most often, a thin edge and a semicircular edge are used, since, thanks to such materials for plasterboard coverings, it is possible to seal the joints as evenly and accurately as possible, almost perfectly.

Before installing plasterboard sheets, you need to carefully prepare the room. After the gypsum board for the surface of the required thickness has been attached to the metal profiles, seal all joints and screws using ordinary putty.

On a note: But before installation, thoroughly clean the surface from various irregularities, roughness and other defects that may interfere with installation.

You can level the walls and ceiling using regular sandpaper. Next, treat the surface with a primer using a construction roller. After the primer has dried, you can safely putty.

So, all types of gypsum boards, their characteristics and features were considered. It was also described which of them are used most often in repairs. The builder can only choose which drywall to use. These descriptions and tips will help you make a high-quality ceiling installation.

Video on the topic

Leveling the ceiling with plasterboard allows you to improve the fire protection and sound insulation properties of this structure, hide deviations in level and electrical wiring, and obtain surfaces suitable for decorative finishing in the shortest possible time. This technology is considered relatively simple, the emphasis is on choosing gypsum boards with the right characteristics (with the required edge, thickness, moisture or fire resistance), carrying out accurate markings, creating a reliable frame and processing the joints of the sheets after finishing the sheathing. To eliminate errors, be sure to draw up a diagram of the location of guide profiles, plates and holes for lighting.

In this case, there is no specialized variety; the term “ceiling” refers to ordinary drywall with a thickness of 9.5 mm. It is used in rooms with normal humidity (up to 70%), directing the front side into the room. In kitchens, bathrooms and toilets, an option with core and cardboard impregnated with hydrophobic substances is selected. This treatment allows them to withstand constant exposure to steam and moisture (even washing), they do not deform or become covered with fungus.

If there are increased fire safety requirements, the surface is sheathed with fire-resistant boards that can withstand up to 6-7 hours of direct exposure. This type is used in residential apartment buildings and private buildings to slow down the spread of flames; for the same purpose, they are chosen for finishing archives, utility and industrial premises, storage facilities, and ventilation systems. If it is necessary to combine the properties of moisture and fire resistance, GKLVO sheets are purchased; such a need most often arises when arranging industrial facilities. All specialized brands are represented by plasterboard of medium thickness - from 9.5 to 12.5 mm; a smaller range is selected for leveling ceilings.

To lay curved elements in single- and multi-level structures, you need a gypsum plasterboard grade reinforced with fiberglass. The standard thickness of such plates does not exceed 6.5 mm; they are bent exclusively along their length, without making cuts or wetting. Regardless of the type, the type of edge of the product is additionally taken into account. Sheets with UK and PLUK (thinned and semicircular) are best suited. Options with straight ends are used only in multilayer systems or for installations that do not require laying joints. The surface and seams are covered with a thin layer of plaster.

Marking the ceiling before leveling

Work begins after clearing and removing crumbling building materials and treating with antiseptic primers. At this stage, one or more horizontal lines (based on the number of protrusions) are laid along the perimeter of the walls using a water or laser level. If all the rules are followed, the straight line of the starting point will coincide with the ending point. To eliminate errors, a cord is stretched across the entire plane of the room. If it is necessary to simply level the ceiling, without complex lighting, the structure is lowered only to the profile height (i.e. 60 cm from the minimum possible point). When including spotlights in the lighting plan, the correct positioning of their housings will require at least 10-12 cm (by analogy, when insulating or soundproofing, the level depends on the thickness of this layer). Markings are carried out for direct hangers - along the central axis of the profile with an interval of 60 cm.

There is no need for additional leveling; it is carried out only with frameless fastening, which is rarely chosen. But it is recommended to seal large cracks with a solution, at least to improve insulation and moisture resistance. In both private houses and apartments, it is advisable to combine the process of leveling with plasterboard and wiring electrical communications (the wires are either laid out in the attic and brought out at the right points, or between the profile), this allows you to save space. In bathrooms, kitchens and other rooms with high humidity, the cable is placed in a box; in any case, it is securely fixed. All wiring work is completed before the gypsum board sheathing begins.

Alignment and installation technology

The standard scheme of actions includes the following stages: assessment of the condition of the surface and its preparation → drawing up a plan for the placement of sheets, profiles and lamps, calculation of materials → marking → wiring → installing the frame → covering the structure → processing joints and plastering, decorative finishing. The fastening of the support begins from the walls - the lower part of the guide product is laid strictly along the marked line and fixed with dowels in increments of no more than 45 cm. Next, direct hangers are installed; when assembling multi-tiered projects, anchor varieties are used. After this, a profile is attached to them - 5 mm shorter than the distance between the walls to simplify its installation in the guides.

At this stage, it is important to level the plane as best as possible; level control is carried out when fixing each segment; to avoid errors, a fishing line is stretched between the walls. It is recommended to place the first profile at a distance of 30 cm from the edge, no more; in problem areas, its step is increased. It is also worth reducing the interval from 60 to 40 cm when using specialized brands - fire and moisture resistant. The increase is mandatory when the thickness of the plasterboard for the ceiling is over 12.5 mm.

Exclusively longitudinal placement is not enough: transverse inserts are required at all joints, and we should not forget about displacement. The most reliable option would be a staggered profile arrangement.

The easiest way to install the transverse elements of the frame is with the help of “crabs”; if they are absent in the required areas, the metal is cut and bent, but this method takes a lot of time. The installation of the frame is considered complete after fixing all the inserts with self-tapping screws and checking the level again.

Finishing with plasterboard begins from the corners (all whole elements are placed at the edges, segments - towards the center). All holes for lamps are prepared in advance, after cutting the gypsum board. This stage requires the strength of at least two people; lifting and fixing slabs of standard size and weight is extremely difficult on your own. For fastening to the frame, metal self-tapping screws are used, spaced in increments of no more than 25 cm. Their caps are recessed by 1-2 mm, protrusions are not allowed. During the sheathing, a small gap is left between adjacent sheets (within 5 mm).

The final stage is the finishing of joints and surfaces: the material is primed, the seams are reinforced with fiberglass or paper tape and filled with putty, several times if necessary. The holes for the self-tapping screws are covered with cross-shaped movements, and excess mortar in any areas is removed immediately. After drying, the slabs are lightly cleaned and covered with a thin layer of finish; when preparing plasterboard ceilings in private houses and apartments for painting, putty is applied twice, in this case the surface is carefully sanded.

When planning home renovations, they answer the questions: what material is best to use, what thickness of plasterboard for the ceiling is suitable, how much to buy. Even minor details are taken into account.

In the current building materials market, manufacturers offer consumers to divide drywall according to its properties and scope of application.

Different types of material depending on composition

• Ordinary (gypsum plasterboard). This type consists of plaster and sheets of thick cardboard. It is mostly gray in color and weighs little, which is convenient when working at elevated positions. GCR has a low cost because there are no additional properties. It is used in rooms where there is no high humidity. Typically, the sheet is used for cladding walls, frame ceilings, and the construction of partitions. It is easily subject to further processing, such as wallpapering. GCR is made from environmentally friendly materials, therefore it is completely safe for people.
• Fire resistant (GKLO). This material can withstand high levels of heat. This feature suggests that this type of drywall is installed near fireplaces or other fire-hazardous structures. With its help, additional partitions are erected in the room, the walls and ceilings of country houses are decorated to reduce the speed of the advance of open fire.
• Moisture resistant (GKLV). The peculiarity of this type of drywall is that its structure contains specific elements that make it possible to reduce the threshold for water absorption. Thanks to this, the material does not lose its appearance and does not swell. It has been noticed that mold and mildew do not form on such drywall. It is intended for covering rooms with high levels of humidity. For example, a bathroom or in a country house where there is dampness.
• Fire and moisture resistant (GKLVO). This is the optimal type of material, since it is not afraid of exposure to either moisture or temperature.

Types of drywall by size, which one and where to use it

If we talk about the physical properties of drywall, then one sheet can cover three square meters of surface, and the weight is approximately 30 kg.

Depending on the thickness of the material, there are three categories:

• Arched. The thinnest material, its thickness is 6.5 mm. It bends and fulfills the designer’s original ideas, decorating doorways and niches;
• Ceiling. Plasterboard of medium thickness (from 8 to 9.5 mm). This sheet of material is lighter than regular gypsum board; it is used when installing a suspended ceiling.
• Wall. Thickness – up to 12.5 mm. This material is used for finishing walls, niches or partitions.

Ceiling gypsum plasterboard is an economical option because it has a simple and lightweight composition.

As can be seen from the information above, before proceeding with the installation of a plasterboard ceiling, it is determined which material to choose and which problem to solve.

How to calculate the consumption of plasterboard for the ceiling

The main mistake of novice builders is that they select the wrong sizes of drywall sheets. Because of this, many seams are formed. To install the ceiling correctly, the master will select the optimal length of the material and place it on the surface according to the rules. To do this you will need several sizes.

Beginners are advised to draw a diagram of the planes on which drywall will later be installed, as shown in the figure above. It is better to do this on a sheet of paper in a box to select the required scale. By graphically placing the material, you can see what size is needed and how much drywall will be spent.

If there is no time for such calculations, then they purchase material based on the total surface area, adding up to 20% “in reserve.”

It is taken into account that if the ceiling is 280 cm wide, then the best option is to use 300 cm of sheet. A mistake in this case would be to install 250 cm of material with the missing 30 cm attached to it. This method will reduce the number of profiles used, securely fix the structure, and save time allotted for work. The ceiling will look aesthetically pleasing due to the absence of many seams and joints.

Important aspects when installing gypsum boards

Drywall is installed in two ways:

• Glue directly to the surface. A special glue containing gypsum is used. In this case, the plane is leveled to a smooth state without differences.
• If there are unevenness or other defects on the ceiling, the gypsum board is mounted on a metal or wooden frame. And the drywall is attached to it with screws.

Sometimes it is necessary to make a bend from a plasterboard sheet. To do this, it is pre-moistened, fixed to the template and left to dry. In such cases, use a special roller with metal needles. By passing it along the surface of the plasterboard, small holes are formed through which moisture passes better.

It should be noted that the joints of the sheets fall on the frame bar so that cracks do not form in this place.

After installation, the drywall is cleaned of dirt, dust and excessive roughness. Then it is covered with a primer, after which it dries, either wallpaper is pasted or plaster is applied.