Fire-resistant fireproof plasterboard: types and requirements

Following the beautiful, alluring concept of “European-quality renovation” and other miracle finishing materials, technologies supposedly unknown in the Soviet Union; The magic word “plasterboard” has entered the everyday life of people seeking to redesign or renovate their apartment or private residential building.

Architects and designers, sales consultants of trade organizations selling sheet building materials, foremen of enterprises, organizations involved in interior decoration of office and residential premises, foremen of self-employed workers unanimously with amazing confidence told the amazed owners of real estate that plasterboard is moisture-resistant, fire-resistant, and Moreover, it is a very light material compared to brick and reinforced concrete structures. Therefore, they can do anything up to the construction of fire partitions, the allocation of fire compartments and sections in buildings and structures using it.

Today, when the advertising frenzy has somewhat subsided, it is worth taking a closer look at all the advantages and disadvantages of this, without a doubt, good construction and finishing material in terms of ensuring fire safety measures and compliance with regulatory requirements when using it.

Fireproof plasterboard

Does drywall burn?

Different types of drywall have different fire-technical characteristics, so one type of drywall can be confidently considered fire-resistant, while the other is still a flammable material.

It's easy to understand: do a simple analysis. Regular drywall consists of gypsum and cardboard. Gypsum is a material that will not burn, but is only subject to destruction over time of burning. But cardboard can burn, but even then it is too tightly connected to the gypsum core, there is no air between this connection, so the cardboard will not burn, but will char.

Drywall is a highly environmentally friendly material, so when charred, no harmful substances will be released into the air.

Why then buy gypsum plasterboard, drywall with fire-resistant characteristics? It's simple - it resists open fire much longer.

Heat resistance of gypsum plasterboard

The main differences between heat-resistant gypsum board and standard

It is not difficult to distinguish heat-resistant material from ordinary material, since it has a number of distinctive features:

• The density of the described material is 850 kg/m3 (standard – 800 kg/m3)
• Gray or pink sheet of fire-resistant gypsum has red markings
• The thermal conductivity index is 0.22 W/Mk, while the classic analogue is 0.35 W/Mk
• In addition to reinforcing additives for additional fire protection, the cardboard layer of sheets is covered with several layers of fire-resistant impregnation

Fire-resistant HA can withstand continuous exposure to an open flame for no more than 30 minutes. After this time, the material begins to deteriorate.

Unlike the standard type, heat-resistant drywall can be installed in industrial premises, which are characterized by unstable humidity levels and elevated temperatures.

Types of drywall products

The moisture-resistant type of plasterboard plates is designated by the abbreviation GKLV (according to the new standard - the letter H), has outer layers of green color with blue markings.
The ability to repel water is explained by the presence of special components in the gypsum core, in addition to which antifungal agents are added to the product.

There is a modification of plasterboard plates with increased fire resistance, achieved by introducing additives with specific properties. Such sheets are designated by the abbreviation GKLO, and according to the new standard by the letter F.

It is easy to distinguish the products by the light pink color of the cardboard shell and the red markings on them.

Products marked with GKLVO, fortified with several types of additives, are particularly resistant to fire and have an increased ability to repel water. The surface of such drywall is painted green and marked with red markings.

New types of gypsum sheets with international markings P, D, R, I are appearing on the modern market. They have a specific structure, their own fire resistance limit and other properties. Such drywall is intended for strictly designated loads and types of work.

There is a separate group of products made from a homogeneous mixture of gypsum with cellulose fibers, which are called gypsum fiber sheets and are abbreviated GVL.

Fire safety certificate

And here is only strict information on the fire safety certificate of drywall.

GKL, GKLO, GKLV, GKLVO have:

• Smoke generating ability group – D1;
• Flammability group - G1;
• Flammability group – B3;
• Toxicity group – T1.

But even based on this data, on certain recommendations on where and when to use what type of drywall, each time you need to ideally select the type of drywall.

Fire safety classes

Fire resistance limit

All types of drywall (gypsum board) have a high fire resistance limit due to the high concentration of hydrated calcium sulfate - gypsum. When heated, water vapor separates from the mineral salt, thus lowering the surface temperature.

The limit of fire-resistant ability is quantified by the length of time before the onset of a condition in which the integrity, mechanical strength, and heat-insulating ability of the structure are lost.

Standard sheets exhibit heat resistance for 20 minutes. The fire resistance of products with an additional letter O in the marking is significantly higher. Such sheets can withstand open flames for up to 55 minutes, and retain their fire-fighting properties for 25 minutes.

The fire resistance limit of GVLV products during fires is higher than that of conventional drywall, which is explained by the uniform distribution of cellulose fibers between the gypsum particles. As a result, the organic component heats up much more slowly and is practically not destroyed.

Information confirming the non-flammability of all types of plasterboard is displayed in certificates, which indicate that they belong to group G1 in terms of flammability, B2 in terms of flammability, tendency to form smoke - D1, and toxicity of products formed when the temperature rises - T1.

The totality of data confirming the high fire resistance limit allows us to confidently use plasterboard for renovation work in all types of premises.

What temperature can drywall withstand?

Drywall can withstand open flames in a fire. As mentioned above, gypsum itself does not burn, and after the cardboard burns, the core will only collapse.

Drywall will withstand any possible negative temperature that occurs in natural conditions.

And in order to increase the fire-resistant qualities, two-layer partitions are made in plasterboard, and the cardboard between the two sheets in them will not fade longer.

Fire resistance test

Characteristics of fireproof plasterboard

The characteristics of this material can be useful if you are in doubt which type of drywall is suitable in your case.

Fireproof plasterboard:

• Differs in sheet thickness of twelve and a half mm;
• The markings on it are red;
• The core of the material contains reinforcing additives;
• The frame here is not only cardboard, but reinforcing fibers, so the sheet, after charring the cardboard, continues to resist fire.

Fire safety class - KMO (non-flammable material).

Flammability

In addition to flammability classes, flammability characteristics are of great importance. They are calculated based on the values ​​of the maximum heat flux density. There are three categories:

• IN 1. Refractory substances per 1 m2 have thermal parameters of no more than 35 kW.
• AT 2. Moderately flammable substances have indicators per 1 m2 from 20 to 35 kW.
• AT 3. Highly flammable fire hazardous materials have a heat flow density of up to 20 kW.

In addition to flammability and flammability, the fire hazard of materials is determined by smoke-forming ability (divided into D1-D3), the possibility of flame spreading over the surface (RP1-RP4) and the degree of toxicity of combustion products (T1-T4).

For clarity, we present the definitions of fire safety classes in a tabular structure.

Fire test

Compound

Fire-resistant plasterboard consists of:

• gypsum dihydrate, filament threads and special organic active substances – about 93%
• cardboard covering – 6%
• moisture – about 1%

The filler of the gypsum refractory sheet is reinforced with filament glass fiber, the length of which ranges from 3 to 30 mm. Thanks to this, when exposed to an open flame, the material is able to remain stable for a long time, withstanding the structural load placed on it without destroying the core structure.

Drywall is fastened using special adhesives - mastics. It can also be fixed to the profile sheathing with screws or self-tapping screws every 10–20 cm.

The gypsum filler contains fire-resistant additives, and the crystal lattice contains a certain percentage of water molecules. This feature allows the layers to accumulate moisture without deforming the material. During a decrease in humidity levels, the described fire-resistant cladding helps to stabilize the microclimatic parameters indoors.

Fireproof additives

Test procedure

It is carried out when serial commercial products are put into production, and then periodically - at least once a quarter; and also when changes are made to the production process, new materials and additives are introduced into the recipes of raw materials. According to GOST, the test procedure for fire resistance is similar, but according to GOST 32614 it is carried out under more stringent conditions:

• Take three sheets of plasterboard or 6 sheets of GSP from a batch of commercial products.
• Two gas burners are directed onto the cut sample to achieve a value of 800±30℃ - for gypsum plasterboard until destruction, measuring resistance to open flame in minutes, normally not less than 20 minutes; 1000±50℃ – for GSP for 15 minutes (normal) or until destruction.
• All samples are subjected to tests, and if at least one of them does not pass them, losing its integrity, collapsing into two or more parts; then the tests are considered unsatisfactory, the batch of GKLO, GKLVO or GSP-DF cannot be accepted as a fireproof/fire-resistant material.

Fireproof plasterboard Knauf

The high quality and class of this plasterboard allow us to expand the scope of its application.

Characteristics:

• Not only non-flammable, but also breathable material;
• Sheet after sheet is placed quickly - easy installation;
• Knauf is an environmentally friendly, clean and safe material;
• It is odorless, and its leaf does not conduct electricity;
• Knauf fire-resistant sheet has sound-absorbing characteristics.

The high quality of the material and ease of use are confirmed by the good reputation of the brand.

Production technology and its impact on flammability characteristics

According to Wikipedia, mineral materials are non-flammable. These are ceramics, natural stone, reinforced concrete, glass, brick and analogues. But, if additives of a different nature are used in production, then the fire safety parameters change. Modern technologies involve the widespread use of polymer and organic additives. Depending on the proportions of flammable and non-flammable components in the composition, the parameters of the building material can be transformed to G1, and even to G4 flammability class.

Scope of fire-resistant gypsum plasterboard

The use of standard drywall in rooms with increased requirements for fire resistance and non-flammability is irrational, since the material quickly loses its properties when in contact with high temperatures. Therefore, in rooms with increased fire safety requirements, it is best to use fire-resistant plasterboard.

It is most often used for:

• finishing of industrial premises and home boiler rooms
• cladding for domestic fireplaces
• production of interior partitions, inside of which electrical cables are supposed to be laid
• design of children's rooms and public spaces
• decoration and finishing of educational institutions of various levels of accreditation
• manufacturing of household air ducts
• interior decoration of wooden houses, country houses and cottages.

Room decoration

Manufacturer's choice

Drywall from the German brand Knauf is considered the most fire-resistant due to its surface impregnated with a special fire-resistant compound. The fire resistance limit of Knauf plasterboard is 60 minutes, after which destruction begins. Characteristics of Knauf heat-resistant plasterboard include the fact that it does not conduct electric current in the event of heavy water flooding from neighbors above or leaking water pipes.

Knauf fire-resistant plasterboard has the character of environmental safety, water resistance, and fire resistance properties. Fireproof plasterboard is used:

• for fireplace
• suspended ceilings
• partitions in private houses
• in high-traffic public places
• in schools, childcare centers

The product is the most in demand on the market, 2/3 of gypsum plasterboards are sold with the Knauf trademark.

in Volgograd produces fire-resistant plasterboard with a high degree of fire resistance - 45-50 minutes. The material costs a little less than imported analogues.

The beveled edge of heat-resistant boards with a line applied by the Rigips company (Rigips) facilitates the marking and installation of fire-resistant sheets.

from the city of Saransk supplies fire-resistant plasterboard with increased strength and flexibility. Heat-resistant plasterboard has high class A characteristics, environmental safety and high dimensional accuracy and a refined edge. The fire resistance limit of Magma plasterboard is 45 minutes after the start of ignition. Fire retardant blocks are available in pink and gray colors.

They cover schools, walls, ceilings of children's rooms, fire-hazardous fireplaces, and combustible bases with fireproof plasterboard.

Comparative table of prices for fire-resistant plasterboard brands on the Russian trade market.

As can be seen from the table, the difference in prices is insignificant. More expensive are the imported analogues Knauf, GYPROC, Rigips.

How to improve the fireproof qualities of drywall

You can attach plasterboard in several layers to a steel frame: the second layer doubles the fire resistance of the structure.

Remember that both fasteners and insulation must also have a certain fire rating to match the fire-resistant functions of the future structure.

Fire-resistant drywall has the task of not only increasing the resistance of the structure to fire, but also the possibility of using the material in the construction of the same shafts and air ducts.

Installation subtleties

Having decided whether the drywall burns or not, you can begin installation. Surfaces are cleaned of old finishes, traces of fungus and mold are removed, and primed. The building material is mounted on the frame, so before the procedure, markings are made for the fasteners of the blocks.

Assemble the profile sheathing. As a “skeleton” for fire-resistant drywall, metal slats made of reinforced (alloy) steel should be used. It is prohibited to screw sheets to wood. The slightest spark from the wiring will cause a fire, which will defeat the purpose of all protective procedures. Partitions made of combustible wood are treated with a fire-fighting solution.

Lathing for drywall Source stroyday.com