The unique properties of wood contribute to its widespread use in construction. Wood is subject to rapid fire. Fire protection of wooden structures is the most important stage in the implementation of a package of measures to prevent fires in houses and structures, where the walls, roofing, ceilings and internal coating of rooms are made of wood.
What are flame retardants
Fire retardants are called flame retardants. They prevent ignition, slow down the burning of already flared structures. Wooden parts are impregnated, painted or lubricated with flame retardants.
When heated, they evaporate in the form of stable compounds that actively cool the material. The burnt wood layer becomes an insurmountable barrier to the penetration of oxygen into the massif. At the same time, heat is removed deep into the structure, which prevents smoldering.
The types and use of flame retardants are regulated by regulatory documents.
Normative documents
To impart fire-resistant qualities to the supporting wooden elements of buildings and structures, norms and rules for the operation of wooden structures have been developed. They are specified in SNiP 21-01-97, GOST 30402, 30244 and Fire Safety Rules. The documentation contains requirements for the protection of wooden structures with fireproof impregnations. Each facility is assigned a fire certificate.
Classification of flame retardants
Fire retardant compositions (OS), in accordance with their characteristics, are divided into groups by type, operating conditions, level of resistance to aggressive environments and the degree of penetration into the structure of the material.
Types of flame retardants
Lucky
Film-forming varnishes are a type of aqueous solution or organic suspension. The groups of solutions are flame retardants, plasticizers, tints and other chemicals. The emulsion creates a colorless heat-resistant film on the surface of the structure.
Paints
Paints consisting of a heterogeneous mixture of flame retardants and pigments form fire-resistant coatings of wooden structures. Paints produce various colors. Hardeners, plasticizers, and other components are added to the fire retardant.
Pastes
Pastes are composite coating agents. In composition, they are similar to paints, except that the agents are applied in a thicker layer. Fire-retardant treatment of wooden structures with pastes creates an non-flammable barrier to open fire.
Impregnation
The solutions consist of a mixture of flame retardants with antiseptics. Impregnations do not form a film coating, but penetrate the structure of a tree, forming a heat-resistant shell. The compositions are divided into means of superficial and deep penetration.
Combined formulations
Means represent compositions of several types of fire protection. Each wood is applied alternately.
OS operating conditions
Wooden structures in specific operating conditions need fire treatment with certain substances:
- formulations for the treatment of wooden structures operated in open space or under a canopy must take into account the local climate. This applies to temperature fluctuations, humidity levels in the area;
- coatings and impregnations for wood in unheated rooms. Wooden parts are treated with flame retardants, where, due to the confined space, changes in temperature and humidity level of the ambient air are insignificant;
- OS for heated rooms, enclosed spaces with artificial microclimate. The compositions provide fire safety of structures in a constant positive temperature and humidity level of about 70%.
OS Stability
Fire retardants for resistance to aggressive environments are persistent and unstable.
Penetration rate
The indicator relates to an impregnating composition. Impregnations are superficial and deep penetration.
Fire protection performance criteria
Fire protection of wood is divided into three categories of action:
- Prevention of the danger of wood fire.
- The attenuation of combustion at the initial stage.
- Passive localization of foci.
The choice of fire protection of wooden structures
The selection of heat-resistant compounds for the treatment of wood structures depends on factors:
- the location of structures made of wooden elements - in an open area, under a roof or in a confined space;
- requirements of the Fire Safety Rules and regulatory documents (SNiPs and GOSTs);
- structural processing methods;
- the cost of flame retardants and production work.
Refractory varnishes
The effectiveness of varnishes to protect against the ignition of wooden structures is great. If there is a risk of fire, the varnish heats up and turns into a ceramic-like insulating shell. The heat-resistant film emits inert gases that block the access of oxygen to the combustion zone.
Refractory varnish has several advantages:
- gas tightness of the shell;
- the natural color and texture of the wood cut practically do not change;
- no smell;
- water-soluble varnish base eliminates the use of organic solvents;
- not toxic.
Apply varnish with a roller or brush crosswise. You can use a spray gun. The first coating layer should dry after 8-12 hours. The following layers of varnish are applied at intervals of 4-6 hours.
Popular fire retardants based on varnish:
Stubiterm
The product is treated with MDF, particleboard, fiberboard and parquet board. It is used to reduce fire hazard. Consumption rate - 330 g / m2. Preserves properties for 10 years.
Lacron Lac
Available for sale in plastic containers. Lacron is effective as a fireproof coating of wood indoors and outdoors under the protection of a canopy.
Shield-1
Means Shield-1 is applied to wood and products based on it. OS is used to handle internal fencing and attic floor structures.
Negorin Luck
Lacquer is used to cover elements of walls, floors and ceilings made of wood-containing materials. It is delivered to construction stores in plastic cans with a capacity of 5 to 30 liters.
The domestic industry also produces other heat-resistant varnishes.
Fire retardant paints
The purpose of paints is the creation of a heat-protective layer on the surface of wooden elements under the influence of the combustion temperature. Expanded shell increases in volume, tens of times greater than the original thickness of the paint. The neoplasm acquires the qualities of a heat shield that does not allow heating of the solid wood from the inside. This allows you to gain time before the arrival of the fire brigade.
Fire retardants that are part of refractory paints contain magnesium and aluminum hydroxides. The OS not only remains on the surface, but also penetrates the structure of wood. The composition of paints includes antiseptics that prevent the occurrence of fungal and mold formations.
Before painting, the tree is cleaned of impurities. Organic solvents remove oil and greasy layers.
Neomid
Fire-retardant paint is supplied in plastic containers from 5 to 30 liters. The manufacturer makes several varieties of water-soluble paint for processing wooden structures in the open, under a canopy and indoors.
Bionic House
The company produces high-quality paint, which has good adhesion, is quickly absorbed into the wood mass. The wooden constructions processed by it do not lose their flame retardant properties for 20 years. For wood, paint is available under the name Fireproof Coating.
Spray paint Pro Sto
The product processes concrete, metal and wood surfaces. The temperature regime of aerosol application is from +5 ˚C to +25 25C. Drying time is 3 minutes. Black acrylic paint is sold in 250 ml cans.
The range of refractory paints in the building materials market is wide. OS of this category belong to colorless aqueous solutions. To obtain the desired color, add the appropriate color to the paint.
Impregnation
Impregnations, in addition to flame retardant properties, have the qualities of antiseptics. The compositions do not leave marks on the surface of the wood. The substance penetrates deep into the structure of the massif.
Various types of impregnations are intended for processing the material under certain operating conditions of structures. The main group of impregnations is universal in nature. Pirilax is effective for treating wooden surfaces that are in difficult operating conditions - in unventilated enclosed spaces with a high level of humidity. Pirilax impregnation is used as fire protection of ceilings, exterior fences of the house, frontal part of the roof in wooden houses. The tool is impregnated with rafter structures, beams, logs, floor boards from the back and the crowns of the baths.
Pirilax protects the wood from ignition and interrupts the progress of the fire during a fire. OS prevents the development of fungal, mold formations and destroys the wood-beetle beetle. Bioprene Pirilax produce more than 10 species in containers of various sizes. Prilax-coated wooden structures do not crack, which significantly slows down the aging of the material.
Wuprotek
Wood, impregnated with Vuprotek, forms a non-combustible foamed shell on burning when burning. Inert gases are released. They prevent oxygen from entering the ignition zone.
If the fire was of a short-term nature, then to continue the operation of the structure it will be enough to remove the caramelized layering from the surface.
Wuprotek goes on sale in two types. The finished solution is sold in a plastic container. The powder mixture is delivered to the distribution network in polymer bags.
The powder is diluted with hot water (+60 ˚С) in a ratio of 1: 2.5. The tool is applied to structural elements with a brush or spray gun. To ensure the effectiveness of fire protection category 1, the rate of consumption of water emulsion per 1 m2 the surface of the object is 0.6 liters. Wuprotek is applied in three layers. Intermediate drying is about 6 hours. Processing is carried out at an ambient temperature not lower than +20 ˚С.
The OS manufacturer guarantees the preservation of the refractory qualities of the object for 10 years when processed with a finished composition and 3 years when using a powder solution. Fire retardant is produced in three versions: Vuprotek-1, Vuprotek-2, Vuprotek-3 and MS. Each tool is designed for a certain degree of fire protection, taking into account the operating conditions of the structures.
Stucco Neosprey
Effectively flame retardant neospray. OS is used to create a refractory coating of steel, concrete and wooden structures. The tool is a non-combustible shell with high thermal insulation properties. During a fire, it protects the structure from the effects of heat flux and open flame for 2–4 hours.
In the combustion zone, Neosprey does not change the appearance, does not crack and does not exfoliate from wood. OS does not contain harmful impurities. The shell resembles plaster “under a fur coat”.
The neospray protective coating is applied by gunning with a plastering unit. Work is carried out at a temperature not lower than +5 ˚С. The shell hardens 3-4 hours after application. The final strength Neosprey acquires after 30 days.