Fireplace in a wooden house

1. Introduction. Basic concepts. This article discusses the basic requirements for the device is closed fireplace that is specific to wooden houses. As the wooden houses are considered "warm" season at home with the possibility of living, in which the load-bearing walls, partitions, floors, load-bearing roof structures made of wood. These homes may include curbs, home from a bar, home of laminated veneer lumber, logs, karkasnoschitovye home. As a fireplace, consider the whole system, consisting of a closed furnace factory-built, with flue gas temperature not exceeding 400 grad.S, modern multi-flue, with internal thermal insulation layer of basalt wool, which provides outdoor temperature on the outer surface of the chimney is not more than 85 deg., with free circulation of air around the chimney, the chimney of the single-pipe stainless steel, minimum thickness. 0,5 mm. or 2-mm tubes of ordinary steel and stone, non-combustible cladding. We consider the option of installing a fireplace in its entirety only inside the house. 2. Existing building codes. Modern fire standards, as expressed in the Russian regulations (SNIP 41-01-2003 Heating, Ventilation and Air Conditioning, requirements VDPO) designed primarily for brick chimney and an outdoor fireplace made of bricks and does not correspond to the use of modern thermal insulation and structural materials, design and construction of chimneys, which are more than 30 years have been successfully used in Western Europe and about 10 years into practice in Russia. For example in the existing SNIP 41-01-2003 repeated the old claim that "... the size razdelok furnaces and smoke channels, taking into account the thickness of the walls of the furnace should be equal ... 380 mm - up structures that are protected in accordance with 6.6.236). This means that when the chimney with an inner diameter of 200 mm, the distance between the wooden beams or under what condition can not be less than 960mm. Unfortunately, at the design stage, in most cases does not provide adequate space for the chimney. Reinforced floors, modern wood houses are built, usually of the beams, arranged in increments of up to 500h500mm 700h700 mm. Therefore, literal compliance with this requirement leads to costly rework designs intercommunication floor modern wooden buildings. In addition, this requirement is applicable to a masonry chimney for stationary furnaces, largely meaningless to modern multi-flues, designed specifically for indoor fireplaces. Multi-layer construction and "step" seam in modern chimneys, chimney construction is guaranteed to protect against accidental escape of sparks across the seam. And the use of basalt wool insulation required thickness in the intermediate layer between the outer surface of the chimney and wooden beams guarantees the maximum permissible temperature of the junction of wooden structures to the outer surface of the chimney. Currently Gosstroy principal decision on the gradual transition to the 2006-2008 year at the EU-wide building codes, developed primarily based on the DIN. These standards must comply with all the modern furnaces and chimneys are made in a united Europe and sold in the European market. These standards seek to meet most of the leading Russian engineering and construction firms involved in the design and installation of fireplaces and chimneys. 3. General requirements for the installation of the fireplace. Detached house with no fireplace or stove is now almost can not imagine. Any fire in the classic sense consists of three main elements: the furnace, flue and chimney between them. Veneer is usually a decoration and in terms of fire safety can be neglected. Except for one fundamental requirement - fireplace and wall must be placed on a common foundation. Such positioning should not allow any progress to each other. Individual Houses of wood: solid timber, laminated veneer lumber, logs, natural logs, frame - each year are becoming more widespread in construction. Their main advantage compared to the stone houses is more favorable for healthy living, with good thermal characteristics. However, along with indisputable advantages, the wooden houses have, perhaps, most significant drawback - high fire danger. Increased fire danger due to both structural characteristics of wooden houses - shrinkage, and as a result of shrinkage, the possible damage to the elements fire, and the use of bearing and protecting designs of flammable materials. If you are installing any fireplace or stove in a building required to comply strictly with fire prevention requirements, in particular, is important when installing a fireplace in a wooden house. You can cite two main factors risk of fire in wooden houses associated with the construction and operation of fire 3.1. Risk factors associated with shrinkage of the wooden house. Built a wooden house, depending on the structure and moisture of the materials shrink by 15-25 cm during the first 3 years of operation. And up to 70% shrinkage occurs during the first heating season. Therefore advisable to install a fireplace in a wooden house, usually one year after the assembly of the house. In this case, do not have often enough (once in every two months as rainfall house move down atmosferozaschitny apron for serving on the roof part of the chimney. Do not also have to perform complex design activities in a thermal jacket fireplace, heat and sound insulation of floors and intercommunication roof. These activities should provide a significant (up to 15-25 cm) free vertical movement of the structural elements of fire with respect to construction of the house. Even after the final shrinkage of the wooden house height of the walls, depending on seasonal humidity may increase or decrease by 3-5 cm therefore in any case, all elements of the fireplace should be independent of the vertical movements of elements of home construction. bearing and protecting designs of wooden houses: the walls, floors, roof construction, additional termozvukozaschitnye cuts in place through the passage of flue overlap should be free to move vertically on the elements of fire: the foundation under fireplace facings, hearths, chimney, flue, fire protective wall atmosferozaschitnyh apron on the outside of the chimney. fireplace and the house can be made on the same foundation, but in this case, bands and banners, horizontal fixing the chimney, the elements of thermal and sound insulation in the intercommunication ceilings, interior partitions and walls are home construction and must move with respect to the fireplace, along with bearing and enclosing elements. 3.2. Risk factors associated with the flammability adjacent to the fire, bearing and protecting designs of wooden houses. the most dangerous place in the device fireplace and chimney are places adjacency to the bearing and protecting designs at home. According to the requirements of fire safety the maximum permissible temperature at the contact surface elements fireplaces, chimneys and chimney with wooden structures shall not exceed 85 deg. C.-site furnace and chimney liner adjacent wooden wall protects the mobile vertical ( with respect to the wall) the fire wall on the entire height of setting the fire. These walls are performed, usually made of foam concrete, plaster elements, brick with a thickness of min. 100 mm with an additional internal insulation thickness of basalt wool min. 30 mm in the plane of the junction furnace lining and shell . Besides the internal space fireplace, a limited furnace lining, a protective wall and a decorative cover, should have a permanent outside air ventilation. Cover the floor under the furnace, and at a distance of 500 mm in front of the firebox and the width of 300 mm per side should be made of noncombustible Materials 3.3.. Forms of chimneys. An important factor in the risk of fire in a wooden house is the chimney. The most vulnerable area - the place of his passage through the construction of floors and intercommunication through the design of the roof. Depending on the application form the chimney, vary the minimum distances in the construction of floors and coatings building. The most common now among the views of suspended multilayer chimney flues are made of 2-Contour tubes of heat-and acid-resistant stainless steel. These chimneys are quite durable, inexpensive, have little of their own weight - up to 10 kg / lm and not require the device's own foundation. The maximum guarantee period for such chimneys give the firm «RAAB» - 10 years. The cost of 1 m.p.takogo chimney-mounted with a thickness of Internal Heat protective layer of 60 mm is 250-350 dollars. clients prefer a more durable construction suspended chimney may choose a more reliable option - a system of «Kerastar», produced by German company «Schiedel». The outer contour and an interim 60-mm layer of insulation from the basalt wool similar to flue type RAAB. The inner layer of the system is made of fireclay pipes having substantially greater resistance to aggressive compounds (tar, acidic compounds, etc.) contained in the outgoing gases. The warranty period of such chimney extended up to 30 years. The disadvantages of this system include its higher cost do500-$ 600 / lm with installation and more weight of 25-30 kg / mp. Suspended chimneys in wooden houses are attached exclusively to the joists protective wall. They can not rely on the hearth and facing, and should be free to move vertically with respect to load-bearing structures at home. The most reliable are the indigenous chimneys chimneys , based on shared with the furnace or furnace and the house foundation, made of 3-layer elements. The inner layer, with primary heat load is made of fireclay pipe thickness 20mm. interim layer of basalt wool, 30 mm thick, outer layer - hard shell of the chimney "of expanded clay-light-concrete blocks. Depending on the height of free-standing chimney, the design is reinforced by 4 corners of the reinforcement bars, which provide additional rigidity. Producers of such chimneys offer a guarantee on their products up to 30 years (Schiedel, Plewa, Hart ). Such chimneys are characterized by a relatively low price of 250-350 U.S. $ / mp. with the installation. outer surface of the chimney simply amenable to finish. These chimneys provide internal ventilation design. Such a solution prevents both condensation and lowers the temperature at the outer surface of the chimney. The disadvantages of such chimney can be attributed to their large weight to 120 kg / mp. and the inability to flex within the home. One of the promising types of chimneys is a design developed by «RAAB», where the inner tube is made of stainless steel exterior contour of the vermiculite (40mm) and the intermediate of basalt wool (30mm). This chimney has a number of advantages. It can be bent and, if necessary, suspended, like chimneys made of stainless steel. This chimney has considerable rigidity. Its main assets are also relatively low price - about 200-300 U.S. $ / mp. with the installation. outer surface of the chimney is easy to finish. 1m.p. weight of the chimney is about 40 kg / mp. 1mp cost. Chimney with installation depends on who performs any additional work (Client or Contractor): - Implementation of holes in floors and cover - to isolate the building structures at the site of passage through the flue overlap - to ensure access to the roof. Example. The house is supposed to install 10 - meter root chimney «Uni» production «Schiedel». If, in accordance with the project installation, all preparatory work will fulfill customer, the installation of a chimney contractor performed an average of 2 days and the cost of the chimney with the installation work will be 2500-2700 euros per 10 m n. or 250-270 euro per 1 lm If additional work performed by the contractor, the period is increasing by an average of 1 day and the cost of the chimney with the implementation of construction works will be 3500-3700 euros for 10mp or 350-370 euros per 1mp 3.4.. Thermal insulation floor and roof constructions where it passes through their chimney. Depending on the passage of the chimney through the construction of overlap: "vented" or "deaf", vary the minimum allowable size of the holes in the ceiling. The best cooler is svobodnotsirkuliruyuschy along the trunk of the chimney air . In "vented" version of the passage of the chimney through the ceiling, freely circulating external air cools the outer surface of the chimney. The maximum temperature of the circulating air does not exceed 60 deg. C. This possibility appears when thermally insulated to arrange interim housing between the floor beams and barrel chimney. In a place pass through the chimney floor air circulates freely between the outer contour of the chimney and a layer of insulation jacket. guard should move freely in the vertical with respect to floor beams. Barrel chimney must be rigidly fixed to structural elements of the casing. The main requirement for the implementation of such an option is to prevent the free circulation of air from lower floors to the top floor in a place of passage through the chimney overlap. With this decision the total distance "from the smoke to a tree (from the inner surface of the chimney and the adjacent wooden elements) can be reduced to 120 mm. The distance between the wooden beams with an internal diameter of the chimney 200 mm can be as low as 440 mm. drawback "vented" option is the enhanced transport of dust. The design works as a cleaner, more pylegon, with all the attendant consequences: an allergy to dust, increased dryness of the air. More common is the "blind" version of the passage through the flue overlap . With such a performance space between the chimney and wooden beams fully insulated thermal and sound insulation mats. In the absence of free circulation of air in the construction of intercommunication overlapping temperature on the outer surface of the multi-flue (eg when using 2-layer pipe with inner insulation basalt wool in the 60 mm) increased to 190 deg. C. Therefore, to ensure fire safety fencing wood intercommunication overlap in the performance of this option, you must provide additional thermal insulation. The total distance from the "smoke up the tree" in this scenario, the use of rigid mineral wool to seal the space between the outer layer chimney and the wooden beams must not be less than 16 cm It has an additional thickness of insulation between the outer surface of the chimney and wooden beams should be 10 cm thick insulation between the similar design of the chimney and wooden beams should be applied at the device hanging chimney «Kerastar» production «Schiedel and «Multischachta» production «RAAB». When designing and implementing such an option chimney minimum possible distance between the wooden beams with an internal diameter of the chimney of 200 mm is 520 mm. The advantages of this embodiment of the node pass through the intercommunication overlap include good sound insulation sufficient constructive stiffness of the chimney, the absence of air currents that carry dust. shall be provided and perform activities that result in an additional layer of insulation will be free to move along with the construction of the overlap vertically with respect to the chimney. When the hard 3-layer type of chimney «UNI» production «Schiedel "due to internal temperature of the ventilation design on the outer surface of the chimney, regardless of" deaf "or" ventilated "version of the passage through the overlap does not exceed 85 deg. C. However, in violation of the free circulation of air within the chimney structure (such as getting a solution for mounting), the temperature at" blank "form on the outer surface of the chimney exceeds permissible. Therefore, in any case it is recommended to arrange around the perimeter of the chimney in the zone of passage through the overlap of additional thermal insulation from the hard basalt wool tolsch.50 mm. Between the ceiling and floor boards to keep enough distance 20mm. The minimum distance between the wooden beams will be 48 cm with inner diameter of the chimney of 200 mm. All the calculations of temperature on the outer surface of the chimney are given on the assumption that the temperature inside the chimney at the site of passage through the overlap does not exceed 400 grad.S. 4. Recommendations for choosing a chimney. When designing the flue conducted simultaneously with the design of the house, and at the design stage coordinated step ceiling beams and rafters of the roof, installation of foundations under the fireplace and chimney, then the optimal solution would be to use relatively heavy "native" 3-ply chimney «UNI», production «Schiedel» or similar structures. With a large own weight in the 100-120 kg / mp. a chimney provides the greatest rigidity, resistance to corrosion, the lowest temperature at the surface and as a consequence of the greatest fire safety. If the chimney and fireplace are provided in an already-built house is the choice chimney effect as a step installed ceiling beams and rafters of the roof pitch, and their relative positions horizontally relative to each other. If the distance between the beams is minimal, about 400 mm and can not increase it, then the only possible solution is to pass through the unit vented soffit. This decision should be performed using the chimney of the 2-contour stainless steel tubes. If the distance between the beams is sufficient for the device as "deaf" and "vented" option, then the determining factor in choosing to be the price the customer is willing to pay for the chimney. In addition should take into account the factor that bend when necessary inside the house can only chimneys with the inner loop of stainless steel or more expensive "mixed" chimneys, made of 2-Contour tubes «Kerastar» production «Schiedel» with an internal loop-fireclay 8-mm tube and outer tube of stainless steel. Indigenous chimneys type «UNI» can only be used for straight chimneys. One of the best options is the use of chimneys, made to the system «multischachta», developed by «RAAB». External box of vermiculite provides sufficient rigidity, provides additional insulation, and most importantly, as in the case of a chimney «UNI», it is possible the device virtually any exterior finish. 5. Requirements for the Protection of bearing and protecting designs related to the device chimney. Typically chimney is arranged within the design fireplace, inside the enclosure. In this case, it does not affect the fire safety of adjacent structures. However, a serious danger arises when passing chimney through the wooden wall to the location in an adjacent room chimney. In this case, all the wooden materials of walls or partitions at a distance as min.500mm from the inner surface of the chimney should be replaced with fireproof (plaster or foam concrete).. In this case, it shall be free shrinkage of the building with respect to termination node. 6. The general conclusions. Beautiful elegant fireplace, of course, the decoration of the house. relate to the fire, however, only as to the furniture It would be extremely dangerous. Failure of engineering and fire safety standards in the design and installation of fireplaces, chimneys and implementation of protective razdelok improperly from inappropriate materials can cause structural failure and cause a fire. Only cooperation with qualified professionals, both at the design stage and on stage installation, to avoid possible unpleasant consequences. Furthermore, even after professional installation fireplace should be remembered that at least 1 time a year the entire system must be checked by experts. Chimneys should be regularly cleaned of layers of soot and tar. passageways through the floor and place of the adjacency to wooden house construction inspected for possible damage to the insulation. All these requirements are particularly relevant when constructing fireplaces in wooden houses.