on their function, interior walls made of sand-lime brick are designed as load-bearing or non-load-bearing walls and, due to the high bulk density of the material, also meet increased requirements for sound insulation, fire protection and heat storage capacity. This makes them suitable as a partition wall between usage units, as a room closure of a necessary staircase or as an internal fire wall. The high stone compressive strength results in a particularly high static load capacity. Sand-lime brick interior walls are often produced as exposed masonry for visual or economic reasons.
Most types of sand-lime brick can basically be processed both as an exterior wall and as an interior wall. See encyclopedia articles► Sand-lime brick, stone types according to DIN V 106 and ► Designation of a sand-lime brick according to DIN V 106.
While exterior walls made of sand-lime brick are usually made of several layers in order to meet thermal insulation requirements, load-bearing and non-load-bearing interior walls are usually single-layered.
Sand-lime brick is also produced as exposed masonry in the interior. For a particularly high-quality look, a double-shell construction with special facing stones is recommended.
Non-load-bearing interior wall: A non-load-bearing (and non-stiffening) interior wall has no static function for the higher-level supporting structure of a building. It can be added or removed at will, even in existing buildings. From a static point of view, it is one of the payloads and can be included in the calculation via a partition wall surcharge, see lexicon article ►Partition wall surcharge.
Non-load-bearing partition walls, including their connections to adjacent components, must also demonstrably meet static requirements that are regulated in DIN 4103-1:
Load-bearing interior wall: As part of the building structure, load-bearing interior walls also serve to transfer dead loads of the building, in addition to their other tasks (e.g. room separation, fire protection and sound insulation). Even with a wall thickness of 11.5 cm, sand-lime brick can meet the requirements for a load-bearing wall. In the interior wall area, the use of sand-lime brick can thus lead to particularly economical living and usable areas.
House partition wall: Due to their high bulk density, interior walls made of sand-lime brick with a double-shell construction can also meet the requirements for increased sound insulation in accordance with DIN 4109 Supplement 2 or the VDI guideline 4100. With just two sand-lime brick walls (bulk density class 1.8), each with a thickness of 15 cm, and a separation joint of 5 cm filled with mineral fibre boards, the required 67 dB between semi-detached or terraced houses can be met. Sound insulation can be further improved by a higher bulk density class or a wall thickness ≥ 17.5 cm, see also Lexicon article ►House partition walls.
Partition walls between usage units and to the stairwell: High sound insulation requirements, but usually also fire protection requirements apply to the walls between two usage units (e.g. offices, apartments) and between a usage unit and the stairwell. The walls must be led directly under the roof cladding, e.g. under the roof tiles. If the roof structure meets the requirements for fire resistance as a room-enclosing component in accordance with the state building code, the partition wall may also connect to the underside of the correspondingly qualified layer of the roof structure.
In contrast to house partition walls, partition walls inside buildings are usually single-shelled. The sound insulation value Rw of the material sand-lime brick is sufficient to meet the requirements for single-shell apartment partition walls. The commercially available sand-lime brick constructions therefore usually do not require separate verification. However, the decisive factor here is the assessed sound insulation coefficient R'w, including flank transmission. See the encyclopedia article ► Sound insulation dimensions for separating components of solid construction and bauwion page ► 122 | Exterior walls made of sand-lime brick, sub-item sound insulation.
Heat storage capacity: Due to their high bulk density , interior walls made of sand-lime brick can make an important contribution to thermal regulation in indoor spaces by absorbing temporarily occurring excess heat, storing it temporarily and releasing it back into the room with a time delay.
In winter, the sand-lime brick wall stores the room heat during the day and returns it to the room air when the heating is lowered at night. In summer, the excess heat is stored during the day and released back to the outside at night via ventilation. Temperature peaks or overheating are thus avoided or reduced.
Bulk densities of 1.8 kg/dm³ or more are suitable for this purpose. The decisive factor is the size of the effective storage capacity C, see also Lexicon article ► Effective heat storage capacity.
Vapour diffusion: Depending on their bulk density , sand-lime brick walls have a water vapour diffusion resistance coefficient μ approx. 5 to 25 and thus an average vapour permeability. They are therefore considered a vapour-permeable wall construction and can absorb moisture from the room air to a certain extent and release it back into the room with a time delay. In order for them to have a moisture-regulating effect in this way, the interior plasters and paints must also be designed to be permeable to diffusion, see Important connection components.
Sound insulation: Due to its high bulk density , sand-lime brick is predestined for walls with increased sound insulation requirements. For more information, see also Lexicon article ► Sand-lime brick walls, sound insulation.
Fire protection: Sand-lime brick walls are non-combustible, single-shell fire walls made of sand-lime brick are possible from a thickness of 17.5 cm without plaster. For more information, see also Encyclopedia Articles► Non-load-bearing masonry partition walls, fire protection requirements and ► Interior fire wall, requirements.
Thermal insulation for interior walls: As a rule, there are no requirements for thermal insulation for interior walls. However, in individual cases there may be an obligation to provide proof according to EnEV, e.g. if an unheated basement is adjacent to a heated stairwell. Since sand-lime brick has a high thermal conductivity, an additional insulation layer on the "cold" side of the basement is recommended.
In addition, it can make sense to place chine stones with a significantly improved thermal insulation value as the lowest or top layer of stones for walls above or below unheated areas in order to improve the thermal separation between the floor slab or ceiling and wall.
Masonry dimensions: Despite the fact that most construction companies are equipped with cutting equipment for masonry blocks, it still makes sense to take the masonry dimensions into account as far as possible in the planning. These are regulated in DIN 4172 and are based on a grid of 12.5 cm (see ► Masonry dimensions). Based on the 12.5 cm grid, a surcharge of 1 to 3 cm must be taken into account for the floor height in the shell dimension for the production of the mortar bed including bitumen membrane before the first row of stones is laid. Economical shell construction heights can be, for example: 2.65 m/ 2.775 m/ 2.90 m.
Exposed masonry/visible surfaces indoors: Frost resistance usually does not play a role in exposed brickwork indoors.For visually subordinate areas (e.g. basements, industrial buildings), it is therefore possible in principle to use all common types of stone made of sand-lime brick unplastered and also untreated. For higher demands on the design, there are numerous sand-lime brick products that are suitable for exposed masonry or have been specially developed for it:
Exposed masonry is constructed in accordance with Eurocode 6. When planning exposed masonry of high visual quality, the architect also has the task of precisely planning the position of the joints. If necessary, a joint plan must be drawn up in order to precisely match the length of the wall and the location of lintels, door openings, etc. to the selected stone format or to fit it into a masonry bond.
There are no binding rules regarding the design of exposed masonry. Accordingly, precise agreements or a detailed tender in accordance with the requirements of DIN 18330 VOBC are important. The creation of sample surfaces can also be helpful, see also encyclopedia articles: ► Masonry Bonds and ► Masonry Dimensions.
Special components: A variety of additional products are offered as a supplement to the wall blocks.
Important for the creation of interior walls can be:
Ecology: Sand-lime bricks have a good ecological balance, they are produced only from the natural materials sand, lime and water. No chemical additives are added, and there are no environmentally harmful residues. The energy required during production is low.
The building material sand-lime brick is reused as an aggregate in the production of sand-lime bricks or in concrete components. It is also used in earthworks, roads and paths.
Legally binding nature of DIN "V" 106: Despite its character as a "pre-standard", DIN V 106 has been published in most German federal states via the respective list of technical building regulations, thus being introduced by the building authorities, and must therefore be observed by all parties involved in the planning and execution of structural facilities.
and approval: See encyclopedia article ► Sand-lime brick, application and approval
Association: Masonry may only be bricked in a bond, i.e. that the overlapping joints are offset from each other. Care must be taken to ensure sufficient overlap during construction, otherwise plaster cracks are favoured: The offset (over-binding dimension) must be at least 0.4 x H or 40 mm for masonry blocks whose height is 250 mm or smaller. For stones that are higher than 250 mm, at least 0.2 x H or 100 mm. See also► Masonry Associations.
Creating walls: For stone formats > 25kg, a relocation device is required. Before the first row of stones is placed, a horizontal seal against rising damp and/or for acoustic decoupling and a levelling layer of normal mortar with a thickness of 1 to 3 cm is applied to the ceiling or floor slab. This serves to compensate for unevenness, so that the first row can be created absolutely perpendicular and aligned.
Waiting times: Experience has shown that the majority of the regular changes in the shape of a shell take place in the first weeks and months. Accordingly, a waiting period before plastering is recommended to avoid cracks.
Frost and heat: If the heat is too strong, the stones should be wetted to prevent the mortar from being absorbed too quickly into the absorbent stone. In the same way, the masonry must be protected from frost and heavy moisture penetration. The construction of masonry with frozen building materials is not permitted. Masonry that is open at the top should be covered with slabs or tarpaulins.
Bearing joints: In the case of "normal" bricks, approx. 10 to 12 mm thick bearing joints made of normal mortar are applied with the mortar carriage or trowel. Flat stones and plan elements are mixed with thin-bed mortar about 2 mm thick. The application is carried out with thin-bed mortar slides or planks. After stiffening the mortar, overflowing mortar must be removed with the spatula.
Butt joints: The nominal dimension for butt joints for bricks without tongue and groove system is 10 mm. Sand-lime bricks with tongue and groove system are declared with -R. In these cases, butt joint mortar can usually be omitted. Exceptions are building boards of low thickness and often single-shell exposed wall walls. Here, the butt joint width is 2 mm, analogous to the bearing joint width. Additional mortar in the corner area of walls reduces the risk of cracks and forms a force-fit connection.
Exposed masonry: If the exposed masonry is not painted over the entire surface, facing bricks should only be obtained from one work in order to avoid undesirable colour differences. In addition, a wall or a section of wall should always be bricked up with only one delivery, because otherwise small color differences cannot be avoided here either.
KS facing bricks and KS bricks usually have only one edge-clean head and runner side due to their manufacture. The stones must be brought into the correct position by turning them correctly. In the case of increased requirements, e.g. exposed masonry on both sides, it must be assumed that a certain number of stones must be sorted out on the construction site. The larger the stone format, the more irregularities on the edges of the stones are noticeable.
Defects in the stones must be complained about upon delivery, but in any case before the bricking.
Sound bridges: Special attention must be paid to the avoidance of sound bridges during the execution, as these can significantly reduce the planned sound insulation of the partition wall. Particularly important here is
Note: The DIN 1053 series of masonry standards has been withdrawn with the exception of the revised DIN 1053-4 (prefabricated components). Its successors are the Eurocode standards of the DIN EN 1996 series. Although DIN 1053-1 (calculation and execution) has also been withdrawn by the Standards Institute, it is still valid until the end of 2015 via the building regulations in Germany. Their application is possible as an alternative to the regulations of Eurocode 6, but may not be mixed with them.
Note: DIN 4108-1 (Thermal insulation in building construction; Sizes and Units) has been withdrawn and replaced by DIN EN ISO 7345, 1996-01, Thermal Protection - Physical Quantities and Definitions.
DIN V 106, Pre-standard, Sand-lime bricks with special properties
DIN 1053-1, Masonry - Part 1: Calculation and execution
DIN 4103-1, Non-load-bearing internal partition walls - Part 1: Requirements and verifications
DIN 4108 Supplement 2, Thermal insulation and energy saving in buildings - Thermal bridges - Planning and execution examples
DIN 4108-2, Thermal insulation and energy saving in buildings - Part 2: Minimum requirements for thermal insulation
DIN 4109, sound insulation in building construction; Requirements and verifications
DIN 4109 Supplement 2, Sound insulation in building construction; Instructions for planning and execution; proposals for increased sound insulation; Recommendations for sound insulation in one's own living or working area
DIN 4109/A1, Sound insulation in building construction - requirements and verifications; Amendment A1
DIN 4172, Measurement Regulations in Building Construction
DIN EN 771-2, Specifications for Masonry Blocks, Part 2: Sand-lime Bricks
DIN EN 1996-1-1, Eurocode 6: Design and Construction of Masonry Structures - Part 1-1: General Rules for Reinforced and Unreinforced Masonry
DIN EN 1996-1-1/NA, National Annex - Nationally Determined Parameters - Eurocode 6: Design and Construction of Masonry Structures - Part 1-1: General Rules for Reinforced and Unreinforced Masonry
DIN EN 1996-1-2, Eurocode 6: Design and Construction of Masonry Structures - Part 1-2: General Rules - Structural Design for Fire
DIN EN 1996-1-2/NA, National Annex - Nationally Determined Parameters - Eurocode 6: Design and Construction of Masonry Structures - Part 1-2: General Rules - Structural Design for Fire
DIN EN 1996-2, Eurocode 6: Design and Construction of Masonry Structures - Part 2: Design, Selection of Building Materials and Execution of Masonry
DIN EN 1996-2/NA, National Annex - Nationally defined parameters - Eurocode 6: Design and construction of masonry structures - Part 2: Planning, selection of building materials and execution of masonry
DIN EN 1996-3, Eurocode 6: Design and construction of masonry structures - Part 3: Simplified calculation methods for unreinforced masonry structures
DIN EN 1996-3/NA, National Annex - Nationally Determined Parameters - Eurocode 6: Design and Construction of Masonry Structures - Part 3: Simplified Calculation Methods for Unreinforced Masonry
Structures EnEV - Energy Saving Ordinance for Buildings, Ordinance on Energy-Saving Thermal Insulation and Energy-Saving System Technology for Buildings
Source: bauwion
