Brick walls offer attractive properties, especially for high-quality basements , as they meet all requirements for thermal insulation, sound insulation and fire protection as a single-shell monolithic exterior wall.
External perimeter insulation is not necessary. Brick cellars are characterized by a healthy and natural indoor climate. Bricks are made of fired clay and porosed with sawdust additives, so that the original brick is a building material made of pure natural products, which is also harmless to dispose of.
Brick cellars have proven themselves in practice as durable and leak-proof basement structures. However, the prerequisite is careful planning and execution of the external waterproofing in accordance with DIN 18195 (see ► 105 | Waterproofing - Black Tub). Brick cellars are also advantageous in the construction process, as there is no need for time-consuming formwork, reinforcement and insulation compared to in-situ concrete walls. In addition, they offer smaller and cheaper wall structures with the same thermal insulation values, so that a brick cellar also achieves economic advantages.
Stability: The butt joints of basement brick walls can be interlocked, mortared or partially mortared. Sufficient measures must be taken to absorb the earth pressure. These can be vertically adjoining interior walls or pillars made of reinforced concrete , the exact determination is made by the structural engineer.
Thermal insulation: The requirements of the Energy Saving Ordinance also have an impact on basement rooms, because these are often included in the heated building volume. Brick walls are thinner than other wall systems with external insulation for the same wall thickness. Even highly thermally insulating bricks filled with insulation are available as basement bricks.
Fire protection: Masonry blocks made of bricks, including their fillings, are non-combustible and comply with building material class A1 according to DIN 4102-4. They therefore have excellent fire protection properties.
Vertical waterproofing: According to 18195-3, the subsoil for building waterproofing must meet high requirements in order for waterproofing to function safely in the long term. At the very least, all unevenness must be mortared or leveled. In the case of basement flat bricks with smooth surfaces, the waterproofing can be applied directly to the brick wall. In the case of brick masonry with plaster grooves, a thin or levelling plaster or a waterproofing slurry must be applied before the waterproofing is applied.
Masonry dimensions: Despite the fact that most construction companies are equipped with cutting equipment for bricks, it still makes sense to take the masonry dimensions into account in the planning as much as possible. These are regulated in DIN 4172 and are based on a grid of 12.5 cm (► 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 with 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.
Ecology: The starting materials for the production of bricks are clayey clays and water, i.e. purely natural materials without the addition of chemical additives. In contrast to concrete, the energy required for production is relatively low. The disposal of brick masonry is unproblematic. Thus, bricks in their original form have a good ecological balance. However, a final assessment can only be made in the case of filled bricks by taking into account the respective filling material.
Radon: Radon is a colourless, odourless and tasteless radioactive noble gas that occurs everywhere in nature, albeit locally in very different concentrations. According to a letter from the Bavarian State Agency for Environmental Protection, radon and the associated decay products are the second most common cause of lung cancer after smoking. A brick basement wall initially offers little protection against this, but the external waterproofing in the form of a black tub, which is required in any case for brick cellars, significantly reduces the entry of natural radon radiation from the ground.
walls: Before the first row of stones is placed, a horizontal seal against rising damp and a levelling layer of normal mortar with a thickness of 1 to 3 cm are applied to the floor slab. This serves to compensate for unevenness, so that the first row can be created absolutely perpendicular and aligned. . It must be led outwards under the first row of bricks and connected to the vertical waterproofing with sufficient overlap. The recommended material is the insertion of sanded bitumen cardboard, which is placed under the mortar layer under the first row of bricks. An overlap of at least 10 cm must also be made inwards, to which the vapour barrier to be applied to the base plate can later be connected.
Cutting: When cutting the bricks, care must be taken to ensure that the insulation of filled bricks remains in the chambers. However, individually empty chambers do not constitute a defect.
Bond: 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 that there is sufficient overlap during construction, otherwise plaster cracks will be favoured. The stones must always be bricked in a bond, i.e. with staggered butt joints. 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.
Openings: The reveals of openings should always be designed with the uncut sides of the individual stones so that the sealing tapes hold well in the long term during window installation. Alternatively, a smooth line of fine mortar can be applied to the soffits.
Rain, frost and heat: If the heat is too strong, the stones should be moistened 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. Exposed window sills or masonry open at the top should be covered with plates or tarpaulins.
Butt joints: Butt joints are not mortared in modern flat bricks, as they interlock via a tongue and groove system. The joints should therefore not be wider than 5 mm. (See ► Exterior bricks, tolerances )Storage joints
: Bricks are conventionally bricked in a mortar bed with a thickness of approx. 1 cm. However, the modern flat bricks of monolithic outer walls are mixed in the thin bed with a thickness of approx. 1 to 2 mm. This reduces the bearing joint to a minimum, which leads to an improvement in the insulating properties, but also to an increase in the permissible compressive stress.
Filling of the excavation pit: The backfilling of the work area can only be carried out once the additional loads such as the basement ceiling and ground floor walls set in the static calculation have been established. The supports for the ceiling above the brick cellar should also be removed before backfilling so that the load can take effect. Backfilling should be carried out with appropriate and not too large equipment and with the necessary care.
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.
DIN 1053-1, Masonry - Part 1: Calculation and execution
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 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 Masonry and unreinforced masonry
DIN EN 1996-1-1/NA/A1, National Annex - Nationally defined parameters - Eurocode 6: Design and construction of masonry structures - Part 1-1: General rules for reinforced and unreinforced masonry; Amendment A1
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 defined 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: Planning, 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
DIN EN 1996-3/NA/A1,National Annex - Nationally Determined Parameters - Eurocode 6: Design and Construction of Masonry Structures - Part 3: Simplified Calculation Methods for Unreinforced Masonry Structures; Amendment 1
DIN EN ISO 7345, Thermal insulation - Physical quantities and definitions
EnEV - Energy Saving Ordinance for Buildings, Ordinance on Energy-Saving Thermal Insulation and Energy-Saving System Technology for Buildings
Masonry Atlas, the Construction of Supporting Structure and Building Envelope, Günter Pfeifer, Rolf Ramcke, Joachim Achtziger, Konrad Zilch, 2001
►Technical information on brick systems, Poroton/ Wienerberger
Source: bauwion
