Brick bricks for single-shell brick walls can meet all requirements for thermal insulation according to the latest Energy Saving Ordinance (EnEV) up to the passive house standard without additional insulation.
But brick walls are also very efficient in terms of sound insulation and fire protection. They 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 in disposal.
Image: Example "Lightweight flat brick with perlite filling" - Deutsche Poroton GmbH
Brick buildings ensure a healthy and natural indoor climate. Their high heat storage capacity has a temperature-balancing effect. Bricks have a natural capillary system that regulates humidity and are permeable to diffusion as an outer wall. For several years now, the industry has been developing bricks whose chambers are filled with insulation material to further improve the thermal and acoustic insulation values. Depending on the manufacturer, perlite, mineral fibres or softwood fibres are currently used as insulating filling material.
insulation planning: Due to the constantly growing requirements for thermal insulation, filled bricks have been developed. The chambers are filled with perlite or mineral fibre insulation materials. A 42.5 cm thick outer wall with λ=0.07 W/mK achieves a u-value of 0.16 W/m²K in this way.
Summer thermal insulation: Modern insulating bricks have a specific heat capacity of c = 950 to 1000 J/kgK and a heat storage capacity of S = 520 to 650 kJ/m³K for a 36.5 cm thick, monolithic outer wall. Single-shell brick outer walls thus provide good thermal insulation in summer, and there are no major differences between the individual types in this respect.
Sound insulation: The protection goals in terms of noise protection must be defined in advance between the planner and the building owner, as several sets of regulations exist side by side. Especially in residential buildings with several units, high requirements apply according to the state of the art, which in particular concern the transmission between the units. DIN 4109 regulates the absolute minimum standard, which is considered outdated today. Planners should use the increased values according to DIN 4109 Supplement 2 and VDI guideline 4100 as a basis. For buildings with several usage units, commercial bricks must be used, which have very good sound insulation properties in addition to good thermal insulation values. In terraced and semi-detached houses, the object bricks do not have to be used if the design of the communal wall prevents sound transmission between the units. Even if the common rooms are heavily exposed to noise from outside, it can make sense to use building bricks with high sound insulation properties. Due to the increasing requirements, the unclear legal situation and the complexity of the topic of sound insulation in terms of building physics, the preparation of a project-specific sound insulation report makes sense in many cases. But brick manufacturers also offer extensive services on this topic.
Partition walls: The integration of the partition walls between usage units into the outer wall, e.g. between office units or apartments or stairwell walls, is essential for compliance with the required sound insulation. As a result, sound transmission via the outer masonry can be interrupted at the transition between two usage units. The manufacturers offer various design details for this purpose.
Fire protection: Brick 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.
Masonry dimensions: Despite most construction companies being equipped with cutting equipment for bricks, it still makes sense to take the masonry dimensions into account as much as possible in the planning. These are regulated in DIN 4172 and are based on a grid of 12.5 cm (see ►Masonry dimensions in the lexicon). 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.
Vapor diffusion: Depending on their bulk density, brick walls have a water vapor diffusion resistance coefficient μ of approx. 5 to 10 and thus have a high vapor permeability. Any type of outer skin, such as exterior plaster, should also be designed to be diffusion-open so as not to block the transport of moisture to the outside.
Ecology: The starting materials for the production of bricks are clayey clays and water, i.e. natural materials without the addition of chemical additives. The energy used for production is relatively low, and disposal is unproblematic. Thus, bricks in their original form have a good ecological balance. However, the filling material may have to be taken into account in the assessment, which can lead to a deterioration of the ecological balance.
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.
Laying 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 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. A waiting period of 4 to 6 months is advisable.
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. Exposed window sills or masonry open at the top should be covered with plates or tarpaulins.
Bearing 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.
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)
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.
Note: DIN 4108-1 (Thermal insulation in building construction; Sizes and Units) has been withdrawn and replaced by DIN EN ISO 7345.
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 4172 Dimensions in building construction
DIN EN 771-1 Specifications for masonry blocks, Part 1: Masonry 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 defined parameters - Eurocode 6: Design and construction of masonry structures - Part 1-1: General rules for reinforced 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 defined 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 via the respective manufacturers
Source: bauwion
