With PROBAU, no questions are left unanswered when it comes to building and renovation.

PROBAU provides you not only with tailor-made building materials, but also with guidance and tips. In the list shown here, you will find the most important technical terms with explanations, to help you with all of your building projects.


ABC of Technical Terms

The ABC of building terms


Accumulating water
Groundwater, accumulating water or stratum water that applies hydrostatic pressure to the wall. This type of loading must be assumed to be present not only when sealing surfaces below groundwater level, but also in cohesive soils and/or on hillsides.

Anhydrite screeds
Anhydrite is used as the binder in this type of floor screed. Anhydrite screeds are constructed as floating or bonded screeds and must never be used in wet or damp rooms. As a rule, the surface of the screed must be ground or partially ground before further processing.

Adhesive contact area
A test criterion for tile adhesives. It describes the plastic deformation properties of an adhesive layer that has been applied with a notched spreader. The tile adhesive is “combed” on to the surface and a glass plate is laid onto it and loaded. The amount of adhesive on the contact surface between the glass plate and the adhesive is then measured. The adhesive contact area must be at least 65 % of the total surface area.

Annual heating requirement
Annual energy requirement per square metre of living/usable area. Measured in litres of heating oil or cubic metres of natural gas.


Blinding layer
A layer of sand or fine gravel used to even out the substrate before concreting takes place.

Binding agents or binders
Usually gypsum, lime or cement. These are used to bind the aggregates (sand or gravel) solidly together.

Bitumen is a mixture of various organic substances that is obtained when processing certain raw materials. Its viscous behaviour changes with temperature.

Bitumen emulsion
When bitumen is mixed intensively with hot water, the bitumen is distributed in droplet form throughout the water, creating a bitumen emulsion.

Bonded screed
This type of screed is bonded firmly to the substrate. The minimum screed thickness is approximately 20 mm.

Buttering-floating method
See “Combined method”.

Buttering method
A method used when laying materials in a thin bed of adhesive. The tile adhesive is applied to the back of the tiles and not onto the substrate on which the tiles are to be laid.


Cement screed
Cement is the binder that is responsible for hardening the material. Cement screeds harden hydraulically and take at least 28 days to harden completely. No flooring can be laid until drying is complete.

Combined method
(Also called “buttering-floating”.) Special method for laying tiles in thin-bed adhesive, e.g. in high-stress areas. The adhesive is applied to both the substrate and the back of the tiles.

Describes the thickness or thinness of the wet mortar. The consistency required depends on the type of application and is achieved by adding the specified quantity of water stated on the packaging.

Correction time
A test criterion for tile adhesives: The length of time during which the position of the tiles can be adjusted without adversely affecting the adhesive properties.

The process in which the mass of mortar or concrete is pressed together to make it more dense.

Cohesive soil
Cohesive soils are soils such as loam or clay that have plastic properties.

Carbon dioxide (“greenhouse gas”) is produced when fuels that contain carbon (coal, oil, natural gas or wood) are burned.

Cohesionless soil
Cohesionless soils include sand and gravel. They are soils that have no plastic characteristics.


Dry mortar mix
A dry mortar that has been mixed together in the factory and requires the addition of water before it is ready for use.

Drying time
Describes the length of time required for the material to completely dry out. This time must elapse before any subsequent works can be carried out.

Dry layer thickness
Describes the final thickness of the thick bitumen coating after it has completely dried through. The dry layer thickness must comply with the minimum required thickness for the applicable loading case and must never be thinner than this at any point.

DIN 4108
DIN (Deutsche Industrie Norm, or German Industry Standard) that stipulates the minimum requirements for thermal insulation in buildings, Parts 1 to 5.

DIN 18195
The German standard for the waterproofing of buildings. It describes the technical planning and implementation of waterproofing for buildings and covers the use of sealing materials for the various loading cases.

Drainage panels
Drainage panels are bonded onto the thick bitumen coating as a protective layer. The working space can then be backfilled.

Drying time
The time that must be allowed for the thick bitumen coating to dry completely before the working space can be backfilled.


Energy balance method
Comparison of heat lost and heat gained.

Energy Saving Ordinance (Energieeinsparverordnung EnEV)
Ordinance relating to energy-saving thermal protection and energy-saving plant and systems engineering in buildings.

Emulsion adhesive
Ready-to-use adhesives made of synthetic materials.
The material hardens in contact with air or by releasing water.

Expansion joints
See “Movement joints”.


Felt-float finishing
Describes the process of rubbing the surface of a partially set plaster using a felt float.

Finishing plasters
Plasters with specific grain size distributions, which allow different surface textures to be created. As a rule, they are are also available as through-coloured plasters.

Floor covering
The top surface layer of the floor that is directly used and walked on. It is also referred to as flooring.
The best known types of floor covering are parquet, laminate, tiles, carpets etc.

Floating method
Method used with thin-bed adhesives, whereby the tile adhesive is applied to the substrate.

The material, once hardened, is resistant to the effects of frost.

Refers to all of the layers and formwork above the load-bearing horizontal construction elements of a building.

Floating screed
This type of screed lies on one or several insulation layers and is not bonded firmly to the substrate. The minimum screed thickness is approximately 35 mm.


Means of the same kind, uniform. A mortar is homogenous if the material has been thoroughly mixed and can be evenly applied.

Hydraulically hardening thin-bed mortar
Dry mortar mix for fixing and laying ceramic tiles and slabs. Cement is used as the binder. Water must first be added before the mortar can set.


Loading case
When sealing surfaces that are in contact with the soil, different loading cases may apply: Soil moisture, non-accumulating seepage water, or accumulating seepage water.

Property of good pigments which do not fade when exposed to light.

Low-energy house
Low-energy houses have an outer wall with a U value of 0.3 or less.


The process of preparing the material. Dry mortars must be mixed with clean water to produce a lump-free paste before they can be applied. The best way to do this is using an agitator.

Movement joints
Joints that absorb the construction-related stresses between solid construction elements. These joints are sealed with permanently elastic material. If there are existing movement joints in the substrate, these should be continued right through to the surface of any cladding or surfacing materials laid on the substrate.

Masonry anchors
Rustproof wire anchors, used to connect masonry to neighbouring structures.

Mineral finishing plasters
As a rule, these are natural lime plasters that contain no synthetic additives.

Mineral plasters
Plastering mortar made of natural raw materials. The binder used in the mortar is lime, cement, a combination of the two, or gypsum.

Medium bed method
A method that has developed from the thick and thin bed methods. The adhesive is applied as a 5 to 15-mm-thick layer using a spreader with a large notch size. This allows slightly uneven surfaces to be regulated.

Mortar groups/Plastering-mortar groups
These describe the strength of the mortar. Masonry mortars are allocated to mortar groups and plastering mortars to plastering-mortar groups.

Maturing time
The length of time during which some materials must be left to mature between initial mixing and mixing again. Crack bridging
Describes the action of bridging existing or subsequently developed cracks in the substrate.


Non-pressing water
In this loading case, surface water and seepage water is present in dripping, liquid form. The water does not exert any hydrostatic pressure on the sealed surface.


When too much water is added to the dry mortar during mixing. This changes the material properties of the mortar.


Pressing in/Compacting
Describes the process of compacting the grout after it has been introduced into the joints.

Extremely fine, dry, coloured powder that is used to add colour to coloured finishing plaster, for example. These pigments are essentially light-fast and weather-resistant.

Pretreating the surface onto which the tiles are to be laid, by applying an emulsion or a different type of mortar in order to improve the bonding characteristics or reduce the absorbency of the substrate, for example, or to strengthen the surface, as required.

Primer/Bonding bridge
Pretreating the substrate by applying an emulsion or a slurry grout in order to improve the bonding characteristics or reduce the absorbency of the substrate, for example, or to strengthen the surface, as required. Primers are always applied using a brush, broad brush or roller.

Concrete and mortar must be treated after they have been poured/layed: depending on the ambient conditions, they need to be covered with plastic sheeting or kept moist for a certain length of time.

PS rigid foam panels
Technical description: Polystyrene rigid foam. Foamed plastic panels for acoustic and heat insulation. Also known as Styrofoam.

Processing time
The length of time during which the material can still be processed after it has been mixed. (See also working time).


Iron mesh or iron bars that are embedded in the concrete to minimise cracking in the concrete.

Roof ridge
Top edge of the roof, where the sloping roof surfaces meet.


A test criterion for tile adhesives. On vertical or steeply inclined surfaces, the distance through which the adhesive slips under the weight of the tile is measured in millimetres. If none of the tiles slip more than 0.5 mm, the test has been passed.

Soil moisture
If the loading case is described as “soil moisture”, the soil in this instance is very permeable, so that no dripping or liquid water affects the basement wall.

Slurry grouting
In general, sealing the surface with slurry grout. Here, it refers to the process of grouting the joints. Very fluid/soft mortar (slurry grout) is spread across the entire surface with a rubber squeegee to fill the joints.

Floor covering, usually made of cement, anhydrite, mastic asphalt or asphalt/bitumen, with an even, smooth surface. A distinction is made between “floating screed” and “bonded screed”.

Screed laid on a separating layer
This type of screed lies on a separating film and is not bonded firmly to the substrate. The minimum screed thickness is approximately 35 mm.

Describes the process of rubbing a partially set gypsum plaster with a steel float or trowel, using a little water if necessary.

Smoothing trowel
Steel or plastic trowel used when applying screeds or plastered surfaces and to achieve a smooth finish; also used for applying and/or smoothing the surface of finishing plasters.

Skin formation
A test criterion for tile adhesives regarding the time taken for the adhesive to start hardening after it has been applied. After this time, the adhesive capacity of the applied layer decreases. Once a skin starts to form on the surface, no further tiles may be laid. Fillet
Describes the rounded transition between walls and floors and at inside corners. Fillets are formed with a radius of between 4 and 6 cm using a mortar belonging to class MG II or III.

Scratch coat
A scratch coat is applied to give texture to or even out stone/tiled surfaces. It must be allowed to dry before further coverings are applied.

These are used in the production of bitumen products, to lower the processing temperatures, for example.

Silica sand
Sand made of minerals. Extracted from sandpits and river beds. Used as an aggregate for masonry, plaster and screed mortars.

Describes the shortening in length of a construction element during curing/hardening.

Describes the free-flowing property of a floor levelling compound. The material practically spreads itself across the surface. A rubber squeegee, a broom or a trowel is used to promote even distribution of the material. Lintel
A beam or horizontal support above an opening.


Thick coatings
Polymer-modified thick bitumen coatings are paste-like, trowel-applied compounds based on bitumen emulsions. They are used to seal the outside of walls against water and are applied to the side of the structure that is exposed to the water.

Thick bed method
The oldest method of laying tiles. Mortar is applied to each tile individually. The mortar layer is between 15 and 20 mm thick. Used for laying natural stone, for example.

Thin bed method
Now one of the most common methods used for laying tiles. A thin layer (between 2 and 6 mm thick) of adhesive is applied to the subsurface or to the back of the tiles. When using this method, the subsurfaces must be absolutely even.

Thickness of wet layer
The applied thickness of the thick bitumen coating on the structure to be sealed. The specified thickness of the wet layer must never be exceeded by more than 100 % at any point.


U value
Overall heat transmission coefficient. Quantifies the heat losses. It is expressed in watts per square metre per Kelvin, W/(m2xK), and indicates how much heat is lost through a square metre of wall if the temperature gradient through the wall is 1°C. The smaller the U value, the better the insulation.


Water for mixing
This specifies the amount of water that needs to be added to and mixed with the dry mortar to create the correct working consistency.

Working space
The working space is defined as the space between the outside of the basement wall and the earth. This working space is backfilled with soil once the thick bitumen coating has dried sufficiently.

Water vapour permeability
Describes how breathable a construction material is.

Working time
A product characteristic that refers to the length of time taken for the material to form a skin after it has been applied (see also processing time).

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