Weber Saint-Gobain - Official website of the company


This is the English section of the Technical Dictionary

Click on the first letter of the word in the alphabetic keypad below to jump to the relevant section of the list. Scroll up or down to find the reference or word  you require.

Abrasion resistance

The resistance of a hardened mortar surface to wear by mechanical action


A finely divided inorganic material that may be added to mortar in order to improve or achieve special properties

Adhesion failure

Failure occurring at the interface between mortar and substrate or associated material. The value equals the adhesive strength

Adhesion strength (bond strength)

The maximum adhesion strength of a mortar applied onto a substrate, which can be determined by shear or tensile strength test


Organic or inorganic material added in small quantity to modify the properties of the mortar in the fresh and/or hardened state


Granular material that does not contribute to the hardening reaction of the mortar

Air content

The quantity of air included in a mortar


Capacity of a mortar to absorb water not under applied pressure. There is no relation between porosity and capillarity

Cementitious adhesive

A mixture of hydraulic binder(s), aggregates, polymeric agents and other organic additives used to bond materials

Cohesion failure

Failure occurring within the mortar layer (where the strength of the mortar is lower than that of the substrate), or failure occurring in the substrate (where the strength of the mortar is higher than that of the substrate)


Process of manual or mechanical treatment of fresh mortar which increases its density

Compressive strength

Maximum value of a mortar failure determined by exerting a force in compression at two opposite points


The fluidity of a fresh mortar

Correction time (adjustability)

The maximum time interval during which adjustment is possible without significant loss of final strength.(eg. correction of bricks or tiles after application of the mortar)


Capacity of a hardened mortar to be deformed by stresses without destroying its structure. This characteristic can be evaluated by the modulus of elasticity which is measured in dynamic or static terms

Dispersion adhesive

A polymer based adhesive used for bonding materials


The mortar resistance to chemical, mechanical and climatic conditions which comprise its effective life


Crystallization of salts on the surface of a mortar

Flexural strength

Maximum value of a mortar failure determined by exerting a force in flexure at three points.(EN 1015-11 Masonry mortars) (EN 13888 Grouts for tiles)

Flowing screed

Screed made with self-leveling properties of a flooring mortar

Fresh mortar

<xml> </xml><xml> </xml> A mortar completely mixed and ready to use

Hard aggregate

Aggregate with high abrasion resistance.




Resistance of a mortar to penetration of water, under a certain pressure.



Maturing time

The interval between the time when a mortar is mixed and the time when it is ready to use.



Mechanical fixing devices

Devices for mechanically securing thermal insulation boards to the substrate. (e.g. rails or anchors).

Monolithic application

Application of a new layer of mortar directly onto the preceding one before the latter has finished setting.


A mix of one or more inorganic or organic binders, aggregates, fillers, additives and/or admixtures.



Open time

The maximum time interval for finishing after application of a mortar.(EN 1346 Tile adhesives)(EN 12189 Concrete repair mortars)



Polymer based coating

A colored polymer-based dispersion mortar for protection and decoration of vertical surfaces.




Ratio between the volume of pores within the mortar and the total volume.



Pot-life (working time)

Period of time during which, after mixing, a mortar remains suitable for use


Wires, meshes or fibres added to mortars or material incorporated within a render or system to improve its mechanical strength.



Repair mortar

A designed mortar for repair or replacement of defective concrete. It can be structural (contributing to the strength of the construction) or non-structural.




Layer of mortar laid in the foll situation- directly onto a base, bonded or unbonded or onto an intermediate layer or insulation layer to produce a defined level, to carry the final flooring to provide a wearing surface

Screed mortar

A mortar with which to carry out floor screeding.




The capacity of a fresh mortar to spread out naturally to form a flat surface.




The capacity of a liquid fresh mortar to form a smooth surface by itself

Setting time

The time after which, the mortar begins to harden.  After this time the mortar is normally stable in the presence of water.



Shear strength

Strength determined by a force applied parallel to the mortar surface

Shelf life

The time of storage under stated conditions during which a mortar may be expected to retain its intended working properties.




Volume reduction of an unrestrained mortar du-ring hardening.




Capacity of a floor wearing surface to provide friction, to resist slipping by walking foot or wheeled traffic.




The exposed horizontal undersurface of a part of a building


The immediate surface to which the mortar is to be applied. In the case of a coating to be applied to an existing render, the render would be the coating's substrate.




Admixture which, without affecting the consistency, permits a high reduction in the water content of a mortar, or which, without affecting the water content, increases the flow or which produces both effects simultaneously.




Material used to support the render/plaster so that it is largely independent of the substrate.



Surface hardness

The resistance of the surface of a hardened mortar, to indentation by a loaded steel ball.



Tensile strength

Resistance of a mortar surface, to resist a tensile force, applied perpendicular to the mortar surface.



Thermal conductivity

The value (l ) of a mortar in the dry state. The l-value is related to the density of the hardened mortar.



Thermal insulation material

Material which is intended to reduce heat transfer and which derives its insulation properties from its chemical nature and/or its physical structure.



Thin layer masonry mortar

A designed masonry mortar for joints between 1 mm and 3 mm thick


The change of consistency of a fresh mortar when energy is applied as for example by stirring or shaking.



Transverse deformation

Deflection recorded at the centre of a mortar, when a beam is subjected to three point loading.




The lower coat (or coats) of a system.



Undercoat mortar

The lower coat(s) of a rendering/plastering multi-coat system. It is normally covered with a finish coat.




Vermiculite Insulation material which results from expanding or exfoliating natural mica by heating.



Water retentivity

The ability of a fresh hydraulic mortar to retain its mixing water when exposed to substrate suction.



Waterproofing mortar

A designed mortar which prevents water penetration in a substrate, under a stated pressure.




The sum of the application properties of a mortar which give its ease of use.