Glossary

ADA stands for Americans with Disabilities Act. This accessibility legislation outlines, amongst other things, the regulations concerning steps and ramps in floors.  Our products with the ADA stamps fully comply with current legislation. See Accessibility Legislation.

Accessibility legislation forms an incredibly important component in the design and selection of expansion joints. Accessibility for the visually impaired and those with mobility issues is of paramount consideration. The vast majority of our floor joint systems fully comply with all known disability legislation requirements.

AquAtec is a waterproofing membrane system that encapsulates expansion joints in floors, walls and roofs. Read more about AquAtec here.

Built in profiles are expansion joint systems that are designed to be installed as floor, wall and ceiling finishes are being applied.

A centering plate is a component part of a number of our joints, for example the Megatec 340 or Megatec 350.  It is supported by frame fixed to the wall or floor and held in place by a centering mechanism.  It is associated with higher loadbearing joints.

The coëfficiënt of thermal expansion describes how the size of an object changes with a change in temperature. Specifically, it measures the fractional change in size per degree change in temperature at a constant pressure. Several types of coefficients have been developed: volumetric, area, and linear. For these forces we have created Thermal Expansion Joints to accomodate movement.

Column shortening is a form of structural distortion. Together with creep, drying shrinkage, thermal variation, seismic movement and wind loading, it is one on the principle causes of building movement. Like creep and shrinkage, the movement is non-cyclical.

See ‘Joint terms’

See ‘Settlement and Creep’

Elastatec is a multi-functional, UV-resistant, highly flexible repair tape for use in walls and roofs. Read more about this product here.

EPDM is the abbreviation of ethylene-propylene-diene monomer and is a member of a group of synthetic rubbers or elastomers. This material is used by Vexcolt in many of its rubber infills, for example in the Maxatec 100-A01 series, as well as in the Aquatec Waterproof membrane.  If a fire-rated product is required, we offer a Vamac rubber as an alternative.

See ‘Joint terms’

We have systems for both internal and external applications including:

Floor to floor systems
Floor to wall systems
Wall to wall systems
Corner wall systems
Wall to ceiling systems
Ceiling to ceiling systems
Roof to roof systems
Roof to wall systems
Parapet wall systems

Eurocodes are European standards and guidelines for the construction industry consisting of ten parts. These European standards are, like the EN standards, drawn up by scientists and engineers, users and practitioners from the industry. These standards describe which requirements a product must meet in any given environment. Read more about Eurocodes in our blog.

FEA stands for Finite Element Analysis and is a method by which the structural strength of a product is tested.  All our joints are subjected to FEAs to ensure they meet the loading capacities specified.

A fire compartment is a part of a building that can be regarded as an independent unit in the event of fire. The fire compartments must ensure that the fire and the smoke can be stopped for a period of at least 20 minutes, so that a safe escape route can be created. Vexcolt offer fire-resistant systems that provide either 2 or 4hour protection

FireFlex is a fire-barrier system developed to stop fire and smoke passing through structural expansion joints.  It can be used in floors walls and ceilings.

Fire resistance is a measure of the time a product will prevent the spread of fire or smoke.

Flexatec is a range of products including a multi-functional water-resistant expansion joints for floors and walls in stadiums, carparks, raised roads and other structures subject to vehicle load.

They are water resistant and can take heavy traffic loading.  Some examples are not suitable for foot traffic.

Floor finishes are materials that may be applied to a substrate to provide a wearing surface. These may be divided into five basic types:

• Resilient finishes which typically comprises carpet and vinyl flooring.
• Ceramic and natural (or synthetic) stone finishes including marble, granite, slate, terrazzo and other similar hard finishes.
• Polished and coating finishes which includes thin coatings <1.0mm thick, resin coatings >1mm thick, dry shake finishes and bare polished concrete.
• Wood floor finishes.
• Thick heavy-duty finishes such as mastic asphalt.

The normal way to eliminate random cracking of finishes is to divide floors (and walls) into panels or bays and to install a control joint at the perimeter of each bay.

These control joints flex and move in response to expansion and contraction of flooring panels and prevent cracking and delamination of finishes from the underlying substrate.

An insert, or infill, is the rubber central piece of an expansion joint.  Not all joints have this as some are made entirely of metal.  The infill can usually be removed after installation allowing for repairs to be made without disturbing the surrounding floor.  They are made of either EPDM, PVC Nitrile or Vamac depending on the product series and building requirements.

Isolatec is a waterproof contact voltage isolation membrane. It has been specially developed to isolate area where high levels of static discharge may affect people of equipment. It is used to ensure the isolation of passenger screen doors on rail platforms, finishes zones in electrified rail depots, power stations, electrical sub-stations and in other utilities including gas and oil installations.

Confusion exists in the terminology used to describe joints and for clarity the following terms should be used:

Expansion gaps – expansion gaps are physical gaps in the structure which run through roofs, ceilings, walls and floors effectively subdividing a building into a series os sub-structures each of which can move independently of the other.

Expansion joints are mechanical systems which are designed to span expansion gaps and accommodate the deflections anticipated at these locations.

Control gaps – control gaps are recesses or rebates left between floor and wall finishes to accommodate small localized deflections in finishes zones caused by drying shrinkage, thermal gain and loss and creep. Should such control gaps be omitted then random cracking of finishes is likely to occur.

Control joints are mechanical systems (or sealants) which are inserted into control gaps to accommodate the small deflections arising within finishes.

MaxAtec is the name of our range of metal expansion joints with coloured synthetic-rubber inserts.

MegAtec is the name of our range of all-metal expansion joints manufactured primarily from 6063 T6 aluminium and stainless steel.

The MicrAtec range is a series of movement control joints.  They are used to protect the floor finish from damage caused by drying shrinkage cracking, creep, and thermal expansion of the finishes zone.

Changes in humidity affect substrates such as concrete where low humidity levels cause concrete segments to contract and high humidity causes concrete to expand.

See ‘Joint Terms’

Retro-fit (sometimes called surface mount) profiles are expansion joint systems that are designed to be fitted after floor, wall and ceilings have been installed. These are often used in renovation projects.

RAL stands for ReichsAusschuss für Lieferbedingungen and is a coding system we use to define colours of seals, anodise finishes and coatings.

SeismAtec is a range of pan-based expansion joint systems specifically designed for use floors, walls and roofs of structures built in seismic zones.

Seismic zones or as they are properly termed Probabilistic Ground Motion Maps are generated showing the maximum earthquake horizontal ground motion for specific regions. These ground motion maps inform the calculation of maximum seismic impact upon a structure during an earthquake.

Settlement and creep are different and yet similar.

Settlement happens over time when the load applied by a structure to underlying substrates causes those substrates to compact. A classic example of this is seen in ground supported buildings built upon clay substrates (or other soils with a low California Bearing Ratio). As the clay dries out it shrinks, and the building experiences vertical deflection known as Settlement.

Creep is the deflection of a member of construction over time as a result of dead load, super dead load and imposed loading. In other words, if one considers a beam suspended between two points then over time the weight of that beam (plus any further loads applied to it) will cause the beam to sag in the middle.

Both settlement and creep play significant roles if defining expansion gap widths, anticipated deflections and the resultant specification of an appropriate expansion joint which matches these criteria.

Creep has the major role is defining the location of control joints.

A shrinkage crack (also called microcrack) is a thin crack typically caused by drying shrinkage in a slab, screed and mortar walls. Unless controlled these cracks can be carried through finishes causing damage to the wearing surface and dramatically reducing the effective working life of the floor or wall. Our MicrAtec ranges have been designed to ensure that these cracks occur in a predictable place and cause no harm to floor and wall finishes. Our technical sales team can help advise on the positioning of the Micratec movement control joints.

It is inevitable that the forces generated by drying shrinkage, thermal gain and loss and structural creep will have a significant impact upon the wall and floor finishes applied to a structure. The impact of these forces can result in the random cracking of finishes and the consequent compromise of both the integrity and longevity of finishes applied. It is important therefore to provide gaps between panels of finishes at regular intervals. These panels (or bays) should be formed by cutting into the substrate underlying finishes to a minimum depth of 25% of the substrate depth and then installing CONTROL JOINTS between finishes to protect them from surface damage.

The substrate normally refers to the material underlying the expansion joint and to which it is anchored. This can comprise a slab, high strength concrete screeds, structural metalwork or block, brick or mortar walls.

See ‘Retrofit profiles’

As temperatures rise and fall construction materials respond to these temperature variations by expanding when the temperature rises and contracting when temperatures fall. Thermal movement is one of the components of expansion and contraction which must be accommodated by both expansion joints and control joints. This category of joints can be classified as Thermal Expansion Joints. See also Coefficient of Thermal Expansion

Traffic may be broken down into five differing classifications as defined within current Eurocodes:

• Pedestrian traffic
• Traffic from small, hard-wheeled vehicles such as pallet trucks
• Traffic from forklift, trucks, cherry pickers and scissor lifts
• Traffic from passenger vehicles
• Traffic from road transport vehicles.

Our Technical Data Sheets (TDS) clearly outline the magnitudes of load that each system can withstand.

The frequency of a laden vehicle passing across a jointing system is as important as the load applied by that vehicle. The expansion joint must be able to withstand repeated loading rather than a single transit and therefore the traffic frequency that a system can withstand is vitally important factor in determining the lifespan of an expansion joint system

Our Technical Data Sheets (TDS) clearly outline the number of transits per day that each of the 5 load types can safely make across each joint system.

The TransAtec range of expansion joints have been expressly designed to provide smooth transit to pedestrian and heavily laden wheeled vehicles including pallet trucks, forklift trucks, cherry pickers, scissor lifts, passenger cars and road transport vehicles up to 63 tonnes laden weight.

UV Resistance is the ability of a material, often a polymer, to withstand the degradation that can be caused by exposure to ultraviolet light. If a polymer has low ultraviolet resistance, it could be subject to discolouration and/or premature or unintended failure because of deterioration.

Our products are UV-resistant, which means that they can be exposed to UV for a prolonged period of time without adverse effects.

Vamac is a specialized synthetic rubber which is normally used as seals in below ground applications. This heat and chemical resistant ethylene-acrylic poymer offers both high temperature resistance, low surface spread of flame and very low levels of toxic smoke when it burns. This means it is ideal for use in applications where the ease of escape during fire is restricted. Such applications include below-ground metro platforms and stations, basement levels in shopping centres and below ground connection tunnels between airport terminals.

An AquAtec waterproofing layer is often required beneath expansion joints (particularly in external locations and internal zones subject to wet wash-down) and this comprises a specialized EPDM membrane which is draped into the underlying expansion gap and resin bonded to the substrate either side of that gap.

We also have other products such as FlexAtec 1000 which has been designed for use where membranes are not suitable.

The design of a high-rise structure and its orientation and surrounding topography are key elements in determining the wind load signature of a building. Wind loading has implications particularly in terms of structural sway. It is therefore a significant factor which must be accounted for when defining deflections, expansion gap widths and specifying appropriate expansion joint solutions to accommodate deflections arising from wind loading.