Largely manufactured from recycled glass (e.g. windscreens) and mineral base materials such as sand and without the use of binding agents. The ingredients are melted into molten glass, which is cooled and crushed into a fine powder. The powdered glass is poured into molds and heated (below the melting point) in a "sintering" process that causes the particles to adhere to one another. Next, a small amount of finely ground carbon-black is added and the material is heated in a "cellulation" process. Here, the carbon reacts with oxygen, creating carbon dioxide, which creates the insulating bubbles in the (material). CO2 accounts for more than 99% of the gas in the cellular spaces.
Cellulose insulation is a material made from recycled newspaper. The paper is shredded and inorganic salts, such as boric acid, are added for resistance to fire, mould, insects and vermin. The insulation is installed either blown or damp-sprayed depending on application.
Wood fibre
The success of wood fibre insulation derives from an attractive environmental profile combined with a whole bag of functions including rigid insulation, sheathing and sarking for timber frames, roofs and flooring as well as flexible insulation for studs and rafters.
Wood of course is renewable, it sequesters carbon during its growth and product production is relatively free from pollution. The insulation value of wood fibre boards is not as dimensionally efficient as some of the orthodox petro-chemical materials - but it's no slouch either - typically coming in with a 'k value' range of between 0.038-0.043 W/mK depending on format.
Hemp
Hemp fibres are produced from hemp straw of the hemp plant. Most hemp is imported, but an increasing amount of home-grown crop is becoming available. Hemp grows up to a height of nearly 4 metres within a period of 100-120 days. Because the plants shade the soil, no chemical protection or toxic additives are required for hemp cultivation. The product is composed of, usually, 85% hemp fibre with the ballance made up of polyester binding and 3-5% soda added for fire proofing.
Straw
Straw is an agricultural by-product, the dry stalks of cereal plants, after the grain and chaff have been removed. Straw makes up about half of the yield of cereal crops such asbarley, oats, rice, rye and wheat.
Void former also called ‘anti-heave’ board is often a lightweight structural material made of continuous paper honeycomb or EPS polystyrene core developed to separate concrete slabs from reactive soil which can potentially exert damaging pressure on the structural foundations of a dwelling and to replace some of the volume of concrete (screed) in applications such as floors.
Void former can be supplied as a block, slab or bespoke shaped pieces to suit the application or project. Standard board sizes are 2400mm x 1200mm up to a depth of 1200mm. Depending of brand, void formers come in multiple name options, including:
Cordek Cellcore HX S,
Cellcore HX B,
Cellcore HX Plus,
Cellcore HG,
Filcor 20/45/70/90/100/120/140/160/190,
Dufaylite Residential & Commercial Clayboard,
Whiterock Heave Stopper,
Jablite Fillmaster,
Kore Void Former,
Max-frank Pecavoid® Plus,
Max-frank Pecavoid® RD,
Max-frank Pecavoid® C,
Max-frank Egcovoid®
TYPES OF VOID FORMERS
Main types of cast in void formers can be categorised as collapsible or compressible.
COLLAPSIBLE VOID FORMERS
Collapsible void formers such as Dufalite Clayboard, Whiterock Heave Stopper or Max-frank Egcovoid® Former are a foundation stabilisers made using recyclable honeycomb cardboard core set between lightweight twin fluted polypropylene facings designed to collapse, creating a void for the ground to heave into. Unlike compressible void formers, collapsible boards are filled with water after the design compressive strength of the concrete has been achieved. By doing so, the load-bearing capacity of the board is eliminated. When dry, the board is rigid and strong enough to support the weight of wet concrete and steel reinforcement without deflection or creep compression.
Water is introduced by 36mm hole diameter void pack pipes or via the connecting hoses of the board to the panel core once the concrete is set. The amount of water is approximately 15 to 20 liter/m² depending on panel thickness. The water has to be injected with low pressure and begin with about 20% of the amount of water and after 30 minutes continue with about 30%. This degrades the honeycomb centre leading to the creation of a void. Hence the name of the collapsing board comes from. The board naturally disappears to leave a permanent 100% void with no residual density to pass on heave stresses. It’s 30% slimmer than polystyrene alternatives.
For more information on collapsible void formers click here.
For information on how to install collapsible void formers click here.
Void pack pipe simply “switches off" its compressive strength, taking it from 30kN/m2 down to a nominal 3KN/m2. This ensures that, when the ground heaves, the board yields with no resistance. The space accommodates clay expansion without exerting undue pressure on the structure above.
The resulting void continues to accommodate natural soil shrinkage and expansion to prevent structural damage. This makes the board an unique product, with its central core designed to collapse under just 3KN/m² once water has been introduced. The resulting void continues to accommodate natural soil shrinkage and expansion.
Picture credit: max-frank.co.uk
COLLAPSIBLE VOID FORMER COLOUR CODE
Each company has its own colour code. They are labeled to easily find on site which grade goes in which area. While Dufaylite Clayboard top face is usually black and the bottom face white, Whiterock Heave Stopper comes colour coded: red (60mm), green (110mm) and white (160mm). Max-frank Egcovoid® Former has off-white colour and its edges must be sealed off using sealing and repair red tape to achieve water tightness.
COLLAPSIBLE VOID FORMER RESIDENTIAL AND COMMERCIAL GRADES
While residential grade is calculated and calibrated for concrete thickness up to 1000mm, commercial grade is used on concrete thicknesses from 1000mm up to 1940mm. Collapsible void formers such as Dufaylite are available in two standard strengths, KN30 (Residential Grade) and KN90 (Commercial Grade).
On the other hand, Whiterock Heave Stopper being an alternative void former to Dufaylite’s Clayboard, is available in just one maximum strength of 120kn/m2 (good to be used as a residential or commercial applications).
Max-frank void former has maximum permissible load for dry panels of 100 kN/m2.
COLLAPSIBLE VOID FORMER SIZES
Dufaylite Clayboard® is supplied in panels 2440mm long by 1000mm wide offering coverage of 2.44m2, Whiterock Heave Stopper and Max-frank Egcovoid® former are manufactured in size 2400mm x 1200mm and standard coverage 2.88m2.
To find out more on the differences between Cordek Cellore Hx s and Whiterock Heave Stopper click here.
To find out how to prevent heave when removing a tree click here.
Picture credit: directpiling.co.uk
COLLAPSIBLE VOID FORMER RESIDENTIAL GRADE PRODUCTS (up to 1000mm of concrete)
160mm DUFAYLITE RESIDENCIAL CLAYBOARD - 30kN/m² - concrete thickness up to 900mm
90mm/160mm/225mm CORDEK HX S UNDER SLAB GRADE 7/10 - 10kN/m² concrete thickness up to 220mm
90mm/160mm/225mm CORDEK HX S UNDER SLAB GRADE 9/13 - 13kN/m² concrete thickness up to 300mm
90mm/160mm/225mm CORDEK HX S UNDER SLAB GRADE 13/18 - 18kN/m² concrete thickness up to 460mm
90mm/160mm/225mm CORDEK HX S UNDER SLAB GRADE 18/24 - 24kN/m² concrete thickness up to 660mm
90mm/160mm/225mm CORDEK HX S UNDER SLAB GRADE 24/32 - 32kN/m² concrete thickness up to 900mm
90mm/160mm/225mm CORDEK HX S UNDER SLAB GRADE 32/42 - 42kN/m² concrete thickness up to 1220mm
100mm MAX-FRANK EGCOVOID® FORMER - 100kN/m2
MAX-FRANK PECAVOID® PLUS GRADE 13/19 -19kN/m2 concrete thickness up to 460mm
160mm WHITEROCK HEAVE STOPPER - 120kN/m2- concrete thickness up to 1940mm
COLLAPSIBLE VOID FORMER COMMERCIAL GRADE PRODUCTS (above 1000mm up to 1940mm of concrete)
CORDEK CELLCORE HG - 65 kN/m2 - concrete thickness up to 1940mm
90mm/160mm/225mm CORDEK HX S UNDER SLAB GRADE 32/42 - 42kN/m² concrete thickness up to 1220mm
DUFAYLITE COMMERCIAL CLAYBOARD - 90kn/m2 - concrete thickness up to 1940mm
WHITEROCK HEAVE STOPPER - 120kN/m2 - concrete thickness up to 1940mm
MAX-FRANK PECAVOID® RD RANGE GRADE 30/40 - concrete thickness up to 1140mm
MAX-FRANK PECAVOID® C RANGE GRADE 50/65 - concrete thickness up to 1940mm
JABLITE GROUND HEAVE PROTECTION BOARD GRADE 50/65 - concrete thickness up to 1940mm
COLLAPSIBLE VOID FORMERS THICKNESSES
The thickness of product required will be determined by the plasticity index, which is specified by the soil engineer. Varying thicknesses are available and we’ve shown estimated thicknesses, strengths and requirements below. Generally speaking there are available in 7 thicknesses:
For more information on collapsible void former thicknesses click here.
COMPRESSIBLE VOID FORMERS
Compressible void former unlike collapsible board is a combination product made of moulded EPS collection cellular legs with twin fluted polypropylene top made to protect foundations from the effect of ground heave. Due to its unique make up and excellent compression properties, this board is able to alleviate heavy pressure on concrete slabs and it stays underneath the poured concrete. Compressible void formers are often associated with brands like Cordek®, Jablite®, Max-frank® and Kore®.
When the ground heaves or expands it is this resistance from the concrete above that counteracts the upward force from below causing the product to progressively compress under a given load. Users of products which combat the effects of ground heave are already familiar with the benefits of using the compressible type, such as Cordek® Cellcore HX S or HX B, over the collapsible fill alternatives, made from paper honeycomb.
CELLCORE COMPRESSIBLE VOID FORMERS
Cellcore does not rely on material degradation for the system to become effective. Once the Cellcore panels are laid and the joints sealed, the surface is ready to receive the reinforcement and the concrete. Cellcore is unaffected by water so, in wet weather or when foundations are below the water table, work can continue without reducing its effectiveness.
To find out more about Cordek Cellcore Hx S and Hx Plus click here.
It is normal for this type of compressible void former to experience some compression during concrete pouring. This will normally be less then 10mm, dependent on the depth of the concrete and the method and rate of placement. Once the concrete has been poured, subsequent creep deflections will be minimal.
Cellcore compressible void former is more commonly used as a void former on construction sites because it is a low cost product and does not require the use of water and it is strong enough to actually walk on during placement of base spaces and reinforcement.
Legs are made of EPS with drainage holes in which enables the product to be used in areas either way you have a high water table or in a coastal environment. Those drainage slots are incorporated in the cellular base of each panel, to allow water trapped within the cells to escape as the product compresses.
The boards are manufactured in a range of thicknesses to meet the application – Beam, Slab or Insulated Slab.
Cordek® void former called Cellcore HX S Under Slab is the most known and used lightweight expanded polystyrene (EPS) block that can be used for concrete floor slabs to protect against the potential effects of ground heave by reducing the upward force transmitted to the structure from ground heave. Variations of the product are also available for use under floor slabs or alternatively where permanent formwork is required.
Cellular polystyrene sheets are available in a variety of depths 90mm | 160mm | 225mm and grades 7/10 | 9/13 | 13/18 | 18/24 | 24/32 | 32/42to suit most commonly encountered combinations of soil heave potential and concrete depth. Each grade has adequate strength to support a specified depth of wet concrete during construction and will collapse under its specified fail-load, limiting the upward pressures experienced during periods of clay heave.
Picture credit: directpiling.co.uk
JABLITE | MAX FRANK COMPRESSIBLE VOID FORMERS
Jablite® Ground Heave Protection is the second type of compressible void former that provides a stable platform to support a specified depth of wet concrete during construction.
Jablite® is followed by MAX FRANK and its Pecavoid®. This void former is manufactured from interlocking sections of expanded polystyrene.
Pecavoid® acts as a protective layer, between the soffit of the suspended foundation and the expanding clay soil and is designed to compress when ground heave takes place. MAX FRANK’s Pecavoid® RD Range (Reduced Depth) reduces depth grades for minimal excavation depths and is available in various grades for concrete depths from 100mm up to 1140mm. The C Range is used for deep concrete suspended foundations and can be manufactured to offer ground heave resistance for up to and beyond 2m head of concrete.
For information on how to cut polystyrene void formers clik here.
To find out what are the ground heave solutions click here.
To find out what are the heave symptoms click here.
HOW COMPRESSIBLE VOID FORMER WORK?
Each board is engineered to protect the foundations of buildings against the damage caused by the upward pressure of clay or ground heave in a given site and application situation. Compressible void formers work on principle grades that are specially calculated and calibrated for deformation of EPS under loading.
7/10 grade | 7 means 7 kN/m2 (safe load) | 10 means 10 kN/m2 (failure load)
9/13 grade | 9 means 9 kN/m2 (safe load) | 13 means 13 kN/m2 (failure load)
13/18 grade | 13 means 13 kN/m2 (safe load) | 18 means 18 kN/m2 (failure load)
24/32 grade | 24 means 24 kN/m2 (safe load) | 32 means 32 kN/m2 (failure load)
32/42 grade | 32 means 42 kN/m2 (safe load) | 42 means 42 kN/m2 (failure load)
Safe load – sometimes stated as the Normal Working Load (NWL) is the maximum safe force that a HX S material offers without fear of breaking.
Failure load - load at which the under slab will fail (permanent deformation).
Firstly the depth of the Cellcore HX S panel should be determined by the heave potential of the soil, as detailed in Table 1 below:
Table 1
Results of Soil Analysis
NHBC Category
Predicted Ground Movement
Depth 'Equivalent Void'
Plasticity Index
Shrinkage Category
Void Dimension (mm)
HX S
(mm)
10-20
Low
50
90
20-40
Medium
100
160
40-60
High
150
225
Secondly, the grade of the product is determined by the depth of the concrete to be cast on the Cellcore HX S, as detailed in Table 2 below:
Table 2
COMPRESSIBLE VOID FORMER PRODUCTS
CORDEK CELLCORE HX S
CORDEK CELLCORE HX B
CORDEK CELLCORE HX PLUS
CORDEK CELLCORE HG
JABLITE GROUND HEAVE PROTECTION BOARD
MAX-FRANK PECAVOID® PLUS
MAX-FRANK PECAVOID® RD Range
MAX-FRANK PECAVOID® C Range
COLLAPSIBLE VS COMPRESSIBLE VOID FORMERS
Compressible polystyrene void formers, have a much narrower safe load-fail load window and require the designer to significantly thicken the slab in order to resist the uplift, therefore, it has to be considerably thicker than paper honeycomb, so it’s automatically bulkier than collapsible void formers.
Collapsible void former is 30% smaller than the compressible polystyrene alternatives and requires significantly less ground work to prepare for foundations than the traditional beam and block method.
Polystyrene doesn’t biodegrade, so it’s like a landfill under foundations. As a result, it stays underneath the poured concrete and has a much greater chance of exerting force on foundations in the event of ground movement. However, Void Pack Pipe is required every 24m2 or for every isolated area. Cordek Cellcore HX Plus compressible slab can add an insulation benefit of up to R1.0 (W/mk thermal resistance) as standard, which helps to reduce energy consumption in residential buildings.
On the other hand, a collapsible void former can not be used with integral insulation and may introduce methane as the cardboard rots down.
While paper honeycomb is delivered direct to site in a weatherproof seal, eps compressible void former can be left uncovered on site. All in all, both types of void formers share one thing in common - they are manufactured from 100% recycled materials.
To find out how to insulatate under concrete floor click here
WHY DO I NEED A VOID FORMER FOR?
The structural damage caused by clay is well understood by engineers and designers here in the UK. The problem is particularly acute in the South East although climate change is having its effect on soils in other parts of the country. In the UK ground heave is primarily caused by the rehydration of clay or expansive shale soils, overburden recovery resulting from deep excavations, mining or trees and vegetation. Whilst clay is a major problem throughout the South East and in isolated pockets nationally, ground heave due to other causes may be encountered in any region.
The solution is to create a space between ground and foundation which soils can expand into. The Building Research Establishment estimates that in situations where there are trees on shrinkable clay soils, the surface movement can be up to 100mm. Clay heave can impose both lateral and vertical pressure foundations, often resulting in cracking and expensive structural damage. In latter years it has become standard practice to protect building foundations.
Shrink swell potential in UK
VOID FILLERS
Fill material such as Filcor, Jablite Fillmaster, Sundolitt or Kore are also called a void former. They are used for forming openings and voids within concrete structures and can be used for a wide range of applications including:
hard and soft landscaping,
motorways,
underpasses,
shopping centres,
foundations podium slabs,
swimming pools,
steps,
ramps,
road embankments,
slope stabilization,
temporary ramps,
rail platforms,
arch forming,
spiral staircase forming,
column forming,
complex shapes.
The formation of openings in concrete, either to reduce the weight of the structure or to provide access for services, calls for particular attention in the selection of the former material, positioning and subsequent withdrawal if required. In fact, the use of EPS as a structural lightweight fill has been accepted practice in the UK for over 30 years and globally for 50 years. As the EPS blocks are around 1% of the weight of traditional fill materials the net weight of the new road construction can be equal to the weight of soil removed. This alleviates pressures on existing poor ground.
FILCOR
Filcor is an exceptionally lightweight fill material, being around 1% of the weight of traditional fill materials. It is also used as a void former and a structural void former when additional compressive performance is required. In fact, Filcor EPS is a type of polystyrene block produced by the well known Cordek® company. Its close cell product has good structural properties and some inherent insulation properties too.
The low cost and lightweight of Filcor EPS makes it an ideal void former. Its use reduces the volume of concrete and therefore the weight of the structure.
Filcor works on a 1% compression figure. Basically we have all different grades from 20 to 190. Filcor 20 is the lightest grade and can take up to 800mm of concrete. In fact, Filcor 20 is light, weighing as little as 15kg per cubic meter. Next grade up is the Filcor 45 that can withstand max thickness of concrete of 1800mm. The thermal conductivity of Filcor is the rate at which heat energy passes through it and therefore the lower the value the better the material will insulate against heat loss. While there are 9 Filcor grades available, only Filcor 20 stands out from other grades. Why? It requires less raw materials to make-hence its low price.
The cost of manufacturing Filcor is considered linearly proportional to its density. Filcor 20 price is the lowest compared to the other Filcor grades: 40, 70, 90, 100, 120, 140, 160, 190. For this reason Filcor 20 would be the cheapest to buy. For instance Filcor 20 2400mm x 1200mm x 600mm size cost is £196.50 ex VAT. Standard concrete slab thickness in residential construction is 4 to 5 inches. This is why Filcor 20 and Filcor 45 are often considered as a standard grade.
Jablite Fillmaster is a geotechnical product used in fill applications where a lightweight material is required to reduce stresses on underlying soils or lateral pressures to retaining walls, abutments or foundations. It has been used on projects for road embankments, road widening, rail embankments, bridge abutments, retaining walls, flood and noise bunds, culverts and temporary access solutions. Where the application requires Fillmaster to withstand long term imposed loads the designer should take into account long term compressive creep. Fillmaster exhibits stable cyclic load behavior. Under moderate loads (less than 1% deformation) the material remains elastic under cyclic loading.
KORE VOID FORMER
Kore void former has been developed for use in major works such as motorways, underpasses, shopping centres, foundations and embankments. Its main task is to decrease the volume of concrete and reduce weight while increasing strength of concrete.
SUNDOLITT
Structural Fill is supplied as large blocks of EPS which are lightweight and easy to handle and install on site (2400mmx1200mm). The EPS is inert and non-toxic there is no requirement for PPE during normal handling of EPS. Structural Fill EPS is graded by its 10% compressive strength in accordance with BS EN 13163. Grades of Structural Fill EPS have been developed with a compressive strength up to 500 kPa. Available in compressive strengths from 70 to 500 kPa the product is designated by its strength – S70, S100, S150, S200, S250, S300, S400 and S500
SIDE CLAY PROTECTION BOARDS
Side protection board is used to prevent problems in foundations where the soil has a high clay content and is liable to heave. The product is designed to reduce lateral pressure on the side of trench foundations.
It is a low density coloured EPS for the purpose of easy identification. Heaveguard made by Cordek and Claylite from Kay-Metzeler come green in colour, Claymaster from Jablite come pink and Clayfill made by Stylite come yellow.
Those side protection boards do not compress significantly until loads exceed 20kN/m2. To produce 50% compression a load of 40kN/m2 is needed. It is not recommended for use under ground floor slabs or pile caps.
For more information how to install claymaster, heaveguard click here.
Picture credit: directpiling.co.uk
POLYSTYRENE VOID FORMER PRICE
Generally speaking thermal conductivity, density and brand itself are the basic parameters that affect void formers price. The price also depends on the EPS cost on the worldwide market. The price list of expanded polystyrene is constantly changing so the void former price as well. In general, the price list of Cordek Cellcore under slab HX S grades depends on standard factors such as domestic demand, availability of raw materials and fuel prices, including oil and inflation. As you would expect, most factories producing polystyrene use a lot of gas. The more they pay for gas the more we will pay for the final product. Moreover, the cost of transport was always included in the final product price. The raw materials needed to produce HX S under slab or HX B under beam are delivered to the factory, used for production, then once again delivered to the building site. As of 2024 you should expect to pay for commonly used 225mm Cordek Cellcore under slab (7/10 grade-max concrete depth 220mm) £117.64. On the other site its highest 24/32 (max concrete depth 900mm) grade will cost £138.29.
85mm Cordek Cellcore HX B Under Beam 24/32 is an expanded polystyrene block designed for use beneath reinforced concrete ground beams and pile caps to protect against the potential effects of ground heave.
Cellcore HX B Grade 24/32 is calculated and calibrated for concrete thickness up to 900mm (..
85mm HX B for Reinforced Concrete Ground Beams Grade 24-32 is a non-collapsible Cordek void former EPS board used beneath reinforced concrete ground beams and pile caps.
Cellcore HX B Grade 24-32 is fully tested, calculated and calibrated for concrete thickness up to 900mm to protect ground beams..
85mm thick Cellcore Under Beam HX B Board cut to 600mm widths
HX B Ground Beams Grade 24-32 for concrete thickness up to 900mm
Protects ground beams against the potential effects of ground heave
Used beneath reinforced concrete ground beams and pile caps
Special hollow construction expanded polystyrene (EPS) block
85mm x 600mm x 800mm Heaveguard Pile Collars are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against up..
90mm Cellcore HX S Under Slab Grade 24/32 is an EPS board designed for use beneath reinforced concrete floor slabs to protect against the potential effects of ground heave by reducing the upward force transmitted to the structure from ground heave.
HX S Grade 24/32 is calculated and calibrated fo..
90mm Cordek Cellcore HX S Under Slab EPS 24/32
HX S Grade 24/32 - Maximum Concrete Depth 900mm
Designed for use beneath reinforced concrete floor slabs
Protection against the potential effects of ground heave
Ground Heave Solutions - Cellcore HX S Under Slab EPS
30x30mm POLYBAR+ (Blue) Standard is a self-expanding sealing bar used for sealing construction joints, an revolutionary alternative to bentonite waterstops.
BLUE POLYBAR Plus when fully enclosed in a concrete structure will remain effective as waterstops, for the life of the structure in which is..
30x30mm POLYBAR+ (Blue) alternative to bentonite waterstops
Revolutionary product used for sealing construction joints
Resistant to water pressure with impressive expansion capacity
Great adhesion to well compacted, clean and dry concrete
Effective barrier to the passage of moisture from the ground
220mm x 600mm x 2400mm Cellcore HX B Under Beam 24-32 is a special hollow core construction EPS block used beneath reinforced concrete ground beams and pile caps.
Cordek Cellcore HX B Grade 24-32 is calculated and calibrated for concrete thickness up to 900mm to protect ground beams against the e..
220mm thick Cellcore Under Beam HX B Board cut to 600mm widths
HX B Ground Beams Grade 24-32 max. concrete depth up to 900mm
Protects ground beams against the potential effects of ground heave
Used beneath reinforced concrete ground beams and pile caps
Special hollow construction expanded polystyrene (EPS) block
Filcor 90 EPS Cordek (EPS) is a lightweight structural fill material used as a void former solution for forming openings and voids within concrete structures in Hard Landscaping, Soft Landscaping, Podium Slabs, Swimming Pools, Steps, ramps and shapes.
Cordek Filcor Grade 90 is calculated and cali..
Swimming Pools, Podium Slabs
Hard and Soft Landscaping, Steps, Ramps and Shapes
Heaveguard Pile Collars 220mm x 600mm x 800mm are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against u..
200mm Claymaster consists of low density expanded polystyrene which can be used when foundations need to be protected against ground heave and to prevent potential problems in foundations due to moisture movement in soils.
Claymaster Jablite is also called clay heave protection board, a moisture ..
200mm Jablite Claymaster Expanded Polystyrene Board (8' x 4')
Compressible-fill EPS used to protect foundations against lateral heave
Used on inside face of piled ground beams or deep trench fill foundations
155mm x 700mm x 700mm Cordek Heaveguard Pile Collars are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles ag..
155mm Cellcore HX B Under Beam EPS Block 32/42 is a ground beam protection board designed for use beneath reinforced concrete ground beams and pile caps to protect against the potential effects of ground heave.
HX B Under Beam for Concrete Piled Ground Beams Grade 32/42 is calculated and calibra..
155mm Cordek Cellcore HX B Under Beam EPS 32/42
155mm HX B Grade 32/42 - Max. Concrete Depth 1220mm
Provides protection against the potential effects of ground heave
Cordek HX B Under Beam (Grade 32-42) is a 155mm thick, 600mm wide and 2400mm long hollow core EPS block used beneath reinforced concrete ground beams and pile caps.
Cellcore HX B Grade 32-42 is fully tested, calculated and calibrated for concrete thickness up to 1220mm to protect ground beams aga..
155mm thick Cellcore Under Beam HX B Board cut to 600mm widths
HX B Ground Beams Grade 32-42 max. concrete depth up to 1220mm
Protects ground beams against the potential effects of ground heave
Used beneath reinforced concrete ground beams and pile caps
Special hollow construction expanded polystyrene (EPS) block
200mm Cellcore HG Grade 50/65 is a lightweight expanded polystyrene (EPS) insulation board designed for use in ground heave protection applications where the specification of the project mean that the standard Cellcore HX S Under Floor Slabs and Cellcore HX B Under Ground Beams products are not suit..
205mm Cellvent HX Grade 9/13, an expanded polystyrene (EPS) cellular void former, for use in limiting the pressure exerted on in-situ reinforced suspended concrete floors or piled ground beams.
Cellvent HX is available in a range of specifications and can be used in conjunction with gas membranes..
205mm Cordek Cellcore Cellvent HX Cellular EPS Void Former
Cellvent HX Grade 9/13 Maximum Concrete Depth 300mm
Reinforced ground floor slabs where subsidence is not expected
Used to alleviate the effects of ground heave and gas venting
Combined ground heave protection and passive gas venting system
Claymaster 300mm Pink Board is the original compressible fill expanded polystyrene material used to protect foundations against lateral heave, typically on the inside face of piled ground beams or deep trench fill foundations.
Shrinkable clays are soils containing a large proportion of mineral pa..
300mm Jablite Claymaster Expanded Polystyrene Board (8' x 4')
Compressible-fill EPS used to protect foundations against lateral heave
Used on inside face of piled ground beams or deep trench fill foundations
42mm Piling Foam (diameter 40mm) is a 2m long closed cell isofoam tube manufactured from polyethylene to prevent the concrete adhering to the reinforcing bars and for insulating heating and plumbing pipes.
ISO Foam has low thermal conductivity of 0.036W/mK at 0 °C therefore its reduces the loss o..
42mm Isofoam (diameter 40mm) 2000mm length
Piling and Debonding Foam Polyethylene Sleeve
Used also for insulating heating and plumbing pipes
Used to prevent the concrete adhering to the reinforcing bars
Sound absorbing properties, reducing pop and flow noises in pipes
700x700x220mm Cordek Heaveguard Pile Collars are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against up..
700x700x85mm Cordek Heaveguard Pile Collars are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against upl..
85mm Commercial Dufaylite Clayboard Ground Heave Collapsible Void Former is a unique sustainable, 100% recyclable maximum strength (90kn/m2) honeycomb board designed to solve ground movement issues and prevent structural damage caused to foundations by clay heave.
Dufaylite Commercial Clayboard V..
90mm Cellcore HX S Under Slab (32/42) is designed for use beneath reinforced concrete floor slabs to protect against the potential effects of ground heave by reducing the upward force transmitted to the structure from ground heave.
Cordek HX S Grade 32/42 is calculated and calibrated for concrete..
90mm Cordek Cellcore HX S Under Slab EPS 32/42
HX S Grade 32/42 - Maximum Concrete Depth 1220mm
Designed for use beneath reinforced concrete floor slabs
Protection against the potential effects of ground heave
Ground Heave Solutions - Cellcore HX S Under Slab EPS
HX B Under Beam 2400x600x85mm Grade 32-42, an unique polystyrene based board with hollow core and moulded legs used beneath reinforced concrete ground beams and pile caps.
Cellcore HX B Grade 32-42 is fully tested, calculated and calibrated for concrete thickness up to 1220mm to protect ground be..
85mm thick Cellcore Under Beam HX B Board cut to 600mm widths
HX B Ground Beams Grade 32-42 for concrete thickness up to 1220mm
Protects ground beams against the potential effects of ground heave
Used beneath reinforced concrete ground beams and pile caps
Special hollow construction expanded polystyrene (EPS) block
Cordek Cellcore HX S Under Slab 160mm (Grade 32/42) is designed for use beneath reinforced concrete floor slabs to protect against the potential effects of ground heave by reducing the upward force transmitted to the structure from ground heave.
The Cordek Cellcore HX S Under Slab EPS is a compre..
160mm Cordek Cellcore HX S Under Slab EPS 32/42
HX S Grade 32/42 - Maximum Concrete Depth 1220mm
Designed for use beneath reinforced concrete floor slabs
Protection against the potential effects of ground heave
Ground Heave Solutions - Cellcore HX S Under Slab EPS
Cellcore HX S Under Slab 32/42 is a 225mm thick EPS sheet designed for use beneath reinforced concrete floor slabs to protect against the potential effects of ground heave by reducing the upward force transmitted to the structure from ground heave.
Cordek Cellcore HX S Grade 32/42 is calculated a..
225mm Cordek Cellcore HX S Under Slab EPS 32/42
225mm HX S Grade 32/42 Max. Concrete Depth 1220mm
Ground Heave Solutions - Cellcore HX S Under Slab EPS
Designed for use beneath reinforced concrete floor slabs
Protection against the potential effects of ground heave
220mm thick Cordek Cellcore HX B Under Beam 32-42 is a non-collapsible 600mm wide void former board used beneath reinforced concrete ground beams and pile caps.
Cordek Cellcore HX B Grade 32-42 is calculated and calibrated for concrete thickness up to 1220mm to protect ground beams against the ef..
220mm thick Cellcore Under Beam HX B Board cut to 600mm widths
HX B Ground Beams Grade 32-42 max. concrete depth up to 1220mm
Protects ground beams against the potential effects of ground heave
Used beneath reinforced concrete ground beams and pile caps
Special hollow construction expanded polystyrene (EPS) block
Cordek Cellcore HX B Under Beam 32/42 is a 85mm thick EPS block designed for use beneath reinforced concrete ground beams and pile caps to protect against the potential effects of ground heave.
Cellcore HX B Grade 32/42 is calculated and calibrated for concrete thickness up to 1220mm (Tested to a..
85mm Cordek Cellcore HX B Under Beam EPS 32/42
85mm HX B Grade 32/42 - Max. Concrete Depth 1220mm
Cordek Cellcore HX B Under Beam 220mm (Foundation Protection Board) 32/42 is specially designed eps block for use beneath reinforced concrete ground beams and pile caps to protect against the potential effects of ground heave.
HX B Under Beam (Ground Heave Solution) Grade 32/42 is calculated and ..
Used beneath reinforced concrete ground beams and pile caps
220mm Cordek Cellcore HX B Under Beam EPS 32/42
Provides protection against the potential effects of ground heave
220mm HX B Grade 32/42 - Max. Concrete Depth 1220mm
Filcor 100 Cordek EPS (Expanded Polystyrene) is a lightweight structural fill material used as a void former solution for forming openings and voids within concrete structures.
Cordek Filcor Grade 100 is calculated and calibrated for concrete thickness up to 4000mm (has been tested to achieve the..
Swimming Pools, Podium Slabs
Hard and Soft Landscaping, Steps, Ramps and Shapes
50x5mm POLYBAR+ (Blue) Standard Version Concrete Joint Sealer is an alternative to bentonite waterstops that can be used for sealing construction joints.
BLUE POLYBAR Plus when fully enclosed in a concrete structure will remain effective as waterstops, for the life of the structure in which is in..
50x5mm POLYBAR+ (Blue) alternative to bentonite waterstops
Revolutionary product used for sealing construction joints
Resistant to water pressure with impressive expansion capacity
Great adhesion to well compacted, clean and dry concrete
Effective barrier to the passage of moisture from the ground
100x5mm POLYBAR+ (Blue) is a thermoplastic synthetic rubber based alternative to bentonite waterstops that can be used for sealing construction joints.
BLUE Polybar Plus when fully enclosed in a concrete structure will remain effective as waterstops, for the life of the structure in which is inco..
100x5mm POLYBAR+ (Blue) alternative to bentonite waterstops
Revolutionary product used for sealing construction joints
Resistant to water pressure with impressive expansion capacity
Great adhesion to well compacted, clean and dry concrete
Effective barrier to the passage of moisture from the ground
110mm Commercial Dufaylite Clayboard Ground Heave Collapsible Void Former is a maximum strength (90kn/m2) honeycomb board designed to solve ground movement issues and prevent structural damage caused to foundations by clay heave.
Dufaylite Commercial Clayboard Void Former 110mm is a BBA certified..
155x800x800mm Heaveguard Pile Collars are compressible low density Expanded Polystyrene (EPS) products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against upl..
205mm Cellvent HX Grade 13/18 is a cellular expanded polystyrene void former, used to limit the pressure exerted on in-situ reinforced suspended concrete floors or piled ground beams.
Cellvent HX is available in a range of specifications and can be used in conjunction with gas membranes, vent out..
205mm Cordek Cellcore Cellvent HX Cellular EPS Void Former
Cellvent HX Grade 13/18 Maximum Concrete Depth 460mm
Reinforced ground floor slabs where subsidence is not expected
Used to alleviate the effects of ground heave and gas venting
Combined ground heave protection and passive gas venting system
220mm x 800mm x 800mm Heaveguard Pile Collars are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against u..
300mm Cellcore HG Grade 30/40 Ground Heave Solution is a lightweight expanded polystyrene insulation board specially designed for use in ground heave protection applications where the specification of the project mean that the standard Cellcore Under Slab and Under Ground Beam products are not suita..
48mm (diameter 45mm) Debonding Foam called ISOFoam is a polyethylene based closed cell sleeve, used to debond the reinforcement from the concrete and for insulating heating and plumbing pipes.
ISO Foam has low thermal conductivity of 0.036W/mK at 0 °C therefore its reduces the loss of heat from d..
48mm Isofoam (diameter 45mm) 2000mm length
Piling and Debonding Foam Polyethylene Sleeve
Used also for insulating heating and plumbing pipes
Used to prevent the concrete adhering to the reinforcing bars
Sound absorbing properties, reducing pop and flow noises in pipes
85mm x 800mm x 800mm Heaveguard Pile Collars are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against up..
Filcor 120 Cordek EPS (Expanded Polystyrene) is a lightweight structural fill material used as a void former solution for forming openings and voids within concrete structures in Hard Landscaping, Soft Landscaping, Podium Slabs, Swimming Pools, Steps, ramps and shapes.
Cordek Filcor Grade 120 is ..
Swimming Pools, Podium Slabs
Hard and Soft Landscaping, Steps, Ramps and Shapes
160mm Dufaylite Clayboard Void Former Commercial Grade is a unique honeycomb clay heave protection board, used to solve ground movement issues and prevent structural damage caused to foundations by clay heave problems.
Dufaylite Commercial Clayboard Void Former 160mm is a BBA certified, lightweig..
205mm Cellvent HX Grade 18/24 is designed for use under suitably reinforced ground floor slabs where subsidence is not expected, combining the benefits of the Cellcore HX range with Ventform.
Cellvent HX is available in a range of specifications and can be used in conjunction with gas membranes, ..
205mm Cordek Cellcore Cellvent HX Cellular EPS Void Former
Cellvent HX Grade 18/24 Maximum Concrete Depth 660mm
Reinforced ground floor slabs where subsidence is not expected
Used to alleviate the effects of ground heave and gas venting
Combined ground heave protection and passive gas venting system
300mm Cellcore HG Grade 40/50 is a lightweight expanded polystyrene (EPS) insulation board designed for use in ground heave protection applications where the specification of the project mean that the standard Cellcore HX S Under Floor Slabs and Cellcore HX B Under Ground Beams products are not suit..
54mm ISO Piling and Debonding Foam is a 50mm diameter foam sleeve manufactured from polyethylene used to prevent the concrete adhering to the reinforcing bars and for insulating heating and plumbing pipes.
ISO Foam has low thermal conductivity of 0.036W/mK at 0 °C therefore its reduces the loss o..
54mm Isofoam (diameter 50mm) 2000mm length
Piling and Debonding Foam Polyethylene Sleeve
Used also for insulating heating and plumbing pipes
Used to prevent the concrete adhering to the reinforcing bars
Sound absorbing properties, reducing pop and flow noises in pipes
85mm x 900mm x 1200mm Heaveguard EPS Pile Collars are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles again..
Claymaster Pile Collar 220mm x 900mm x 1200mm is a compressible low density Expanded Polystyrene product, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against u..
Filcor 140 Cordek EPS (Expanded Polystyrene) is a lightweight structural fill material used as a void former solution for forming openings and voids within concrete structures in Hard Landscaping, Soft Landscaping, Podium Slabs, Swimming Pools, Steps, ramps and shapes.
Cordek Filcor Grade 140 is ..
Swimming Pools, Podium Slabs
Hard and Soft Landscaping, Steps, Ramps and Shapes
155mm x 900mm x 1200mm Heaveguard Pile Collars are compressible low density Expanded Polystyrene products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against ..
220x1200x1200mm Heaveguard Pile Collars are compressible low density Expanded Polystyrene (EPS) products, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against u..
270mm Cellcore Cellvent HX Grade 7/10 combines the benefits of the Cellcore HX range with Ventform to alleviate the effects of ground heave whilst also providing an excellent gas venting.
Cordek EPS Void Former Formwork Cellvent HX 270x1200x2400mm is designed for use under suitably reinforced gro..
270mm Cordek Cellcore Cellvent HX Cellular EPS Void Former
Cellvent HX Grade 7/10 Maximum Concrete Depth 220mm
Reinforced ground floor slabs where subsidence is not expected
Used to alleviate the effects of ground heave and gas venting
Combined ground heave protection and passive gas venting system
300mm Cellcore HG Grade 50/65 is a lightweight expanded polystyrene (EPS) insulation board designed for use in ground heave protection applications where the specification of the project mean that the standard Cellcore HX S Under Floor Slabs and Cellcore HX B Under Ground Beams products are not suit..
85x1200x1200mm Claymaster Pile Collar is a compressible low density Expanded Polystyrene (EPS) product, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard piles against upl..
Filcor 160 Cordek EPS (Expanded Polystyrene) is a lightweight structural fill material used as a void former solution for forming openings and voids within concrete structures in Hard Landscaping, Soft Landscaping, Podium Slabs, Swimming Pools, Steps, ramps and shapes.
Cordek Filcor Grade 160 is ..
Swimming Pools, Podium Slabs
Hard and Soft Landscaping, Steps, Ramps and Shapes
Pile Collar 1200x1200x155mm Claymaster (Heaveguard) is a compressible low density Expanded Polystyrene (EPS) product, used when foundations need to be protected against ground heave.
The Heaveguard (Claymaster) pile collar is an engineered material in green or pink color designed to safeguard pil..
270mm Cellvent HX Grade 9/13 is a robust void former made of Cellcore HX range with Ventform to alleviate the effects of ground heave whilst also providing an excellent gas venting.
Cordek EPS Void Former Formwork Cellvent HX 270x1200x2400mm is designed for use under suitably reinforced ground fl..
270mm Cordek Cellcore Cellvent HX Cellular EPS Void Former
Cellvent HX Grade 9/13 Maximum Concrete Depth 300mm
Reinforced ground floor slabs where subsidence is not expected
Used to alleviate the effects of ground heave and gas venting
Combined ground heave protection and passive gas venting system
Filcor 190 Cordek is a lightweight structural fill expanded polystyrene (EPS) used as a void former solution for forming openings and voids within concrete structures.
Cordek Filcor Grade 190 is calculated and calibrated for concrete thickness up to 7600mm (has been tested to achieve the specifie..
Swimming Pools, Podium Slabs
Hard and Soft Landscaping, Steps, Ramps and Shapes
270mm Cordek EPS Void Former Cellvent HX Grade 13/18 is used beneath reinforced concrete floor slabs to provide a combined ground heave protection and passive gas venting system.
Cordek EPS Void Former Formwork Cellvent HX 270x1200x2400mm is designed for use under suitably reinforced ground floor..
270mm Cordek Cellcore Cellvent HX Cellular EPS Void Former
Cellvent HX Grade 13/18 Maximum Concrete Depth 460mm
Reinforced ground floor slabs where subsidence is not expected
Used to alleviate the effects of ground heave and gas venting
Combined ground heave protection and passive gas venting system
270mm Cellvent HX Grade 18/24, consists of a moulded hexagonal EPS compressible base with Ventform to provide a combined ground heave protection and passive gas venting system.
Cordek EPS Void Former Formwork Cellvent HX 270x1200x2400mm is designed for use under suitably reinforced ground floor s..
270mm Cordek Cellcore Cellvent HX Cellular EPS Void Former
Cellvent HX Grade 18/24 Maximum Concrete Depth 660mm
Reinforced ground floor slabs where subsidence is not expected
Used to alleviate the effects of ground heave and gas venting
Combined ground heave protection and passive gas venting system