With the CEMEX Dense and Medium Dense Coursing Bricks, you can be assured of getting the best range of masonry solutionsdesigned to suit a wide range of building applications. QualityAssured manufacture ensures that CEMEX Dense and MediumDense Coursing Bricks are manufactured and tested inaccordance with the relevant sections of EN 771-3.

CEMEX UK Building Products LtdCEMEX House, Evreux Way, Rugby, Warwickshire CV21 2DT

DENSE AND MEDIUM DENSESOLID COURSING BRICKS

Material Datasheet

Product SpecificationsCOMPOSITION : Dense Aggregate and cement or blended medium dense

aggregate and cementDENSITY : Dense - Average 2000 kg/m3

Medium Dense - 1400 kg/m3

COMPRESSIVE STRENGTH : 7.4 N/mm2 minimum average for dense units7.4 N/mm2 minimum average for medium dense units

DRY WEIGHT : 2.8 kg approx for 100mm dense units2.0 kg approx for 100mm medium dense units

WATER ABSORPTION : 6-8% approx for dense units10-15% approx for medium dense units

MOISTURE MOVEMENT : Less than 0.5mm/m (dense)Less than 1.0mm/m (medium dense)

THERMAL CONDUCTIVITY : 1.29W/mK@3%m/c for dense units0.46W/mK@3%m/c for medium dense units

THERMAL RESISTANCE : 0.08m2 K/W@3%m/c for dense units0.22m2 K/W@3%m/c for medium dense units

Features and Benefits• Designed to be used for all types of construction above and below ground in conjunction with dense

aggregate and medium dense aggregate blocks• Can endure repeated cycles of attack from rain and frost• Minimises cutting of blocks onsite, in return reducing waste, cost and time

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w w w . c e m e x . c o . u k / r e a d y b l o c k

Length

Size available (±2mm)WidthHeight

ReadyBlock® Sales Office:North: 01236 822461South: 01298 22244

215 65 100

Delivery and StorageWhere requested packs can be delivered shrink wrapped.All packaging should be disposed of carefully inaccordance with local environmental requirements. If possible, delivered blocks should be stacked carefullyonto a prepared, clean, firm area to minimise soiling anddamage and in planned locations on the site. This reducesthe double-handling of the bricks.They should also beprotected from inclement weather and passing vehicles.Allow air to circulate through and around the stacks.These precautions will reduce the likelihood of limebloom, shrinkage and movement. Materials used inconjunction with concrete facing bricks should also be stored under protection.

Health and SafetyCare and attention should be given to the working area tominimise accidents. Further information may be found inHSE Construction Sheet 37-Handling Building Blocks.Safe lift/build heights will vary dependant upon the blocktype, thickness, etc. Weather conditions can also affect liftheights and restrictions may be needed due to forecastedwindy weather. Generally, lift heights should not exceed 6full block courses in a single working day. For cavity wallconstruction, the 2 leaves should be built up together and the difference in leaf height, at any stage duringconstruction, should generally not exceed 675mm. A separate material safety datasheet for precast concrete products is available from CEMEX.

BricklayingLaying, bedding and jointing: The first course ofbricks should be laid to a gauge rod or dry with timberjoint spacers to ensure accurate setting out. Too muchsuction should be overcome by increasing the workabilityof the mortar within the provisions of BS5628: Part 3.Avoid mixing mortar variations and use the mortarspecified by the designer. Perpendicular and bed jointsshould be fully filled. ‘Tipping’ and ‘furrowing’ will facilitatewater ingress, ‘furrowing’ can also reduce the compressivestrength of the walling. The specified joint profile shouldbe formed after allowing the mortar to harden slightly.Tooling is recommended to compact the joints, improveweather resistance and reduce shrinkage in the mortar.‘Bucket Handle’ is generally the most efficient joint profile.Recessed pointing is not recommended, particularly inareas of severe exposure. Keep bricks clean during layingand avoid smearing with mortar from the joints as this canbe difficult to remove. Joint finishing on a wet day requiresextreme care.

Bonding: Bonding patterns should be maintained atopenings. Any bonds that are broken can increase the risk of cracking.

Cutting and Chasing: Where cutting of blocks isrequired on-site, the use of a central cutting area shouldbe encouraged. On facing work, mechanical means shouldbe adopted to preserve a true arris. Wet cutting will help tomaintain the appearance of the bricks, but if this method isused the bricks should be hosed down immediately aftercutting and dried out prior to laying. Chases generallyshould not exceed one-third of the thickness of the wall invertical chasing and not deeper than one-sixth of the wallin horizontal chasing. Timber laths should be used asguides when using mechanical means. Goggles and dustmust be used when chasing concrete bricks.

Mortar: Above d.p.c and below parapets a 1:1:6 cement;lime; sand mortar or equivalent is suitable. Mixes shouldbe used within two hours of mixing, other than in the case of retarded mortars where the manufacturer’srecommendations should be observed, after two hours the mortar should be discarded.

Different types and strengths of mortar have differingproperties. In Class 3 sulphate conditions SRPC mortarshould be used. Mixing methods must ensure consistencyof colour and strength. Use only BS approved additives to improve workability. Mixing methods must ensureconsistency of colour and strength. Use gauge boxes or similar when missing.

Damp Proof Course: Damp Proof Course materialsmust be the correct width for the job, i.e; at least the width of the wall. On external walls a projection of 6mm is recommended at the external leaf. It is essential thatd.p.c’s are bedded above and below to avoid forming aslip plane under movement. A lap of at least 150mmshould be formed at joints in lengths of d.p.c.

Finished WorkProtection of finished work: All brick work should be protected from inclement weather and other on-sitepractices. Suitable protective sheeting should be placedover the block work and firmly tied into place. Care mustbe taken to protect the work from frost damage or rapiddrying out.

Movement Control: Unless movement control has been catered for at the design stage by discrete panelformations, it may be achieved through the provision of control joints and / or bed reinforcement. If controlprovisions are not indicated by the designers, it isadvisable to raise this point with them before workcommences. Where bed reinforcement is required as analternative or supplement to control joints to reduce therisk of cracking, it should be bedded in the horizontalmortar joints of the brick work.

Plastering: Areas of brickwork to be plastered orrendered should have raked joints to form a key for thespecial finish. For optimum adhesion a plater bondingcoat or similar should be used. Render should be appliedin accordance with BS5362. A spatterdash coat maybenecessary for good adhesion. If so, this should be onepart cement : 2-3 parts sand applied before the undercoat.

Rendering: On concrete bricks the render mix should be 1:1.5:4.5 or equivalent, using clean sand. In all cases of two - or three-coat rendering, the final coat should be a weaker mix than the undercoat, or same mix but thinner.

Painting: Smooth faced bricks are suitable for paintingwith alkali-resisting paints, especially plastic emulsions.Brickwork should be dry and free from dust, limebloom,grease and other detritus. Oil based paints should be avoided.

SustainabilityAt CEMEX our environment matters, and the thermal mass of our ReadyBlock® range not only could reduce the need for air-conditioning in the summer but could also reduce theconsumption of winter heating fuel by capturing solar gains.

FAQ’sQ.What is the U value (thermal performance)

of Course Bricks?

A. Individual bricks do not have U Values. A U Value is determined by the type and thickness of each of the elements used to construct the wall, includingairspaces. Extensive thermal insulation data is given in BRE Special Digest (SD4) ‘Masonry walls and beamand block floors’ available free of charge from CBA,alternatively, call our ReadyBlock® Helpline Tel: 0800 667 827.

Q.What is the life expectancy of aggregate brick work?

A. It has been shown over a period of many decades that if protected from aggressive chemical or abrasivesituations, concrete brick work does not deterioratewith time.

For more information contact our ReadyBlock® HelplineTel: 0800 667 827.

The information contained in this publication was accurate at the time of production, howeverCEMEX reserves the right to introduce modifications or changes to detail at any time, as part of apolicy of continuous improvement.

This paper is produced from pulp sourced from properly managed sustainable forests, iselemental chlorine free, uses up to 20% best white waste and is totally biodegradable.

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