Paving Jointing Sand & Sand Stabilising Solutions

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Paving Jointing Sand & Sand Stabilising Solutions - Online Shop

Paving ‘Jointing Sand Stabilisers’ are not normally the same thing as a “Paving Sealer” as sand stabilisers are more specifically designed to penetrate into the loose graded sand used to fill the joints, in order to bind the sand grains together between the blocks in the ‘flexibly’ laid pavement i.e. bedded in compacted sand and fill. The stabilised sand then greatly reduces weed growth and the sand grains being eroded by weathering. Where necessary, higher performance , specialist applied jointing sand stabilisers can be used to resist sand loss in commercial areas e.g. by Mechanical Street Cleaning machines, including vacuum sweeping and power washing operations.

Paving Jointing Sand Stabilisers are generally used to stabilise correctly graded sand in block paving joints that are a maximum of 5mm wide, excluding any chamfered arrises (note - these must never be filled with sand)

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Important note: Paving jointing sand stabilisers are not normally used with rigid paving using concrete or natural stone pavers, as this normally requires a jointing / pointing / grouting mortar to be used, especially where the joints in small format paving are designed to have a nominal 10mm width as this will vary due to the profiles of the stone. Here a pre-bagged GftK Paving Jointing Mortar should be selected according to the stone paving area’s use, exposure and requirements.

Paving Sealing products must be extremely low viscosity in order to ensure penetration of the surface and avoid delamination or peeling-off, and then to provide a sealed waterproof, or water-repellent and frost-resistant surface. The ‘surface coating’ types must also harden to a dense film that can increase the abrasion and wear resistance, plus they can possibly also improve the appearance of the surface. Paving Sealing products will have a very limited effect on the reduction of weed growth in the joints.

Paving Jointing Sand

Areas of concrete Block Paving that are almost 'Butt-Jointed' and/or have very narrow joints, typically less than 2mm, are not normally filled with a paving joint mortar or paving grouting product as such. This is basically because this is impractical to achieve, and any mortar will have very limited performance at these dimensions. The nature of this kind of paving generally means that this is also unnecessary, as it is laid for use on large areas over consolidated sand or stone, where it is designed to be a so-called 'flexible pavement' that is also free draining in support of ground water protection and flood protection etc. In addition to domestic driveways and the like which typically use 50mm thick coloured concrete blocks, one of the main applications of this type of commercial block paving today, usually with min. 80mm thick blocks, is for the many larger areas used for supermarket and other retail car parks as well as other vehicle hard standing and storage areas, where this is seen as a cost effective solution that is fast to install and with minimum maintenance - usually!

However, all of these block pavements as they are sometimes known, can have relatively short-term aesthetic issues because the narrow joints between the pavers tend to fill with whatever dirt and grime occurs on the surfacing, then over time, and often surprisingly quickly, the first wind blown seeds and weeds arrive. When the weeds are left they soon become unsightly, and with the arrival of invasive species such as bindweed, couch grass, celandine and ground elder, followed by larger fast growing shrubs such as buddleia and Japanese knotweed taking root the paving and its substructure become damaged. At some point this has to be stopped, usually by physical removal and chemical treatments, then with regular maintenance including weed removal and frequent applications of the chemical weed killers, In order to protect the environment and ground water, the use of these is now, and quite rightly in our opinion, being increasingly frowned upon.

Therefore right from the beginning these areas of block paving can employ a specialist Paving Jointing Sand and/or Paving Jointing Sand Stabiliser to fill these joints and prevent weed growth for as long as possible, though even the best of these will require replenishing every few years. The best we have seen is the very low dusting, polymer modified graded alluvial sand based, vdw VarioSand, developed by GftK and now widely used in Germany for this purpose. This advanced material will also prevent the jointing sand being washed out of the joints during normal rainfall and weathering. This is a special performance grade that is also suitable for sanding and stabilising such trafficked block paving surfaces, without an expensive toxic sealer.

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Paving Jointing Sand Stabilisers
‘Jointing Sand Stabilisers’ versus ‘Paving Surface Sealers’

Paving Jointing Sand Stabilising products have different design and formulation criteria. These need to be less penetrative but ‘tough and cohesive’ as well as more ‘flexible and elastic’ than the Paving Sealers, in order to adequately bind the sand particles together and keep them together in the joints, whilst also accommodating the natural flexing and movement of flexibly laid block pavements. The potential for weed growth is also considerably reduced as the flexible material tends to prevent seeds entering the joints and successfully germinating.

In summary – Always use a purpose designed and correctly formulated paving jointing sand stabilising product such as GftK’s ‘vdw 870’ for domestic applications. This is an acrylic resin based, water dispersed easy to use and safe jointing sand stabiliser. For more onerous conditions requiring even higher performance, such as high traffic commercial applications, the use of Resiblock 22 can be considered. This is a far more expensive and controlled application with severe site limitations and sanctions for use, because this product is based on aromatic polyurethane resin with isocyanate content and it is solvent dispersed.

These paving jointing sand stabilisers will both bind and anchor the sand in place, plus they will also provide a protective coating on the surface of the blocks to some extent; whereas paving sealing impregnations and surface coating sealers will effectively seal the surfaces, but will have no significant or durable effect on binding and stabilising the sand in the joints.

Jointing Sand Stabilisers for Sand Filled Joints in Block Paving

In principle all sand filled joints in block paving that are to be stabilised must be a maximum width of 5mm (normally nominal 1 – 5mm), with a minimum sand depth of 10mm, excluding any chamfered edges, as all sand from within any chamfered areas must be completely removed before applying the jointing sand stabiliser.

Paving Jointing Sand Stabilisers such as GftK’s ‘vdw 870’ will both bind the sand grains together and also to the edges of the concrete blocks, which helps to anchor the sand and the paving in place, plus this higher performance, purpose designed jointing sand stabilising products, will also significantly reduce any future weed growth etc.

GftK’s vdw 870

GftK’s vdw 870 can provide a very useful and cost-effective, easy to use, water dispersed and environmentally friendly solution for domestic applications, such as on patios and pathways and driveways with light vehicles (normal domestic cars and bikes etc.).

It is available to buy direct from our Online shop.

GftK Sand Stabilising Solution Products
GftK vdw VarioSand GftK vdw 870

For commercial applications with high performance requirements, these should always be undertaken by trained and experienced specialists that understand the important application requirements and related environmental considerations. We can provide detailed advice for your project, including the names of specialists in your area of the UK from our national network of professional paving and landscaping contractors.

You can call 01257 266 696 for FREE expert advice and assistance on your paving jointing sand stabilising project , or email us at technical@nccstreetscape.co.uk