Paving Sealer Selection FAQS
Concrete Block Paving Sealers
Block Paving Sealers are not the same thing as “Paving Jointing Sand Stabilisers”, as a “Paving Sealer” is specifically designed and developed to penetrate the blocks and fill / seal them at a fine micro-pore / capillary level. Whereas, whilst a sand stabiliser may penetrate the larger capillaries of concrete blocks, the primary purpose is to flow into the joints and bind the jointing sand grains together and to the block edges. This effectively ‘stabilises’ the sand filled joints, which helps to prevent the jointing sand being eroded by weathering and cleaning operations. Paving Jointing Sand Stabilising products therefore need to be less penetrative, but tougher and more flexible and elastic than Paving Surface Sealers, to bind the sand particles together and help to accommodate the natural flexing and movement of flexibly laid block paving (so-called as they are generally laid on compacted sand, instead of a rigid concrete or cement mortar base or substructure).
For project requiring a paving joint stabiliser solution, then a correctly formulated jointing sand stabilising product is the ‘GftK vdw 870’ (acrylic vinyl copolymer based, water dispersed jointing sand stabiliser), or the combined sand and polymer based GftK vdw VarioSand. For more information on these different technologies, please refer to our Paving Jointing Sand Stabilisers page.
Paving Selection Overview - You can select the most appropriate paving sealer for your project using the extensive information in the pages of this website and if you are uncertain, then give our experts a call on 01257 266696.
The key decision factors for your selection are outlined in our Checklist and Testing page, where you will find a lot of detail to ensure you do not use the wrong product or get conned at a local merchant and go down the old and unfortunately well-known ‘Buy cheap, Buy twice’ route.
Then your key criteria for deciding on the right paving sealer, are always the type of paving and its use/exposure. The most widely requested types of paving and exposure are – Concrete Blocks e.g. as commonly used for driveways and parking areas. Or a Natural Stone paving e.g.’ for the optimum aesthetics on domestic patios and terraces. Therefore, on this page we give a little more information and advice for sealing each of these as follows below.
Concrete block paving sealers, however, can be the ideal solution to helping you to preserve and maintain the good appearance and function of modern block paving in many different areas. The application of a suitable block paving sealer can prevent or greatly reduce staining from oils, grease, and many other oil and/or water-borne stains etc. Technically this is because the application of the paving sealer makes the paved surfaces hydrophobic (meaning it repels water) and oleophobic (meaning it repels oils). As a result surface sealing solutions can be very useful and should probably be far more widely recommended and used for protecting block paved domestic driveways, patios, terraces, and many commercial areas, typically against vehicle oil leaks on trafficked areas, plus against many other stains and spillages, from foods and drinks to grass cuttings and other plant trimmings and residues from gardening works etc.
Sealing the surfaces of concrete block paving to prevent or at least greatly reduce the penetration and ingress of water, will also therefore directly and proportionately increase the resistance of the paved surface to frost and freeze-thaw damage, including de-icing salts exposure. This damage is not always recognised as frost and freeze-thaw damage as such, which is often because this damage usually becomes more visibly evident in Spring and Summer, when traffic increases, the area dries out thoroughly and our attention turns to looking at these outdoor surfaces once again. However, the damage occurred sometime before this, as water in the concrete pores expanded as it froze, or more correctly, as it was repeatedly frozen and thawed inside the blocks, causing fine micro-cracks, then more and larger cracks. Eventually, sometime later, these damaged areas are seen to be either crumbling and breaking down from the surface inwards or delaminating and scaling-off from the surface. These damaging effects are increased and will happen faster when any de-icing salts are used in the area, as these greatly accelerate the chemical reactions that create this effect.
Modern impregnating and surface sealing types of block paving sealers from NCC Streetscape can be used from new when the paving is installed, or much later for their refurbishment – though only and always after thorough cleaning outlined above and on the previous page. Therefore these sealers can be extremely useful in the upgrading and refurbishment of many different block paved areas on their own and/or in combination with NCC’s Paving Cleaners and the GftK Paving Jointing solutions that are also detailed on this website. The different types of paving sealers available for concrete paving blocks include the hydrophobic impregnations that penetrate deeply into the surface and line the pores to repel water and oils, plus the surface sealers that penetrate less deeply, but also form a protective film on the surface, which is why this type can also be used to enhance coloured concrete paving block surfaces i.e. the surface can be sealed and given a matt or gloss finish, we normally recommend a matt finish for areas with any significant traffic, as a gloss or so-called ‘wet-look’ finish can soon wear under any type of traffic – pedestrian as well as from any vehicles.
If you are uncertain of the best surface sealing or sand stabilising solution for your project, then please do not hesitate to call 01257 266696 or email technical@nccstreetscape.co.uk for FREE expert advice.
Natural Stone Paving Sealers
When looking to enhance the appearance and colour of their natural stone paving, people can often also want to provide a permanent ‘wet-look’ finish, which is understandable as after a summer shower the colours always seem heightened, more intense and with an attractive glossy wet-look, and many people would prefer to keep it this way. However, unfortunately this is not easy or straightforward, and therefore it is usually not advisable. This is because most glossy stone paving surface sealers that you can use to provide the ‘wet-look’, will subsequently dull and abrade very quickly under any form of traffic – including just with foot traffic. This would soon be very visible as a dull ‘pathway’ through the glossy surface, and it will no longer look so attractive – It is true that such gloss paving sealers can usually be refreshed quite easily with just another application on the surface (after cleaning), you might need to do this more often that you would like – at least annually we would suggest. A better and more durable alternative for most natural stone paved areas might be a paving sealer and colour enhancer with a more matt finish. (e.g. NCC Streetscape Natural Stone Sealer and Enhancer). This does not show or highlight any traffic use areas anywhere near as much as a gloss finish, and so this will provide a longer lasting and more attractive solution over the longer term. This type of sealer can also be reapplied easily when this is eventually required.
On any relatively porous natural stone paving units, such as the sandstones and limestones currently being used for domestic driveway paving, and for many other commercial and public areas with vehicular access, then surface sealing is now highly recommended both to prevent unsightly oil and grease contamination, plus to reduce cleaning costs, and to prevent frost damage. To prevent staining where vehicle or cooking oils, foodstuffs, drinks, and other spillages can occur, and/or to prevent frost damage on this type of porous stone, then sealing with an effective surface impregnation and sealing solution is very highly recommended (e.g. using GftK’s vdw 950 3-in-1, NCC Water-based Paving and Patio Sealer, NCC Stone Sealer, or NCC Stone Sealer & Enhancer).