Paving Sealing Solutions

01257 266696

Paving Sealing Solutions - Online Shop

a. Paving Sealing

The sealing of any paved surfaces is usually done to either prevent/reduce staining, or to protect against frost damage, or both. The principle is that sealing the surfaces of porous stone and concrete block paving will prevent or greatly reduce the penetration and ingress of water and/or oils. This in turn will also increase the resistance of the surface to freeze-thaw attack and damage, such as surface delamination and scaling in winter – particularly when de-icing salts are used, as these greatly accelerate the freeze-thaw cycle and increase the damage significantly. As referenced several times before on this website, the most appropriate paving sealing solution is dependent on the specific paved surfaces and their exposure requirements; therefore these are further discussed and more specific advice is provided below on the best paving sealing options for your project, including our Paving Sealing Selection Guide.

NCC

Once you have determined your specific requirements, these products are available from our online shop. However, if you are still uncertain of the best paved surface sealing solution for your project, then please do not hesitate to call 01257 266696 or email us at technical@nccstreetscape.co.uk for FREE expert advice.

Important Note: It is important to remember that any new or existing areas of block paving or natural stone paving must always be thoroughly cleaned before they are sealed. - Any cement staining, dirt or grime, algae and other green growths, plus any other forms of surface staining must be removed before any type of paving surface sealer is applied. For assistance with cleaning and stain removal please visit our Paving Cleaners page.

b. Paving Sealing – for Concrete Block - Online Shop

NCC Block paving sealers can be the ideal way to help 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 oil, grease and other water-borne stains etc. Technically this is because the sealer makes the surface hydrophobic (repels water) and oleophobic (repels oils). As a result surface sealing can be very useful and should probably be even more widely recommended for protecting block paved domestic driveways, patios, terraces and many commercial areas, against vehicle oil leaks and many other stains and spillages, such as food and drink or gardening works etc.

Sealing the surface of concrete block paving to prevent or greatly reduce the penetration and ingress of water, will also therefore increase the resistance of the paved surface to freeze-thaw damage. This damage is not always recognised as such, as it usually becomes evident in Spring when our attention turns to outdoor surfaces once again. However, the damage occurred as water in the concrete block pores expanded as it froze, or more correctly, as it was repeatedly frozen and thawed, causing fine micro-cracks, then larger cracks and eventually crumbling and/or scaling-off from the surface is visible. These damaging effects are increased if de-icing salts are used in the area, as these greatly accelerate the chemical reactions that create this effect.

Modern block paving sealers from NCC Streetscape can be used from new when the paving is installed, or for their refurbishment, always after thorough cleaning and as outlined on the previous page. These sealers can be extremely useful in the upgrading and refurbishment of many different block paved areas on their own or in combination with NCC’s Paving Cleaners and Paving Jointing solutions that are also detailed on this website. The different sealers available include hydrophobic impregnations that penetrate deeply into the surface and repel water and oils, plus surface sealers that can also enhance the coloured surfaces with a matt or gloss finish (we normally recommend a matt finish for areas with any significant traffic).

Note: Paving Sealers are not necessarily the same thing as “Paving Jointing Sand Stabilisers”, as a “Paving Sealer” is specifically designed and developed to penetrate into 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, in order to bind the sand particles together and help to accommodate the natural flexing and movement of flexibly laid block paving (generally laid on compacted sand).

A correctly formulated jointing sand stabilising product is the ‘GftK vdw 870’ (acrylic vinyl copolymer based, water dispersed jointing sand stabiliser). For more information please refer to our Paving Jointing Sand Stabilisers page. 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.

c. Natural Stone Paving Sealers - Online Shop

NCC Sealing natural stone paving, in fact sealing natural stone of any kind, can be an emotive subject, as we have mentioned and discussed elsewhere on this website. NCC Streetscape generally share their views about preserving the beauty of natural stone, but in the traffic and severe exposure in modern public areas and commercial environments, this is increasingly only possible with the use of sealers, BUT selection of the right sealer is essential.

Additionally, there are many people who, possibly from their past bad experiences, are looking for a suitable sealer for their new or existing natural stone paving to protect the ‘natural’ stone surface from stains due to spillages e.g. from lawn mowing’s, other plants and leaves, oils and greases around barbeque areas, as well as against other food or drinks, including as always the dreaded red wine spills!

If you are looking to enhance the natural appearance and colour of natural stone, or even to provide a permanent ‘wet-look’ then this is not necessarily a straightforward exercise, as most glossy surface sealers you can use to provide the ‘wet-look’ will subsequently dull and abrade under any form of traffic – including just foot traffic. This would soon be visible and it would no longer look so attractive! Although gloss sealers can be replenished and refreshed, you might need to do this more often that you would like – at least annually we would suggest. A better and more durable alternative might be a paving sealer and colour enhancer with a more matt finish. (e.g. NCC Streetscape Natural Stone Sealer and Enhancer). This type of sealer can also be reapplied when eventually required.

Additionally, on any relatively porous natural stone such as sandstone and/or limestone that is being used for driveway paving, or for other commercial or public areas with vehicular access, then surface sealing is also highly recommended to prevent unsightly oil and grease contamination, cleaning costs and also the risk of frost damage as previously outlined.

It should be noted that there are some types of natural stone paving that is always relatively porous and where sealing of the natural stone is definitely advisable, or even necessary – i.e. for porous sandstone paving, limestone paving, and granite paving. If the paving owner /specifier / contractor wants to prevent staining where oil, food or other spillages can occur on this type of porous stone, then sealing with an effective surface impregnation and sealing solution is very highly recommended (e.g. GftK’s vdw 950 3-in-1 or NCCStreetscape Stone Sealer).

d. Natural Stone Sealing before Pointing / Grouting

Another recent development that has been made is to use GftK’s vdw 950 3-in-1, impregnating sealer is to use this to treat relatively porous natural stone paving once it is laid and the surface is cleaned, BEFORE application of the pointing mortar such as GftK’s vdw 850. This has proven to be very advantageous with stone paving that is known to be very, or variably, porous. Where it is known that technically the use of any cement based jointing will cause staining and cleaning problems as well as performance issues, and a brush-in compound is just not up to the job, one of the 2-component epoxy resin based vdw 800 series mortars from GftK is obviously ideal. However with such a highly porous or variable porosity stone, if applying the 2-part resin-based jointing compound to even the super-saturated (SSD) prewetted surface as usual, it is possible that in some of the most porous areas, the liquid resin binder could be partially absorbed, subsequently affecting the visual appearance of the stone. Contractors have discovered that by pre-sealing using vdw 950 3-in-1, this very effectively precludes the absorption of any resin binder and after the grouting is completed, a sealed and protected surface is left, with resistance to stains from spillages etc. There is also no risk of efflorescence through the stone as the impregnation and sealing is inside and within the capillaries of the stone itself.

GftK vdw 815 Application Important note: The costs of different types of paving sealing technologies and products can also appear to be hugely different. Firstly always try to not only compare the cost per litre, but the cost per metre applied, including the costs of their different application requirements, and most importantly any costs from their limitations e.g. polyurethane resin based sealers can give good results in terms of durability and service life, BUT they require absolutely dry conditions for their application and curing – otherwise they can be a nightmare. So, what are the additional costs of any possible weather delays, or expensive remedial works?). The final consideration again is the durability and service life required – are you happy to re-apply every year or do you want a much longer service life? The total costs can be more comparable after all the relevant considerations for each project are taken into account. In our experience today, the best options for natural stone sealers are either the hydrophobic impregnating sealers or the matt finish acrylic surface sealers that can now cost effectively meet most requirements.

Additional note: At NCC Streetscape we also have access to many more very specialised cleaning and sealing solutions and processes, but these are generally more restricted by cost or the necessary equipment required and so these are only used by experienced, trained professionals. If you think you need something more than the excellent products outlined on these pages please let us know and we can discuss your specific projects, please call 01257 266696 or email technical@nccstreetscape.co.uk

If you are uncertain of the best way to approach sealing your natural stone paving, then during normal office hours you can call 01257 266696 or email us at sales@nccstreetscape.co.uk at any time, for FREE expert advice on the best and most cost effective sealing solutions

Alternatively - If you already know what type of Paving Sealer you need – surface impregnation or surface sealer, please visit our Online Shop.

NCC
NCC
NCC
NCC
e. Paving Sealers – A Technical Summary & Selection Guide:

To provide more information on each of the alternative ‘Categories of Paving Sealer’ and the different ‘Types of Paving Sealer Materials’, we have summarized the main characteristics of the different Categories of Paving Sealers for both block paving and natural stone paving:

- Impregnating Paving Sealers – impregnating paving sealers are designed to penetrate completely and not to leave any significant film on the paved surface. Today these are usually based on Silane, Siloxane, Fluorosilicate or a blend of these materials dispersed in solvents or water and designed to penetrate and impregnate the paved surfaces forming a hydrophobic (water repellent) and oleophobic (oil repellent) finish.

- Surface Coating Paving Sealers – surface coating sealers for paved surfaces are designed to penetrate somewhat and / or to bond to the open texture of the mineral substrate that makes up the paving element. There is always some dry film thickness of the material that remains visible on the surface and it is this that can give a matt or gloss (wet look) finish to the surface. This film can also be tinted for products designed to ‘enhance’ the appearance. This type of paving surface sealers are usually based on Acrylic or Polyurethane resin materials, which again can be dispersed in suitable solvents, or increasingly with water due to the increasing H&S restrictions on solvent use.

These different categories of paving impregnation sealers and film-forming surface sealers each then also include a range of different types of materials technologies as indicated. The different characteristics and properties of these different paving sealers, together with their respective advantages and potential disadvantages for your paving sealing project can be further summarised as follows:

f. Paving Sealing Technologies
f.i.‘Impregnation’ Type Paving Sealers

Paving Impregnation sealers are usually designed around hydrophobic and oleophobic materials, and therefore based on Silanes, Siloxanes, Fluorosilicates or a combination of these materials. The range of products on the market varies including the likes of so-called water repellent Silicone Paving Sealers, which NCC Streetscape would never recommend and will not supply. They can impregnate only for a short depth and will last only a very short time, not even the summer in many cases, as they are broken down in sunlight and can be flushed out by water jetting (e.g. things like Thompsons Waterseal, or similar such equivalent private labelled Builders Merchants rubbish! - Please Do Not Use these inferior products unless you want a tatty looking job, are moving house, or you enjoy complaints and redoing the work!

Recommended impregnations for invisible paving sealing include water-based Fluorosilicate ‘Pore Strengtheners’ that also bond into the structure and increase the paved surface’s resistance to wear, in addition to reducing the permeability. Alternatively, there are solvent carried Silane and Siloxane based Paving Sealers, that will also give good long-term water repellence and therefore also provide good long-term resistance to water-borne staining, as well as frost or freeze-thaw / de-icing salt resistance. The solvent based products are always more efficient in colder weather and generally have higher penetration properties – but they are increasingly restricted and expensive because they are not so environmentally friendly.

The main advantage of impregnation products is that they penetrate fully into the paved surface and then work by lining the pores of the concrete or stone, repelling liquid water; but without changing the surface appearance, or preventing water vapour transmission. Efflorescence is greatly reduced or prevented on concrete block paving, the natural look is retained by stone surfaces, and these impregnating products can be used safely on all types of porous and sensitive natural stone. The paving impregnation sealer type products from NCC Streetscape will last for many years and then they can also easily be refreshed, by simple re-application at any time in the future, whenever this eventually becomes necessary.

In our experience and depending on the exposure, traffic and cleaning regimes this is likely to be for many years. This type of materials technology is also used throughout Europe and the USA for the protection of reinforced concrete bridge structures against water ingress and damage due to de-icing salts and frost damage. Several of these materials are therefore approved for this purpose by the different National Highways Agencies including the Highways Department in the UK.

The only disadvantages in terms of paving protection is probably that there is no additional ‘enhancement’ or ‘wet-look’ achieved and the protection is not always visible and easily monitored other than by performance – However, this is a very durable paving protection solution and is based on a totally different concept to the normal ‘visible sealer’ approach, by providing ‘invisible sealing and protection’ – These products are probably the best solution for those who do not really want to seal their natural stone or make a glossy (temporary) block driveway, but who do want to reduce staining and prevent frost damage to their paving.

Even the aforementioned ‘natural stone enthusiasts’ can frequently understand and agree with this approach, and so these impregnation sealer type products are increasingly considered acceptable, much better and increasingly preferred for stone protection in the modern environment. They will provide a high level of protection, maintaining the natural stone appearance, through effectively sealing the paved surfaces internally. Whilst certainly not cheap, their cost should always be considered in relation to their ‘invisible’ protection, extended service life and the ease of eventual reapplication, but only after many years, which seems reasonable to us.

f.ii. ‘Surface Coating’ Type Paving Sealers:

The two most prominent types of ‘surface coating’ paving sealers are Acrylic Resin or Polyurethane Resin based, both of which are available as both water dispersed and solvent dispersed products. In principle the solvent dispersed materials are a bit higher performance and used to give longer durability, but the newer technology in NCC Streetscape’s Paving Sealers using water dispersed materials, are now more than equal in performance and much more environmentally friendly to apply and in use.

f.ii.a Acrylic Paving Sealers

These are relatively cheap and easy to apply. A matt sheen or gloss ‘wet look’ (albeit temporary) for the surface is achieved with 2 or 3 coats (subject to porosity and consumption). The acrylic resin-based sealers leave a thin residual dry surface film that gradually reduces in service, through wear and UV light weathering, usually over a period of around 1-5 years, according to the paved areas level of use and exposure.

The Acrylic Paving Sealers all have the disadvantage that the surface film is not particularly tough to resist traffic and any highly used areas can soon wear and this can become visibly ‘different’. This is especially the case with gloss finish sealers. A wise man once said: “If you like your paving with a wet-look, then wet-it ...!” When the gloss surface is dulled by foot or vehicle traffic it can easily be refreshed by simply over-coating with a refresher coat. This visible wear effect is very much less apparent when a matt or satin finish sealer is used so these are the standard types that we recommend. It should also be stated that although the appearance may have been affected, the protective capability is largely retained, and water penetration and staining will continue to be greatly reduced. Also even though these acrylic sealers will all require re-application in 2 to 5 years depending on the traffic, this is also easy and relatively cheap to do with acrylic resin based paving sealers, so it is sometimes claimed as an advantage too! Our selected best options are the NCC Streetscape Stone Sealer and the NCC Streetscape Stone Sealer and Enhancer available in our Online shop.

Black Limestone Paving - In recent years there has been a bit of an explosion across the UK in the use of Black Limestone paving that is very attractive and works well with many garden designs and like all limestone surfaces is generally reliable and hard wearing. The only issue in fact is that the beautiful black (well very dark grey) paving, only stays black in the ground as the bedrock, and this colour only lasts a little longer than the paving installation and grouting period. Lots of contractors and stone dealers have had a lot of complaints, but it is not necessarily their fault. The customer is always right, the stone is strangely cheap (guess why?), and this phenomenon is well known, but only to those who regularly handle this stone that is imported from India and China predominantly. In order to give it the right descriptive name, this should probably be called ‘Black for 5 minutes, or when it is completely wet Limestone Paving, otherwise and when dry this is Light Grey Limestone Paving’.

As a result, there are many people around the country that are somewhat disappointed with their black limestone patio, in terms of its light grey colour specifically. In recent years there have been numerous products from paints to stains that have been produced to make the light grey limestone go ‘Back to Black’ the clue to one of those sold widely is in the name! However this product and other versions of this , or indeed the earlier paints and stains, all tended to give a gloss finish after using them to treat the exposed surfaces – Once more this looks and is great, until you walk over it a bit and the trafficked area is clearly visibly and you have a different sort of unsightly result – we think it looks worse than grey that is at least black every time it rains, just not when you are using your patio in the sunshine!

However, we have worked with some clever resin specialists and a couple of years ago they came up with a much better water dispersed, acrylic resin product that gives a deep dark but matt finish, which is also very resistant to foot traffic across it. Indeed, we did a popular Devon Pub’s Beer Garden Terraces a few weeks before their annual Music festival in May 2018 - and as you can see in the pictures, it has stood up to this and other pub garden type traffic, spillages and general abuse very well. This is the NCC Streetscape ‘Return to Black’ Stone Sealer that is available in our Online shop.

NCC
NCC
NCC
NCC
f.ii.b. Polyurethane Paving Sealers

Also called PU Sealers, these were traditionally the higher performance products designed for professional application for use in strictly dry conditions only, plus they came with a seriously higher price – Well somethings don’t change – if you are ever offered a ‘cheap’ PU Resin Paving Sealer – Forget it!

This PU technology provides a surface seal with long term durability, plus it can also provide substantial sand stabilisation on ‘flexibly’ laid concrete block paving. These are the best visible gloss or satin finish paving sealers for many commercial applications, but unfortunately good quality polyurethane resin based paving sealers are also correspondingly more expensive. However, this must be considered together with their increased performance and the best performing polyurethane resin, or ‘PU’ based products as they are also known, are generally agreed to be Resiblock 22, which is still solvent dispersed to ensure the PU's penetration into the concrete surfaces and mitigates any residual moisture, which in turn is because polyurethane sealers are extremely moisture sensitive and their limitations and application are critical. Not recommended for DIY applications, but we can happily discuss the requirements and possibilities with you, if this is of assistance, please call 01257 266696 or email technical@nccstreetscape.co.uk

g. Paving Sealing Product Pages
K-Seal Total Sealer NCC Natural Stone Sealer NCC Stone Sealer & Enhancer NCC ‘Return to Black’ Stone Sealer GftK vdw 950 3-in-1

Additional information and all the specific product performance details and characteristics are given in their respective PDS available on the respective product pages above. Please select the most suitable product for your project and then you can order online in our Online shop.

Alternatively, for more information and FREE advice and assistance on your paving sealing project requirements, please email us at technical@nccstreetscape.co.uk or you can call 01257 266696.

h. Paving Sealing Solutions – A Simple Summary

If you are not a professional paving contractors with experience of sealing paved surfaces, then when your evaluation and the simple water droplet test indicate that your paving would benefit from being sealed, there is no overall paving sealing solution. The nearest and best all round paving sealer is probably to use an impregnating type of invisible paving sealer, such as GftK’s ‘vdw 950 Stone Protect 3 in1’, which is available in our Online shop. This will probably give you the best chance of easily achieving good long term results without any problems.

However, this advanced impregnation type can sometimes be considered comparatively expensive for some types of paving such as concrete blocks in domestic applications. In these situations and with any other domestic paving with concrete and reconstituted stone or standard natural stone, the use of a solvent-free, water dispersed acrylic sealer will probably be the easiest and most effective, with lowest material costs in most domestic situations – These film forming sealers are also easy to refresh by simply cleaning and over-coating, whenever it visually becomes necessary in the future. E.g. K-Seal Total Sealer, or NCC Stone Sealer & Enhancer.

i. Paving Sealer Recommendations

As can be seen in the brief summary on this page, several different types of Paving Sealer have their place for different domestic and commercial pavement sealing applications and requirements, and this is true for both new paving and the refurbishment of existing paving. It is therefore important to be extremely clear about your specific paving project sealing requirements. Once these are fully considered and defined, you can evaluate the potential solutions using different material technologies and their respective advantages and disadvantages. We would suggest that in defining your requirements and criteria for your paving sealing project, that the following aspects are always included in your assessment:

j. Project Assessment Guide:
j.i. Checklist For my Paving Project I have / want / need:
  • Natural stone or concrete?
  • New or Existing / Refurbishment?
  • Surface conditions – Clean / Cleaning & Preparation required ...?
  • Surface permeability / porosity – Yes / No / …. Somewhere in the middle...What does this mean ….? How do I decide…? (A simple droplet test for porosity - see below)
  • Traffic anticipated – foot / car / other
  • Traffic frequency – occasional, regular, heavy
  • Durability – Life required
  • Durability – Ease of maintenance / repair
  • Visible Finish – None, Matt, Satin, Gloss (Wet-look)
  • Colour enhancing – No / Yes
  • Site / Area – Any adjacent surfaces / equipment / planting ...?
  • Weather – temperature range & rain possibilities
  • Environmental conditions – Any other exposure considerations for application ……? – and in service….?
j.ii. The Simple Water Droplet Test for Paving Porosity

There is a simple Surface Permeability / Porosity / Absorbency test that is also known as the Water Droplet Test. This was originally developed for use in the resin flooring industry, where it can be critically important for the resin primers to penetrate the concrete base slabs or the resin floor will not have sufficient adhesion. In preparation for seriously expensive resin flooring works, this pre-testing and substrate evaluation is carried out very precisely using a pipette and strictly measured, timed and controlled as shown in the examples below. Whilst paving sealing is not in the same league of costs or detailing as resin flooring, a variation of this test can easily be made on site to confirm the porosity or otherwise of the paving elements before sealing them.

The key information gained will be a good visual understanding of how well any water and/or water borne de-icing salts or stains, including the ubiquitous red wine, will also be able to penetrate and damage or disfigure your concrete blocks or natural stone. If water does penetrate easily and continue to be absorbed into the surface, then you would be well advised to consider the use of a paving sealing solution to protect your investment and maintain its good appearance!

Permeability / Absorbency Test (Water Droplet Testing) - The application of single droplets of water onto a concrete / natural stone surface, whilst observing any movement of the droplet, and monitoring the rate of absorbency into the substrate, will give a good indication of the surface density and permeability, and therefore if a paving sealer might be a good idea.

To correctly carry out the Water Droplet Testing, use a pipette or suitable dispenser and make groups of approximately 6 water droplets in different elements and areas of the paving, including on any areas that are discernibly different in appearance, texture or profile (to check consistency in results – or more importantly variations in permeability that are always possible and best found with water now, rather than later with oil or red wine etc.)

Place the droplets using a simple ‘dropper’, syringe or pipette (available from any chemist) type dispenser to suit, positioning them together within an area approximately 10cm x 10cm, be sure to always test at least the centre and the perimeter areas of your paving elements with different groups of droplets if necessary according to their size.

Example of Droplet Test on Dense Paving Surfaces

(i.e. smooth, hard and almost ‘shiny’ surfaces)

NCC

Water Droplets: Pipette Application
Note - No immediate absorption!

NCC

Water Droplets: 5 Mins Later
Note - No absorption evident!

If these were the surfaces of your concrete or stone paving, then a surface sealer is probably not required as water cannot easily penetrate and therefore the paving will be resistant too frost damage, plus as water cannot penetrate then it is most unlikely that the surfaces will be stained either.

Example of Droplet Test on Open-textured Paving Surfaces

(i.e. – surfaces that are ‘dull’ and not shiny in any areas, such as those that have been riven, sawn, or which have already been mechanically prepared e.g. by blastcleaning or grinding etc.).

NCC

Water Droplets: Pipette Application
Note – Absorption is immediately visibly evident

NCC

Water Droplets: 5 Mins Later
Note: - Absorption continues & diameter of penetration increases

These clearly porous concrete or natural stone paving elements are therefore highly likely to benefit from, or perhaps even need the application of a suitable sealer in order to prevent water penetration and future damage and / or being disfigured by unsightly and unhygienic staining.

So - A simple test and a good way to help you or your customers decide what makes sense for your paving projects. We hope that you find this additional information and advice helpful for your project.

For any more information on Paving Sealing for your specific project, please call 01257 266 696 for FREE expert advice and assistance.