How To Lay Cobblestones
What are Cobblestones?
Cobblestones present a timeless and beautiful paving option – they bring a tremendous amount of character to any space and with their superb genetic makeup they serve as a long-lasting paving solution.
Cobblestones are typically made from extremely dense stone materials such as granite, bluestone, quartzite and porphyry and are typically a superior option when it comes to grip strength.
There are many materials and designs to select when it comes to Cobblestones and this makes it relatively simple to create stunning outdoor spaces.
Modern cobblestones are created based on the century-old roads and walkways that are prominent in Europe.
What patterns do they come in?
With style options encompassing Chicago pattern, Herringbone Pattern, Brick Pattern, Straight Pattern – they also come in loose individual pieces allowing you to create your own unique design. There are many designs you can put together to turn your outdoor space into a stunning feature for your home.
Laying your Cobblestones
Generally, all cobblestones that are 20-30mm thick are to be laid on a cement base. It is important to consult your professional contractor to confirm the thickness of the concrete slab required as this may vary depending on the purpose of use and depending on the nature of use the installation methods can vary, this will change based upon your unique circumstances.
For driveway use, it is typically recommended to lay cobblestone pavers on a 120mm thick reinforced concrete slab.
All meshed back cobblestones are to have a tolerable thickness and size variation of +/-2mm. Cobblestones can vary by 3-4mm in size and/or thickness. Cobblestones that have a split finish can have more variation in size and thickness because of the split factor. This size tolerance needs to be considered during the installation process. When laying the Cobblestones the tradesmen will need to manually adjust some of the cobbles individually to the create the correct heights. During the installation process, it is also typical to remove the odd cobblestone from the batch that has been broken during transportation.
Employing the proper installation process gives the cobblestones a traditional appearance that is expected to be achieved as the finished product.
When installing cobblestones, it is important to use the proper adhesives, grouts, additives, sealers and pre-sealers to really bring out the best in the finished product and to have a “bulletproof installation”
Meshed back cobblestones are easier and quicker to install but you need to be cautious of what Glues and Grouts to use for this.
Epoxy Glue is the glue used to hold the cobblestones on the plastic mesh, it is also applied on the back of each cobble. The backing mesh is made out of plastic and has holes to allow the paving glue to go through the holes to create adhesion to the back of the cobblestone. This plastic mesh and the epoxy glue together cover at least 50% of the back of the cobblestone and allows for only another 50% of free space for the glue to stick to the back of the cobblestone. This is why it is very important to use a stronger bonding and fibre reinforced Non-Slump Adhesive.
Using stronger bonding glue is still not enough for a lifetime of adhesion. For example, when you have your car parked on the driveway and you try to turn the steering wheel of your car while your car is not moving: the rubber tires of your car will grab the cobble and will rotate the cobblestone which can cause the debonding.
To make even better adhesion you must apply thicker glue compare to your ordinary stone pavers. Recommended Notch Trowel size is 15mm. Once the 15mm glue is applied on the slab you will place the cobblestone sheets on top of the glue leaving another 10mm free space for the grout to go in, this means you have 5mm glue under the cobblestones and have 10mm glue all around the thickness of the cobblestones. This method allows Adhesion for all 5 sides of the cobble.
If you are installing cobblestones for an entertainment area that will only be exposed to foot traffic you can get away with a more ‘light’ installation method, however if you are planning for a driveway you will need what we like to call ‘heavy duty’ installation products as this area will take a lot more weight and vibrations than an area only exposed to foot traffic.
RECOMMENDED INSTALLATION PRODUCTS
For installation on footpath area, we recommend a Fibre Reinforced Non – Slump Adhesive like Ardex X18. If installing for a driveway we recommend the adhesive Ardex X18 mixed with Ardex E90 additive
(mixing ratio: 1 x 20kg bag of Ardex X18 + 2L of E90 + 4.5L of water)
Recommended grout isArdex WJ50 Sanded grout + Ardex Grout Booster.
(mixing ratio: 1 x Ardex WJ50 grout to be mixed with 2L Ardex Grout Booster + 2L water)
Ardex’ WJ50 is designed for gaps that are bigger than 3mm. This grout is a water-based, synthetic polymer grout additive. It creates improved adhesion strength, flexibility and abrasion resistance.
Grout Booster is added to assist in the flexibility of the grout and also helps to reduce efflorescence.
It is vital to make sure you pre-seal and top seal cobblestones.
You may use a pre-sealer like the Aqua Mix – Pro Block sealer, which is a water-based penetrating sealer used to pre-seal the stone. Pre-sealing cobblestones are vital when it comes to the cleaning of the grout.
Pro Block is an economical, natural look, breathable sealer. It is a water based penetrating sealer designed to resist staining caused by water-soluble minerals. It also helps resist efflorescence migration. ProBlock is not an adhesive bond breaker.
Pre-sealing assists you in sealing the stone just the right amount so that your installer can get off any excess grout or ‘grout haze’ without the use of stronger acidic types of cleaners which can be damage the integrity of the stones if not done with exceptional care.
The Top sealer then provides for the ‘final touch’ – you may use a sealer like Aqua Mix Sealers Choice gold – this will help protect your stone.
The Aqua Mix Sealers Choice Gold is a premium grade, high performance penetrating/impregnating stone, tile & grout sealer. It is a low VOC, water-based sealer formulated to provide maximum stain protection. This premium sealer also includes built-in Microban® – Cured Sealant and is Mould & Mildew Resistant, this sealer last up to 15 years.
All in all, cobblestones are an exceptional way to decorate your home, garden or driveway and bring a world of value to your doorsteps. With a multitude of options available you can find Cobblestone pavers in light colour or darks and materials such as Granite cobblestones, Porphyry Cobblestones, Quartz Cobblestones, Basalt Cobblestones and Limestone Cobblestones all being suitable choices with a unique beauty to be found in each type.
Armstone recommends you consult your professional installer to check your individual needs. Hopefully, this blog post helped you to understand the importance of the Installation method and the Recommended materials used to achieve timeless beauty that will last a lifetime. To determine the best product for your home and applications there are certain criteria to be met and we can assist with this should you need our help.
Feel free to give us a call or send us an email to chat more.
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