Guidance
Product Guide Manufactured and Natural Stone Paving
Choosing to have a new patio or paved area installed is a long-term investment and needs careful planning. All Castacrete paving products need correct installation, protection and maintenance to help retain their natural character and beauty and the long-term integrity of the area.
The following is a guide only, which is applicable to both manufactured and natural stone paving. We would recommend you seek advice from a professional contractor.
Choosing your paving
Be sure that the product you have chosen is suitable for the project you are planning before ordering and more importantly before laying of the paving has commenced.
Things to consider when ordering your paving
Check quantities required and then check again. Order all materials to complete your project at the same time. To avoid delays to your project once it is underway, do not start work until you are sure all materials you require are with your supplier. NB: All sizing is nominal sizes (imperial sizes where quoted are approx.).
- Please check suitability of the product before purchasing and laying.
- If you have received a sample please be aware this is an indication of colour mix and is only a small representation of the blends that can be present.
- When ordering we recommend an extra 10% to allow for breakages or cutting
- Order all materials to complete your project at the same time.
- If using more than one pack, please ensure that you lay the product at random from all packs to minimize any unavoidable shade variations.
- Consider where you will be laying the product. If the area is shaded it is more likely to attract organic growths that result in stains. Additionally, some products may fade if situated for long periods in direct sunlight
- Always lay paving to the correct falls to avoid water pooling on the paving
- Always inspect the paving before installation
- Deliveries to site/residential addresses will be delivered kerbside from our merchants. It is important the driver has easy access when delivering.
- Deliveries made via a Pallet service have a maximum weight of 1200kgs (1000kgs if a tail lift is required).
- No claims can be entertained once the product has been laid.
- Castacrete recommend that all products are laid by a professional contractor.
Laying the paving
TIPS AND SUGGESTIONS FOR LAYING BOTH MANUFACTURED CONCRETE AND NATURAL STONE PAVING PRODUCTS.
This is not a comprehensive step by step guide, only a recommendation! Always seek professional advice.
The paving you have chosen should be seen as the ‘top dressing’ to your patio, but the key to achieving the visual result that enhances your garden is to get the preparation, installation and finishing correct. This will ensure that your new paved area will give you many years of use and pleasure. Choose products and methods suitable for your project, non-professionals should seek advice.
Preparation and Drainage
Always allow sufficient drainage when siting the patio and in preparation of the base. Poor drainage may lead to water retention which could affect the weathering and performance of the paved area.
- Drain away from the house, wherever possible. If the design of the area does not allow this, then drainage channels along the length of the property must be installed.
- Paving should be laid with a fall of 1:80.
- Surface level of the paving should be two courses below the Damp Proof Course of the property.
Laying
- All flags need to be laid on a full mortar bed, with no gaps or voids beneath.
- Do not “Dot & Dab” any stone or concrete product.
- Mortar to be mixed to the ratio of 5:1 sharp sand and cement. Light coloured paving could suffer from discolouration, so we would recommend a silver sand and white cement.
- Full mortar bed to be a 35mm-55mm depth.
- Check levels constantly while you work.
- BEWARE Natural stone is laid with the narrowest surface facing the ground, making an inverted ‘V’ joint.
- When laying Natural Stone, the jointing gap will typically be 10mm measured at the upper face, depending on the laying pattern selected and the finish on the flags edge.
- On concrete paving, the gap between slabs should be sufficient enough to allow a key for the jointing mix. NB: Some manufactured paving has a sloping side, making a ‘V’ joint. The base of these slabs must not be touching.
- There are many different ways to join your paving. Using a building sand and cement mix to the ratio of 3:1 is the traditional technique. There are a number of resin/polymeric based brush in products on the market that are just as effective.
- Castacrete recommends Joint-Ex and Joint-ExExtra Fine Permeable Jointing products.
- If you decide to butt joint Natural Stone this can potentially cause a number of issues once the stone is laid like spalling where the stone starts to chip due to direct contact with other slabs and it also encourages delamination where the stone starts to chip and flake
- Brush of any excess mortar or grouting from the stone before it dries taking care not to stain the surface.
- Refrain from using a new patio for the first 24-36 hours, so the mortar can set. After 3-5 days, the patio should be ready for full use.
Cutting
- Avoid cutting concrete paving wherever possible. If absolutely necessary, it is advised that the slab is cut with an angle grinder and diamond cutting blade. Always try to cut in a straight line and avoid cutting angles.
Characteristics of Manufactured Paving
Our Concrete paving products are designed for decorative use and enjoyed in a domestic garden environment. They are subjected to all extremities of weather and general wear and tear. Concrete is a natural material and it will react with its environment. The reactions seen, particularly on a newly laid concrete patio area, will not be detrimental to the long term use if the paving has been used in an appropriate manner. The following are some points to be aware of:-
Dark Patches
Darker or lighter areas, often appearing in the centre of the paving slab, but can also be seen as uneven patches over the whole surface. The occurrence of this chemical reaction is determined by environmental conditions, such as the amount of the shade or sunlight the area receives, or dampness from surrounding areas, rainfall frequency etc., Their appearance is therefore spasmodic, unpredictable and unavoidable. They will weather out as the slab dries naturally and incidences will reduce as the paving matures in its environment. If a blemish free area is required, alternative materials may need to be considered.
Surface Marks
Scratches or scuff marks on the surface caused in storage and in transit. Surface blemishes caused in transit cannot be avoided and do not affect the long term performance of the concrete. These will fade and weather through normal use.
Characteristics of Natural Stone Paving
Finish and Sizing
As part of the production process, natural stone will contain blemishes, veining, small chipping and small holes. All of which are natural characteristics of the stone. Most chips will not be visible once installed and pointed. Order an extra 10% for wastage, cuts and pieces that you may not wish to use.
Natural Stone varies in colour, texture, markings and touch. These variations are what give natural stone is uniqueness and add to its appeal. Small samples will not always give an accurate reflection of how the patio will look once finished. Therefore, we recommend you visit one of our stockists who will be more than happy to advise you. These variations are accepted as unavoidable within the landscaping industry. Natural Stone will have a dimension tolerance of +/- 5mm.
Colour Variations
All natural stone contains a variation in colour, veining, shading, may contain blemishes and other natural characteristics. These are all perfectly normal and not a sign of any fault in the product. Natural shade variations need to be evenly distributed across the paved area. If multi packs are ordered, open and sort all crates so a good colour mix can be achieved.
Grey Sandstone contains natural iron and this may oxidise and show as brown markings. This is inherent in the stone and should not be seen as a fault.
Black Limestone may lighten as a result of natural light and weathering.
Please contact your stockist or speak with a professional contractor for advice. Castacrete cannot be held responsible or accept liability for natural characteristics within the stone.
Characteristics of Granite Stone
Granite is natural rock; it's innately filled with imperfections such as veining, chips and variations in color. Dark or solid colored granite shows natural imperfections, dings and spills more easily than lighter granite. There is a difference between a “crack” and a “fissure.” Fissures (veins) occur naturally in the stone and are created during the rock’s formation.
This is not considered a fault in the product, but an inevitable feature that often adds to the natural beauty.
Maintenance and aftercare of concrete and natural stone
To keep your patio in its best condition, regularly sweep and clean normal garden detritus immediately to prevent staining. DO NOT use harsh acid base chemical cleaners or power washers to clean decorative paving. Sufficient cleaning can be achieved by the occasional wash with mild soapy water and thorough rinsing.
Sealer
Sealants will often change the look of the paved area and it is the owner’s choice whether to do this. We suggest you take the advice of your installer. If the decision is taken to seal we advise that the area should be clean and perfectly dry before the commencement of sealing.
Use an impregnator that will penetrate deep into the stone. This will inhibit water and oil passing through the surface and help prevent staining.
Always follow the manufacturer’s installation advice on any product applied to our products.
Regularly clean with a light jet wash each season. We recommend waiting at least 30 days before you jet-wash your new paving to avoid any issues and always use a market leading brand of stone cleaner to keep your stone looking brand new. DO NOT use acid-based cleaners.
De-icing
Do not use any form of salt, especially rock salt to de-ice paving. This may cause immediate and irreparable damage and regular application of salts will undoubtedly cause long term breakdown of the concrete. NB: Castacrete wet cast concrete paving products are designed for domestic use only and whilst they are fit for purpose under normal weather conditions, they cannot be guaranteed for use in areas which regularly experience prolonged dampness or occasional temperatures of below -15°C.
Efflorescence
The Castacrete Group of Companies cannot accept any liability for the temporary effects of the natural phenomenon of efflorescence. This can occur in both concrete products with a high cement content and some types of Natural Stone. This white powdery like substance is extremely common on both un-laid and laid concrete products. It ranges from a mild bloom which gives the appearance of colour loss to large white blotches on the surface. Its appearance can be very spasmodic and unpredictable, but is not detrimental to the performance of the concrete. It can also show itself as streaks or a mottled or spotted effect. Although most commonly associated with concrete paving products, efflorescence can also affect natural stone when it is laid on a full mortar bed. Limestone products can be particularly susceptible. This is a temporary phenomenon caused by the chemical reaction between water and cement, which will weather out naturally and does not damage the paving. There are many efflorescence removers available for purchase on the market, but we recommend it is left to weather out naturally to avoid any damage to the surface of the paving. Efflorescence is not a fault of the manufactured or natural stone.
Moss, Lichen, Algae & Weeds
It’s recommended that the following be removed by scraping out the joints. Weeds however should be removed by hand. Then treat the area with a weed or moss killer. It’s best to be applied in dry weather. After being applied it should take a few days to be fully effective. Once growths have been killed, they can easily be brushed off. Anti-moss and weed killer can also leave a residue in the sand joint which will assist the likelihood of re-growth. The manufactures instructions should always be followed with any cleaning agent.
Green & Black Staining
There are a variety of causes for staining on paving. These are shaded areas that cannot dry, poorly drained areas where water can sit. Fallen leaves which have been left and generally damp areas and can encourage black lichen to feed off the minerals and eventually being absorbed into the paving over time making difficult to remove. The best remedy is to regularly sweep your paved area to avoid growths. Use a soft bristled brush as wire can scratch the surface
Other Stains & Iron Imperfections
Clean accidental stains immediately with a proprietary cleaner specifically formulated for the job and following the manufacturer’s instructions for use. Very rarely some Natural Stones and the natural aggregates used in concrete manufacture contain small particles of iron or lignite. When exposed, the iron oxidises and the lignite may cause a reddish-brown stain. Clean with a product specially formulated for rust or lignite removal. Some weed killers and grass treatments contain chemicals that stain concrete and stone. If they come into contact with the paving, clean immediately (see above MAINTENANCE).
Do not leave any metal garden furniture on paving for long periods of time. Regularly move the furniture and clean the paved area
A choice of specialist concrete cleaners is available through builders’ merchants and good DIY outlets.
Health and Safety
- Store packs on level/even ground
- Open packs at ground level
- Stand to one side when removing strapping and wrapping
- Support leaning slabs as necessary.
- We recommend gloves are worn when handling product
- Some products are an awkward shape or weigh more than 25kgs. If lifting any such products we recommend more than one person assists, or that suitable lifting equipment is used
- Please ensure that suitable eye protection and respiratory protection is worn to avoid inhalation of dust particles.
Disclaimers
Castacrete Limited Concrete Products are made from high quality aggregates, cement and inorganic pigments and are specifically designed for domestic use. We are continually improving the quality and service we provide; therefore, information may be subject to change without prior notice. Although we take every care that the information given in our brochures or on our website is accurate and up to date, no liability of any kind (including liability for negligence) will attached to the company or their representatives. Colours and finish of products shown in this brochure are as accurate as the printing process will allow, but we strongly advise that you view the actual product before purchase. All sizing is nominal (imperial sizes where quoted are approximate). No responsibility is accepted for use of the product other than that intended by the manufacturer. Please note that the products shown in this brochure does not guarantee availability. Although not affecting your statutory rights, please note that the company cannot accept liability in respect of any costs incurred as a result of uplifting and relaying defective product, if, upon inspection it is proven that the defect ought to have been evident prior to laying. Products, sizes and quantities are correct at the time of printing.
Any technical information provided by Castacrete in relation to any product (before or after order) is provided by way of guidance only
NB: Castacrete Limited does not offer a garden design or advisory service for laying paving.