Remodelling your garden is an investment that you will probably live with for many years to come, so it’s important that you are armed with all the information you need to make the right choices. Our friendly and experienced sales advisors are always on hand to discuss your project, but we’ve also put together this handy list of frequently asked questions - covering topics such as selecting the right product, installation, cleaning and maintenance - to start you on the right path.

STONE SELECTION

I have children/pets/overhanging trees – is natural stone suitable for my garden?

There is a natural stone solution for every project. Your sales advisor will be able to assist in helping you to choose the best product to suit your lifestyle. We strongly advise that natural stone is sealed to assist with maintenance and cleaning in the future and this is even more important in high-traffic areas.

Is natural stone better than concrete?

These are two entirely different products but there are some advantages to using natural stone over concrete. Natural stone will weather naturally over time, often getting better with age, whereas concrete can lose its original colour fairly quickly. If a concrete paver is chipped or damaged then unsightly concrete and aggregate will be left on display, unlike natural stone which is a consistent colour throughout the depth of the slab.

Are London Stone’s products ethically sourced?

Yes they are. It's very important to us and something that we are firmly committed to. All of the foreign suppliers we work with comply with the ETI Base Code. We work closely with them and support them to continually improve the conditions for workers. We pay regular visits to their production sites and also work collaboratively with other stone companies to improve conditions in the broader supply chain. For more details on our ethical policies, please contact steven@londonstone.co.uk

Do London Stone have a showroom I can visit?

We have the best natural stone display centres in the country and we strongly encourage all customers to visit one of the showrooms if at all possible. There is no substitute for seeing the stone installed and pointed; it will give you a much better idea of what you’re buying than you will be able to glean from a photo or a small sample. You can also speak with our expert sales advisors who can help with any questions you may have. Our showrooms are based in Middlesex, Kent and Essex – find your nearest branch here.

Is natural stone suitable for my driveway?

We supply a lot of stone for driveways and our sales advisors can help you choose a suitable product. Something hardwearing and dense such as slate, granite or basalt is a good choice as it will be easier to maintain, whilst the darker colour will help to disguise the odd oil droplet or tyre mark. We strongly advise that any type of stone used on a driveway is sealed prior to application with one of our Dry Treat products.You will also need to install a deeper sub-base for a driveway. Please speak with your sales advisor for further information.

Does natural stone retain its original colour indefinitely?

Over a period of time exposed to the elements, your stone will weather which often involves some level of colour change. This is a positive characteristic and natural stone looks all the better for age. Some stones are more prone to colour changes than others. For example, Jura Beige Limestone, Kota Brown Limestone, Kota Blue Limestone and especially Midnight Black Limestone will tend to lighten up fairly quickly when exposed to the sunlight. The majority of customers like this weathered look, however if you’d like your stone to retain its original colouring, you can apply Dry Treat Intensifia to deepen the colour. This can be done retrospectively if you change your mind later on. Alternatively, ask your sales advisor about our pre-sealing service as we can apply the Intensifia prior to delivery.

Is stone paving slippery?

We carefully select products with slip-resistance in mind. You may have noticed that some of our products have different surface finishes (sandblasted, flamed etc.). As well as enhancing the appearance of the stone, these options provide extra grip underfoot for products which could prove too slippery otherwise. Some stones have a naturally grainy texture and don’t require an additional slip-resistant finish. It is important to ensure that algae is kept under control with regular maintenance as this can make any outdoor flooring slippery underfoot, whether it be natural stone, concrete, decking, or any other material. This is especially important in north facing gardens which tend to be algae prone.

VARIATION

My slabs are not exactly the same colour as the sample I received. Why?

Stone is a natural product and no two pieces are ever identical. Some products have fairly subtle differences from slab to slab and batch to batch, whereas others contain a lot of variation. This makes it impossible for us to show a true representation of the stone you will receive in just one 75mm x 75mm sample. We strongly recommend that you make a visit to one of our showrooms to view the stone in situ. Again, what you see at the showroom will not be identical to the stone you receive, but the more stone you can view the better idea you will have of what to expect.

My stone is darker than the sample I was expecting. Why?

As well as the natural colour differences explained in the previous answer, stone may also appear darker if it is wet. If your stone has been cut to order in our Bespoke Stone Centre then there is a chance that it could be retaining moisture from the wet cutting process. If in doubt, allow the stone to dry thoroughly prior to installation.

Some of my slabs have small chips on the edges. Why?

Processing, handling and transportation can cause small chips to the edges and corners of slabs. Although we invest heavily in packaging and take great care to get your stone to site in excellent condition, some small chips are unfortunately unavoidable and are considered the norm within the natural stone industry. The vast majority of these imperfections will not be noticeable once the stone is installed and pointed. We recommend opening all crates and arranging your slabs before commencing installation. This will allow you to set aside any slabs with larger chips to be used for cuts.

DELIVERY

How will my stone be delivered?

Delivery methods will depend on the quantity of stone ordered and the location that we are delivering to. Local deliveries are made by our in-house transport department on a hiab (crane offload) vehicle. Our drivers are very experienced, friendly and helpful. If you’d like your crates left on a driveway or front garden, we will do our best to accommodate this subject to accessibility with the crane from the roadside and the driver’s discretion.

Nationwide deliveries are made by an external pallet freight company. This is a kerbside only service so you will need to take responsibility for moving the goods off the road and onto your own property. The pallet freight vehicles use a tail lift and pump truck which means that the driver will need a flat area of hard-standing (i.e. not gravel or grass) on which to unload.

Delivery drivers are unable to carry slabs through to your back garden so please ensure you have the relevant labour organised to facilitate this. If you have any concerns about delivery methods or suitability, please speak with one of our sales advisors who will be able to help.

ORDERING

Do I need to order extra slabs for wastage?

We recommend that customers order an additional 10% extra for wastage. This will prevent your project being held up in the event of breakages or damage on site. It also means that you can discard the odd slab that you don’t like the look of due to natural colour variation, veining etc.

Do I have to buy a full crate? I only need a small amount of material.

Not at all – just buy the quantity that you need. We know that it’s really frustrating to have to order twice as much as you need so we are more than happy to split down our crates of stone if required.

How long will my order take to arrive?

The vast majority of our stone is kept in stock, meaning that we can usually deliver within just a couple of working days – often we can accommodate next day delivery requests if you order in the morning. Occasionally we do sell out of a certain product so it’s always a good idea to get your order placed as soon as you’ve made up your mind to avoid disappointment. In addition, bespoke masonry services or special orders will take more time to process so, again, the sooner you can order the better.

INSTALLATION

Can natural stone paving be butt jointed?

We strongly advise against this. Pointing is an important part of paving construction and provides stability for the paved area. Natural stone also has dimensional tolerances which make it impossible to achieve an even finish by butt-jointing. Butt jointing leaves gaps, albeit tiny ones, between slabs and so it can also encourage weed growth and leave the paving vulnerable to damage from freeze/thaw action.

What size should pointing gaps be?

For riven paving we recommend a minimum pointing gap of approximately 10mm. For sawn stones, we recommend a minimum gap of around 5mm. Any dimensional differences in the slabs should be allowed for in the joints to give you an even overall finish.

Do you offer an installation service?

Unfortunately not - we like to focus all our efforts on supplying the best quality natural stone paving we can. However, you can use our Connect service to find a garden designer or landscaper in your area. As with any project of this nature, please ensure that you check the companies’ portfolios carefully to see examples of previous work and obtain alternative quotations before you agree to any work taking place.

Which way up should I lay my riven sandstone? Does it matter?

There is a top and a bottom to all natural stone slabs. The top will always be the better looking side. With riven sandstone, the top will have a larger, flatter surface and the edges will taper in slightly towards the bottom of the slab. If in doubt, just get in touch and we will be happy to assist.

How do I install stepping stones?

Stepping stones should be installed the same way as the main patio; on a compacted MOT type 1 sub-base with a full bed of sand and cement mortar.

Can I install natural stone using a pedestal system?

Pedestal systems are often used where weight is an issue, for example on balconies. We recommend that stone is a minimum of 50mm thick, no larger than 600x600mm and that you also place a central support in addition to the edge/corner pedestals. Since we do not stock a pedestal system ourselves, we strongly advise that you check all details with your pedestal system supplier prior to ordering your paving products.

SEALING WITH DRY TREAT

Does natural stone need to be sealed?

We always advise sealing your natural stone with Dry Treat Stain Proof. This will make cleaning and maintenance much easier and will help to prevent permanent staining to the stone. This is even more important in high traffic areas. For example, a driveway is likely to suffer the occasional oil droplet or tyre marks, overhanging trees can drop sap, BBQs will mean spillages of drinks, fat and food, pets may tread muddy paw prints across the patio. In all these instances, it’s strongly advised that you seal your stone to help protect against permanent stains.

Please note; a sealant will not negate the need for a cleaning and maintenance program. Whilst Dry Treat will help to protect against permanent stains which are absorbed into the stone, it will not stop marks, footprints, spillages etc. from appearing on the surface of the stone. The aim of the sealant is to make these marks easier to clean off so that, with the right cleaning regime, your stone can be brought back to its best.

How long after installing the stone can I apply a sealant?

Ideally, the sealant should be applied prior to installation. This allows you to help protect the stone during the installation process and will also help to prevent efflorescence. If you’ve already installed the stone, you can still seal it retrospectively. In this case, you must ensure that the stone is clean and completely dry all the way through – please be aware that stone can appear to be dry on the surface whilst still retaining moisture underneath. For this reason, sealing is best done after a period of warm, dry weather which will mean waiting until spring or summer. Do not seal stone which is showing signs of efflorescence (a cloudy, whitish bloom on the surface, caused by salt particles being drawn up through the stone from the bedding layer). We recommend waiting at least 6 weeks after installation before applying a sealant to be sure that efflorescence is not going to occur.

What happens if you seal stone before/during efflorescence?

This will make the efflorescence much more difficult, or impossible, to remove. We strongly recommend sealing the stone prior to installation to help protect against efflorescence – we can pre-seal the stone before delivery for you. Efflorescence, characterised by white, cloudy marks, is caused by salts from the bedding layer leeching through to the surface of the stone. It is a temporary phenomenon, affecting only a small percentage of projects, which will disappear on its own over time. Unfortunately this can take a couple of weeks, several months or even longer. You can speed up the process by regularly cleaning the stone but ultimately the efflorescence must run its course.

What happens if I seal stone which is dirty or wet?

Dirty marks will be much harder to clean if you have applied sealant over the top of them. The sealant will have coated the particles of dirt, potentially missing patches of the stone itself and meaning that you may also need to reapply more sealant after you’ve cleaned the marks off. Sealing when the stone is wet means that the sealant will effectively become diluted and will not perform as effectively as it should. Again, this will require re-sealing which adds additional cost.

Is it possible to over apply the product?

The stone will reach a natural saturation point, meaning that no further sealant can be absorbed. Any excess sealant needs to be wiped away from the surface. Leaving excess sealant on the surface will cause sticky, shiny patches so it’s important to ensure that they are wiped away as per the sealing guide.

What happens if I put more sealant on one area than another?

It’s best to apply your sealant with a spray applicator to ensure an even coverage. If you follow the directions closely, apply the recommended number of coats and make sure to wipe away any excess then you should find that coverage is even across the paved area. Any areas which have not received a full application of Dry Treat, as per the directions on the packaging, will not be fully protected and will require further application.

What happens if the paving gets wet before the sealant has had chance to dry?

This is another benefit to having your stone pre-sealed by us before delivery – we seal the stone indoors and it arrives with you ready to install. If you’re planning to seal the stone after installation, check the weather forecast and wait for a period of warm, dry weather. If it does rain after you apply the sealant, the effect on your stone will depend on how quickly the stone got wet after sealing and how much it rained. A very light shower 4 hours after the sealant is applied may mean that you need to apply an extra coat of sealant once the stone is dry again. A torrential downpour or someone jet-washing the stone may require sealing again from scratch once the stone is dry.

Should I seal the bottom of the slabs for extra protection?

Please make sure that you seal the surface only – sealing the underside of the slabs could affect adhesion between the slab and the bedding layer. It also won’t offer any additional protection for the stone and will cost you twice as much money.

I didn’t wipe away all the excess sealant and now there are shiny patches of dried sealant on the surface of the stone. How can I get rid of them?

In the first couple of days or so after sealing, you should be able to remove any excess using a clean, white cloth dampened with the original sealing product. In hot weather this time window will be narrower. Acetone can be used in the same way for about the next 7 days. After this time period, the sealant will have cured and will be exceptionally difficult to remove.

How soon after sealing can I jet-wash the stone?

We recommend waiting at least 30 days before you jet-wash your paving to avoid any issues.

CLEANING

Can I use a patio cleaner on my natural stone?

The content of natural stone can sometimes react with certain types of chemical cleaner so it’s always best to check with one of our sales advisors before you use a patio cleaner. Always test cleaners on a small area before full application and never use an acid based cleaner on limestone or basalt paving – the acid will react with the stone and cause permanent damage.

What’s the best way to remove organic marks or general dirt and grime from my natural stone paving?

For general dirt or organic marks like grass stains, mud etc. we recommend Lithofin Outdoor Cleaner. Just dilute, apply and jet-wash off as per the instructions on the bottle. When cleaning your stone, you will find that a jet-wash (possibly in conjunction with a chemical cleaning agent, like Lithofin Outdoor Cleaner) will give the best results. This is because dirt particles enter the pores of the stone and the mechanical action of the jet-wash is needed to lift them out – just don’t hold the jet-wash too close to the surface of the stone otherwise you may cause etch marks. About 600mm away is perfect.

How can I remove cement or stubborn marks from my natural stone paving?

For stubborn marks or cement based stains, Lithofin Builders’ Clean is a better choice, although this is acid based so cannot be used on limestone or basalt products. Cement is notoriously difficult to remove once it’s dry since it becomes engrained in the pores of the stone, so it’s much better to clean any spills as they happen during installation or pointing with clean water and a sponge. When cleaning your stone, you will find that a jet-wash (possibly in conjunction with a chemical cleaning agent, like Lithofin Builders’ Clean) will give the best results. This is because dirt particles enter the pores of the stone and the mechanical action of the jet-wash is needed to lift them out – just don’t hold the jet-wash too close to the surface of the stone otherwise you may cause etch marks. About 600mm away is perfect.

My stone is sealed but the surface is marked with footprints. I’ve hosed down the stone but they won’t come off – why?

Sealing your stone will help to protect against permanent stains and will make cleaning much easier in comparison to unsealed stone, however it will not stop marks from appearing or make the stone ‘self-cleaning’. Dry Treat is an impregnator, meaning that it coats the particles of the stone to around 6mm under the surface and leaves the pores of the stone open. Lesser quality sealants coat the entire surface of the slab like a varnish. This surface coat often causes an unsightly sheen and can wear away very quickly, especially in areas that get a lot of foot traffic. This is what makes Dry Treat such a long lasting and cost effective solution. The fact that the pores remain open means that mud from animal prints or rubber from shoe soles can become engrained in the pores of the stone and will need to be jet-washed to lift the dirt particles out. On pale and porous products in particular, the first couple of marks on the stone will stand out since the product is brand new and completely clean. Rather than rushing to jet-wash the stone, we advise that you allow it to weather in a little bit. Over a period of time exposed to the elements the marks will become less noticeable and the odd footprint or mark will not stand out. You can then begin a regular cleaning regime which involves jet-washing the stone, possibly in conjunction with a chemical cleaning agent, once or twice a year.