Oyster

LAYING GUIDELINES FOR NATURAL STONE

1. CHECK YOUR PRODUCT

Before any work is carried out, each piece of natural stone should be inspected, both wet and dry, prior to laying as pieces will vary. No returns can be accepted once the product is installed, so it is important to confirm you are happy with your product before proceeding. When work begins, ensure the area is cleared of all vegetation and debris. Then, ideally using a scaled drawing of your planned area, you can start plot pointing by marking out the space using pegs and a string line.

2. PREPARE YOUR BASE

Dig the ground to a depth of approximately 150mm below the finished patio level (or 200mm deep below the finished driveway level), making sure the soil is compact.

3. LAY YOUR HARDCORE

In the now excavated area, spread a layer approximately 100mm deep of hardcore (or 150mm deep for driveways). Remember to leave room for the thickness of the flags and 30-50mm of mortar. Compact the layer of hardcore thoroughly, ideally using a plate compactor. Foundations must not be laid on water saturated ground as they may sink in time, creating uneven paving. Extra drainage may be required.

4. LAY YOUR SLABS

Once happy with the layout, using your line and pegs as a reference, you can start laying your flags down on a full bed of slightly wet mortar mix 30-50mm deep. For the mortar mix we advise 1 part cement to 5 parts sharp sand (some contractors use a 50/50 mixture of building and sharp sand). All products must be laid on a full bed of mortar, especially when laying a driveway. A full bed of mortar is key to help reduce moisture transparency or discolouration, as well as to provide a solid base for the patio.

An SBR bonding agent is an adhesive, waterproof barrier that should be used to help the slabs adhere to the mortar bed and can be used in conjunction with our Slurry Primer. Only requires water to mix, see page 146 for details, (or a Slurry Primer mix using cement powder, water and an outdoor based SBR bonding agent to a creamy consistency) that is to be painted onto the back of each slab with a thickness of 1-2mm before laying when using natural stone (see overleaf for specific advice on laying porcelain). Use a rubber mallet to gently tap down the flags and a spirit level to check the patio is uniformly level, being careful to check you follow your slope level as you go along. To provide suitable run-off during wet weather, a fall angle must be considered. Falls must be angled away from buildings or structures at an incline of 1:60 or steeper. An adequate drainage outlet source should be present at the end of the patio’s run off edge. A planning officer may need to be consulted for further advice. It is important to note that Digby Stone products are not designed to be butt jointed, and a suggested joint of approx 10mm should be used. For products with an aged finish we suggest to increase the joint size accordingly in order to accommodate for any potential variations in edges (between 15 - 20mm approx).

5. CUTTING NATURAL STONE

Once the main area of the patio is laid down and there are slabs that need cutting, in the case of natural stone a disc cutter with a suitable attachment or a hammer and chisel is needed to shape your flags effectively (please see our porcelain laying advice overleaf for specific guidance on cutting porcelain tiles). Once happy with the shapes of the now cut flags, you may lay them down (refer to step 4) on a full bed of slightly wet mortar mix. Using a rubber mallet, gently tap down the flags and use a spirit level to check for a uniform flatness (taking into account a fall).

6. CHECK YOUR JOINTS

 LAYING GUIDELINES FOR PORCELAIN PAVING

1. CHECK YOUR PRODUCT

Ensure that you check your product before laying – we recommend
dry laying a random selection of your tiles (from more than one pallet where applicable) to ensure that you are satisfied with the colour variation in the tiles. Claims or returns based on colour variation will not be accepted once the product has been laid. Ensure that whilst working with porcelain tiles that they are rested on wooden battens to prevent any edge chipping.

2. PREPARE YOUR BASE

Prior to installation, all necessary ground work should be completed. This includes ensuring there is a sub-base of at least
50 – 100mm thick of type 1 material (hard-core) which has been
sufficiently compacted down, with a suitable water drainage fall
(a fall of 1:60 is usually adequate).

3. PRIME YOUR SLABS

Apply Digby Stone Universal Slurry Primer (or a Slurry Primer mixed using cement powder, water and an outdoor based SBR bonding agent to a creamy consistency) to the back of each tile before it is laid to help the paving adhere to the bed. Paving slabs may need to be handled by 2 people (in particular the larger sized slabs). When applying slurry primer, ensure that you rest the tile on wooden battens to prevent any chipping.

Digby Stone’s Universal Slurry Primer only requires 7L of water per 20kg bag to produce a creamy consistency. Once mixed apply 1-2 mm to the back of the slab.

4. USE A FULL BED OF MORTAR

Just like our natural stone products, Digby Stone porcelain must be laid on a full wet bed of mortar. We recommend a mixture of a moist consistency (rather than runny) with approx. 4:1 sharp sand to cement.

5. LAY YOUR SLABS

It is essential that each tile is tapped down to ensure as much of the tile as possible comes into contact with the mortar. When
laying your project, ensure that you mix tiles to achieve an overall blended appearance. While the finishes of porcelain have less surface variation than natural stone, they are still designed with a level of variation to add a range of texture to their surface. If within the selection of tiles you encounter any repeat patterns, we suggest that you rotate slabs 90/180 degrees in order to minimise the appearance of repetition (this may be more prevalent in tiles which have a more extensive surface pattern. Don’t half bond porcelain tiles over 600mm long. We recommend maximum one third/two thirds bond for tiles over 600mm.

6. CUTTING PORCELAIN

Porcelain can be cut with a disc cutter fitted with a suitable for-porcelain diamond blade (this must be a petrol disc cutter as you must feed the disc with water to cut). However, for neater and more accurate cutting, we recommend using a suitable water-fed tile bridge saw. Ensure that appropriate protective clothing is worn while operating machinery.

7. CHECK YOUR JOINTS

Allow for 10-12mm+/- approx joints when laying the tiles.

We suggest an outdoor jointing compound (suitable for porcelain) should be used with our porcelain products – please speakto your merchant or landscaper for the most appropriate jointing compound for your project. As previously stated, Digby Stone porcelain products are not designed to be butt jointed.

8. IMPORTANT – CLEAN THE JOB

It is particularly important to work cleanly when laying porcelain, both during and after installation. Once the job is completed, additional cleaning may be required if any residue remains, particularly from jointing compounds. Ensure that the jointing compound has set sufficiently and then clean the tiles with
a suitable residue remover (depending upon which jointing compound has been used). Any residue left over from the laying process must be removed as soon as possible – failure to do so may result in staining on the surface of the tiles. If your porcelain has been laid in conjunction with any natural stone, ensure that the porcelain cleaner/residue remover you are using does not contain any acid and check they are suitable for porcelain. Any cleaners containing acid will cause damage to natural stone.