Tierrafino Stone Tadelakt

Tierrafino Stone Tadelakt is available in Delphi white to which pigments can be added for colour. It is also possible to make a choice from a pre-coloured range: Roman Ochre, Nassau Orange, Djenné Red, Iquitos Green and Gomera Grey. These standard colours have been pre-mixed with 100% natural earth pigments. As Tierrafino Stone is a natural product, small variations in colour may occur.

Delphi White Roman Ochre Nassau Orange Djenné Red Iquitos Green Gomera Grey

(Please note: this chart is for illustration only and is not intended to constitute accurate colour reproduction)

When creating a new colour use only lime- and cement-resistant fresco pigments. These can be added up to a maximum of 10% of dry mass (i.e. 90% Delphi White/10% pigment). A minimum of pigments should be used on floors (1-2%). Please note that pigments have differing influences on the behaviour of Tierrafino Stone: before starting work it is always advisable to work up a sample area.

All suitable substrates for Tierrafino Stone have the same criteria:

• They must act as a good mechanical key. Tierrafino Stone sets mechanically as it contains no glue. This means that the surface of the substrate must be rough, with particles sticking out and with small cavities (1 - 4 mm).
• They should not absorb water too quickly. Strongly-absorbent surfaces should be thoroughly moistened before applying Tierrafino Stone. They can also be treated with Tierrafino Fix. (See Tierrafino Fix sheet for details and safety advice).
• They must not be continually wet.
• They should enable Tierrafino Stone not to dry out too quickly. One of the properties of lime is that it gains strength when it dries out slowly. Keep doors and windows closed during and after application, and prevent any heat sources such as heaters, lights and direct sunlight from drying the lime out too quickly.
• They should not warp when they come into contact with the water contained in the plaster. This is to avoid structural cracks.
• They must be stable: any shrinkage or expansion of the background can cause cracks in the surface of the finish.
• All substrates must be clean, dust- and grease-free before any new layer (Tierrafino Stone, concrete or tile glue) is applied. If necessary, ammonia should be used to remove any grease.

Tierrafino Base Clay Plaster: This is very suitable as a substrate, but only in dry conditions (i.e. not bathrooms or showers).
The surface of the plaster must be left rough. Should the Base Clay Plaster absorb water too quickly; seal the surface with Tierrafino Fix. (See Tierrafino Fix sheet for details and safety advice).

Brick Walls: These are an ideal substrate. Brick walls should be prepared by plastering on a concrete mix (1 part cement, 1 part masonry sand and 1 part 4mm crushed gravel). Make this layer at least 8mm thick; leaving the surface of the concrete rough. Allow to dry for at least 24 hours before applying Tierrafino Stone. Begin application when the concrete is hard, but not fully dried out. The surface will gain strength as the concrete and Tierrafino Stone dry out together.

Concrete: This is very suitable for Tierrafino Stone because of its rigidity.
Very smooth concrete walls: First apply a thin layer of tile glue onto the concrete and roughen this to create a good mechanical key. Then, after sufficient drying time, apply a concrete mix (as Brick Walls above) at least 8 mm thick; again leaving the surface rough.
Coarse concrete walls: these need only be treated with the concrete mix as above.
Allow to dry for at least 24 hours before applying Tierrafino Stone. Begin application when the concrete is hard, but not fully dried out. The surface will gain strength as the concrete and Tierrafino Stone dry out together.

Lime Plasters: Tierrafino Stone can be applied onto fresh lime plaster after 24 hours drying time. Leave the plastered lime rough for a good mechanical key.

Plasterboard: This is not an ideal substrate as boards are very flexible.
Stick joint tape onto joints and fill with joint filler. Apply Tierrafino Contact primer with a brush. As a non-flexible structure is required, it is advisable to then apply a concrete layer 20mm thick (Concrete mix as Brick Walls above), in which a metal mesh can be placed. Fine chicken wire of approx.10mm is suitable. Attach the metal mesh every 100mm with Tierrafino Contact covered plasterboard on the joints (through the plasterboard into the structure below). Then "throw" a concrete mix onto the mesh, making sure there is good adhesion between the glue and the concrete. Apply the concrete in stages as 20mm cannot be applied at once; and leave each consecutive layer rough to stiffen. The final layer must also be left rough to give a good mechanical key. Begin application when the concrete is hard, but not fully dried out. The surface will gain strength as the concrete and Tierrafino Stone dry out together.

Tiles: Tiled walls are also not an ideal substrate as tiles have no absorption and in most cases it is best to remove all tiles.
If working onto tiles: first clean tiles with ammonia. Apply "tile-to-tile" glue (a glue with good adhesion on porcelain) and spread out with a 4mm glue comb; then apply a concrete mix (as Brick Walls above) in a layer at least 8mm thick, leaving the surface rough. Begin application when the concrete is hard, but not fully dried out. The surface will gain strength as the concrete and Tierrafino Stone dry out together.

Wood: Wooden structures are also not ideal substrates. They must be covered with plasterboard, and then treated as for plasterboard above.

The application of Tierrafino Stone is simple, however all steps must be carefully followed and timing is very important. It is recommended to attend a course to fully understand the technique. Construction Resources hold occasional short courses in conjunction with Tierrafino.

1. Add water: Tierrafino Stone is delivered as a dry powder in buckets. Add 6l water to a 12.5kg bucket of Tierrafino Stone and close lid. Do not stir. Allow to rest for a minimum of 72 hours. On re-opening you will find an apparently dry mass. Throw the Tierrafino Stone into a plasterer's tub: add a little water and stir well to make a smooth paste.

2. Moisten substrate: All substrates , absorbent or not, should always be moistened just before application. This is to provide good contact between the surface and the Tierrafino Stone. The dryer the substrate, the more it should be moistened. Freshly-applied substrates still contain enough water to allow enough time to achieve a good finish. See the substrates sections of this page.

3. Plaster /Render: Apply the Tierrafino Stone onto the surface at a thickness of 4-5mm. Allow the plaster to dry out and stiffen, so that only the top 1-2mm is still workable.

4. Shape: Flatten the surface, or model the shape of your piece, by making circular movements with a wet wooden float. Different shapes of float may be required to create different 3-dimensional objects. To refine the shape or surface wait a short time and float again.

5. Smoothen surface: Now the wall or piece can be smoothed with a metal or plastic trowel. Using more or less pressure will either bring finer lime particles to the surface to create a variety of effects (such as staining in the Venetian style); or will make a very smooth surface.

6. To enhance effects: Before the plaster has fully dried out, (in the "wet" phase), it is possible to make fine grooves in the surface by polishing with a stone. This creates movement in the surface which can be seen in the finish by the differing angles of reflected light. The grooves will be erased to a greater or lesser extent depending on the length of time allowed before polishing with a plastic trowel. It is also possible to finish the wall or piece solely with a stone.

7. ‘Scrafito’: Before a wall or piece has been treated with soapwater, an incised design or ‘Scrafito’ may be made by scratching the surface after polishing. The scratched areas are waterproof when treated with enough soapwater. With polishing, these areas also become stronger.

8. Polish with soapwater: The finished Tierrafino Stone should be allowed to rest from 2 to 24 hours to be dry enough for polishing, depending on drying speed. (In extreme cases it may be more than 24 hours). Then polish using a mix of 15 parts water and 1 part Tierrafino Soap. If polishing with soapwater is done too soon the surface may be roughened up again by the stone. Apply soapwater to the wall with a large brush. (Do not allow trickles to run down the surface; if this happens quickly wipe away with a soft dry cloth). Make small circular movements with the stone, making sure there is enough soapwater on the surface for the stone to glide across. After polishing with the stone, put a sock into a thin plastic bag and rub over the surface with circular movements. The lime content in the Tierrafino Stone reacts with the soapwater and renders the finish waterproof.

9. Further Polishing: As long as the Tierrafino Stone remains visibly wet it is possible to compress the lime slightly by pressing; using the stone and soapwater. Bathrooms and other wet areas require further applications of soapwater; 5 coats are recommended.

After 6 weeks; apply soapwater again with a soft cloth, and rub in until the wall is dry again.

SPECIAL NOTE
Tierrafino Stone is a specialist plaster applied using techniques that differ slightly from those employed for conventional gypsum. Therefore it is essential these instructions are passed on to the applicator. Failure to do so could result in poor product performance for which Construction Resources cannot be held responsible.

Coverage
At a thickness of 5mm, 5kg Tierrafino Stone covers an area of approximately 1m².
A 12.5kg container will cover approximately 2.5m².

Tierrafino Stone Soap has coverage of approximately 125m² or 5 coats of 25m² per 500g tub.

Conditions
Air temperature and the surface temperature of the wall or object to be treated should not be below 5ºC. Keep doors and windows closed during and after application and prevent any heat sources such as heaters, lights and direct sunlight from drying the material out too quickly. Substrates should not absorb water too quickly. Strongly- absorbent surfaces should be thoroughly moistened before application. (They can also be treated with Tierrafino Fix).

Tools
Plasterer’s tub; mixer; metal trowel; plastic trowel; wooden float; decorator’s sponge; polishing stone (see below); large brush; polishing cloth; various plastic materials like bags.
Polishing stone: This should be ideally a semi-precious stone such as agate. It must have a hardness of at least 7/10; the harder the better. The stone must lie comfortably in the hand and have an almost flat surface (slightly rounded) to polish with. Basalt and granite are also suitable; they can be worked into an oval shape with rounded edges. It is possible to find good stones in mineral and fossil shops or on riverbeds.

Repairs
The area to be repaired should first be thoroughly cleaned. The Tierrafino Stone can then be reapplied and polished as before. Small repair-marks may remain visible, which can add a certain rustic charm to the finish.

Leftovers
Once water has been added, Tierrafino Stone is perishable and may be used for about 2 months, provided it is kept in a well-sealed container. The hydrated lime will set slightly in the container. By adding a little water it can be broken down again and stirred back into a paste.

Drying Time
This is dependent on air temperature, humidity, and the absorption of the substrate; the finished Tierrafino Stone will take from 2 to 24 hours to be dry enough for polishing. After approximately 1 week the final colour can be seen. After approximately 6 months the finish will be fully hardened. The walls of a shower cabinet can be used after 1 week; shower floors after 4 weeks.

Maintenance
Do not clean with aggressive cleansers. Instead use Tierrafino Soap. This will not only keep the finish clean but will also maintain the waterproofing.

Time
Tierrafino Stone is a very labour-intensive material. Allow for the application of approximately 4m² per day per operative.

Ingredients
Lime

Safety
When mixing be sure to protect eyes and hands with gloves and goggles. As a lime- based product, Tierrafino Stone will burn on the skin and especially in the eyes. If in contact with eyes, wash well with water. With prolonged irritation please visit your doctor. Keep Tierrafino Stone out of reach of children.

Storage
Dry : keep closed in the original container in a dry place. Tierrafino Stone may be kept for up to 2 years this way.
Wet : once water has been added, Tierrafino Stone is perishable, and usable for about 2 months, provided it is kept in a well-sealed container. Store above 5ºC.

Disposal
As with regular building materials. Avoid contact with the eyes. Keep out of the reach of children and animals. Do not throw any waste down the drains; always try to dispose of waste at a registered disposal dump.