Notes on Material Properties, Manufacturing Tolerances, and Installation of Mosaics

1. General Note on the Nature of the Product

Mosaic is a handcrafted and partly natural product. Absolute uniformity in color, shape, surface, and structure is neither technically possible nor desired. Each mosaic tile is unique. Slight variations are therefore characteristics of authenticity and the manufacturing process and do not constitute a defect.

Production is carried out in batches. This may result in technical differences between individual deliveries. Material properties, firing processes, and raw materials may cause minor differences in color, surface, and structure.

2. Batch-Dependency and Reorders

Since mosaics are produced in batches, we cannot guarantee that the tone, color gradient, surface texture, mesh backing, or stone size of subsequent orders will exactly match those of the initial delivery.

Important Note

We therefore recommend ordering an adequate surplus quantity, including waste and replacement material, with your initial order. This is the only way to avoid subsequent color or batch variations when reordering.

3. Color, Gloss, and Reflections

The color of mosaic tiles is never completely uniform or homogeneous. Color variations result from the material, raw materials, firing processes, and lighting conditions.

Special Features of Glass Mosaics

• Depending on the batch, glass mosaic may exhibit a greenish, purple, or other colored sheen.
• This is not a defect, but a characteristic property of the material.
• Differences depend, among other things, on the incidence of light, viewing angle, substrate, and the type of installation.
• Differences in gloss level or slight metallic effects are also material-related.

These characteristics do not constitute grounds for a complaint.

4. Production-related deviations and tolerances

Depending on the material, format, and processing, the following tolerances are technically necessary:

• Dimensional deviations in mosaic tiles (e.g., 300 × 300 mm ± up to approximately 3%),
• minor differences in stone size,
• Differences in material thickness,
• slightly varying joint widths,
• different surface textures,
• Color variations within a mat or between different mats.

These characteristics correspond to the state of the art and the nature of the product and do not constitute a defect.

Many of our mosaics are manufactured in accordance with the requirements of DIN EN 14411. Visual quality control is performed in accordance with the testing standard EN ISO 10545-2.

During production, dimensional and surface deviations are technically unavoidable. According to applicable testing standards, at least 95% of the surface area per square meter must be free of defects. This means that up to 5% of the surface area may exhibit minor visual characteristics such as small chips or irregularities.

These are usually replaced by qualified personnel during installation or are no longer visible after grouting.

Assessment is carried out under an illuminance of 300 lux, from a viewing distance of one meter, and at a viewing angle of 90°.

 

5. Irregularities, scratches, chipped edges, and individual damaged tiles

Small chips on corners and edges (so-called edge chipping), fine scratches on the surface, and minor irregularities in the shape, size, and surface area of individual mosaic tiles are natural characteristics of the product and do not constitute a defect.

It may happen that:

• individual tiles have fallen off,
• individual tiles are completely missing,
• individual tiles were installed incorrectly,
• Individual tiles may have scratches, chips, or minor damage.

Depending on the format of the mosaic tile, there are between approximately 100 and 1,000 individual mosaic tiles on a surface area of one square meter.

It is technically and economically impossible to deliver every single stone without defects.

It is rare for mosaic shipments to arrive 100% free of defects. Rather, it is the exception rather than the rule that there are no minor defects at all.

Given the thousands of mosaic tiles produced, packaged, and shipped daily, it is neither economically nor technically feasible to inspect each tile individually. For this reason, the boxes are not opened to check each individual tile for minor visual defects.

Even with the utmost care during manufacturing, packaging, and shipping, individual tiles may become damaged.

Minor defects are typical characteristics of the product and can be corrected during standard installation work.

For this reason, these characteristics are expressly described in the product information and are part of the standard product characteristics.

6. Industry-standard tolerances and quality standards

It is standard industry practice that approximately 1 to 5% of the tiles per mat or square meter may be broken, scratched, have small chips, or be otherwise damaged.

These characteristics do not constitute a material defect and generally cannot be recognized as grounds for a complaint.

Even after installation and grouting, material-specific stresses may cause individual tiles to crack, or a damaged tile may have been overlooked during installation.

This does not constitute a hidden defect, but is a natural characteristic of mosaics and must be taken into account during installation.

Many of our mosaics are manufactured in accordance with the requirements of DIN EN 14411.

Visual quality control is performed in accordance with the EN ISO 10545-2 testing standard.

Dimensions and surface variations are possible during production.

With regard to surface quality, at least 95% of the area per square meter must be free of defects.

This means that up to 5% of the surface may exhibit minor visual characteristics such as small chips, chipped edges, or irregularities.

These are usually replaced by qualified personnel during installation or are no longer visible after grouting.

Assessment is carried out under a light intensity of 300 lux from a viewing distance of one meter at a viewing angle of 90°.

7. Obligation to Inspect and Installation

Each individual mosaic sheet must be carefully inspected before installation.

In this regard, both the front and back sides must be inspected for the following points:

• defective tiles,
• unsightly stones,
• missing tiles,
• incorrectly installed tiles,
• Foreign objects,
• Damage,
• Color variations,
• Surface defects.

Damaged or visually unsightly tiles must be removed from the mat.

The mat is then laid.

Any gaps will be filled with suitable replacement tiles from offcuts or available replacement material.

A dry layout prior to final installation is strongly recommended.

In particular, the following should be checked:

• Color gradient,
• Sample image,
• Grout pattern,
• Differences in size,
• Batch variations,
• overall visual effect.

Any noticeable deviations must be assessed prior to installation.

Mosaics and tiles with visible aesthetic defects that exceed permissible manufacturing tolerances, appear unsightly after grouting, or could be visually objectionable in the opinion of the customer or a specialist company must be sorted out by visual inspection prior to installation and must not be installed.

A decision regarding this must be made together with qualified personnel before installation work begins.

Installation despite recognizable defects generally excludes warranty claims regarding these visible characteristics.

Claims regarding tiles or mosaics that have already been installed and had visible defects prior to installation cannot therefore be accepted.

Even after installation and grouting, individual tiles may crack or previously unnoticed damage may become visible due to stresses typical of the material.

This does not constitute a hidden defect, but is part of the product’s natural characteristics.

8. Replacement of defective tiles before and during installation

The replacement of individual damaged or missing mosaic tiles is part of standard installation procedures for mosaics and constitutes a normal part of professional installation.

When installing mosaics, the following procedure is generally followed:

A) Inspection of mosaic sheets

Before installation, each mat must be carefully inspected on both the front and back sides.

In particular, the following should be checked:

• damaged tiles,
• missing tiles,
• loose stones,
• incorrectly installed tiles,
• visually objectionable tiles,
• Foreign objects,
• Transport damage.

B) Removal of Damaged Tiles

Damaged, missing, or visually unsightly tiles must be removed from the mat before installation.

This is a standard craftsmanship practice in the installation of mosaics.

C) Installation of the mat

After removing the affected tiles, the mat is installed in accordance with the applicable installation guidelines.

The missing sections remain blank for now.

D) Replacement of Individual Tiles

The empty spaces are then filled with suitable stones from the offcuts or available replacement material.

If no suitable replacement tile is available or the damage exceeds the usual scope, the customer may submit corresponding photos as proof.

In such cases, we will consider a free replacement delivery as part of our goodwill policy.

Alternatively, a suitable stone from the offcuts can be used and attached to the empty space using a suitable adhesive dot.

E) Final Inspection

After installation and grouting, the surface should be inspected again.

Should any additional damaged tiles be found, these may also be replaced.

Replacing individual tiles is part of standard installation procedures and does not constitute an extraordinary amount of work.

9. Waste, Replacement Material, and Industry-Standard Tolerances

It is common practice and recommended by specialist companies to allow for sufficient waste when working with mosaics, tiles, borders, and similar products.

These include, among others:

• Cuts,
• Corner areas,
• Edge areas,
• Recesses,
• subsequent repairs,
• Replacement of individual damaged tiles.

An approximate proportion of 5% of offcuts or replacement material is considered standard industry practice.

Similarly, a proportion of approximately 1 to 5% of damaged stones, tiles, borders, or panels is considered normal and generally does not constitute a material defect.

As a company, we nevertheless strive to find a customer-friendly and accommodating solution.

In individual cases, we will inspect damaged deliveries and, where complaints are justified, provide a replacement free of charge whenever possible.

We generally recommend ordering approximately 5% extra as a reserve and replacement supply.

This allows for minor damage or necessary cutting to be addressed without delay.

In many cases, offcuts and individual damaged tiles do not need to be disposed of.

They are often suitable for:

• Edge areas,
• Corners,
• Recesses,
• Repair work,
• subsequent replacement work.

10. Grout pattern and visual appearance

Every mosaic tile is unique.

Slight differences in:

• Stone format,
• Grout width,
• Stone spacing,
• Surface texture,
• Material thickness,
• Color intensity,

are part of the product’s natural appearance.

Irregularities in the grout pattern do not constitute installation errors, but are a deliberate design element of mosaics.

In particular with transparent mosaics, the mesh or the adhesive may show through.

This is due to the nature of the material and cannot be completely avoided from a technical standpoint.

With white or light-colored mosaics, visual effects may occur when used in combination with white adhesive or white grout.

These include, for example:

• spotty appearance,
• Shadowing,
• varying brightness effects.

These effects depend in particular on:

• Light source,
• Viewing angle,
• substrate color,
• Adhesive color,
• Grout color,
• Daylight and artificial lighting.

They do not constitute a product defect.

11. Installation and Warranty

The installation of mosaics must be carried out in accordance with recognized technical standards.

Only suitable substrates, adhesives, grouting materials, and installation methods may be used.

Upon commencement of installation, the installer confirms that the material, with regard to

• Color,
• Format,
• Surface,
• Structure,
• Consistency within a batch,
• visible damage,
• obvious material defects

has been inspected and is suitable for installation.

Material that is processed despite recognizable defects is deemed accepted with regard to these properties.

Warranty claims based on characteristics or deviations visible prior to installation can generally no longer be asserted once the installation has been completed.

This is in accordance with the recognized rules of the tile and mosaic trade.

12. Adhesive Bonding – Mesh, Film, and Special Adhesive Bonding

For mosaics with mesh, film, or special adhesive backing (e.g., PU film, PET film, or comparable carrier materials), only suitable adhesives and grout materials in accordance with the manufacturer’s instructions may be used.

In particular, with transparent glass mosaics or special mosaics, unsuitable adhesives can cause permanent visual changes.

For certain products, the use of an epoxy-based reactive resin adhesive may be required.

For example:

• Mapei Kerapoxy,
• comparable reaction resin systems from other manufacturers.

Cement-based adhesives or unsuitable substrates may cause chemical reactions.

This may result in, among other things:

• Cloudiness,
• Discoloration,
• so-called opacity,
• permanent visual changes.

Damage resulting from unsuitable materials or improper installation does not constitute a warranty claim.

The manufacturer’s specifications for the construction chemicals used and the recognized rules of the art must always be followed.

13. Special Notes for Swimming Pool and Pool Mosaics

For swimming pools, wellness facilities, water basins, and other permanent underwater areas, only materials suitable for this purpose may be used.

For glass mosaics, paper-backed material is generally recommended.

Paper-backed mosaic offers significant advantages over mesh-backed mosaic.

In particular:

• better adhesion,
• full-surface bonding,
• reduced risk of voids,
• reduced risk of leaks,
• better visual results.

Adhesive mesh backing may reduce adhesion and, depending on the installation, lead to voids.

The mesh may be visible in transparent materials.

This effect does not occur with paper-backed mosaics.

The substrate must generally:

• load-bearing,
• clean,
• dry,
• even,
• smooth,
• as white as possible,

be carried out.

This is the only way to achieve a visually uniform final result.

Installation must be carried out in accordance with the manufacturer’s instructions for the adhesives and grout materials used.

14. Sample Orders

Mosaic samples are intended solely for general guidance regarding:

• Color,
• Material,
• Surface,
• Structure,
• Feel.

Samples are usually supplied in small formats.

Due to batch production, we cannot guarantee that a subsequent delivery will correspond exactly to the sample.

In particular, differences may occur in:

• Color,
• Shading,
• Gloss level,
• Stone format,
• Surface texture.

This does not constitute a defect.

Samples are generally excluded from exchange.

We recommend carefully examining samples before placing a large order.

15. Summary – What Does Not Constitute a Defect?

The properties listed below are typical material and product characteristics and do not constitute a material defect:

Material and Batch

• Color differences between batches,
• varying shades,
• varying shades,
• different surface textures,
• varying degrees of gloss.

Dimensions

• minor dimensional deviations,
• different stone formats,
• varying material thicknesses,
• varying joint widths,
• Dimensional deviations of the mats.

Surface

• Edge breakage,
• minor chips,
• fine surface scratches,
• light scratches,
• minor surface irregularities,
• Production-related dimensional variations.

Individual tiles

• loose stones,
• missing tiles,
• incorrectly installed tiles,
• individual damaged tiles,
• up to approximately 1 to 5% of stones that are damaged or need to be replaced,
• Minor shipping damage to individual tiles.

Visual Properties

• visible mesh structures in transparent material,
• Differences in gloss,
• Color shimmers,
• metallic reflections,
• varying light effects,
• visual changes due to the substrate or grout color,
• Shadowing,
• spotty appearance under certain lighting conditions.

Installation

• Replacement of individual tiles,
• Use of replacement stones from offcuts,
• Stress cracks in individual tiles after installation,
• Minor damage that can be remedied during standard installation work.

16. Final Notes

Mosaics are high-quality handcrafted products and differ fundamentally in their installation from large-format tiles.

Minor visual irregularities, individual damaged tiles, and slight deviations in dimensions and color are part of the characteristic appearance and are technically unavoidable.

Before installation, the installer must thoroughly inspect the material for obvious defects, damage, and deviations.

Upon commencement of installation, in particular through cutting, bonding, or grouting, the material is deemed to have been inspected and accepted with regard to its visible properties.

Obvious characteristics or recognizable deviations that could have been detected prior to installation generally cannot be the subject of a complaint after installation has been completed.

Installation must be carried out in accordance with recognized technical standards and the manufacturer’s specifications for the building materials used.

We generally recommend ordering a sufficient surplus quantity to account for waste, replacement material, and any future repairs.

Our goal is to provide our customers with high-quality products. At the same time, we would like to point out that the properties described represent typical characteristics of mosaics and, when installed properly, have no impact on the suitability for use or the overall visual effect of the finished surface.

17. Legal Notices, Warranty, and Installation Guidelines

17.1 Obligation of the Buyer and Installer to Inspect

The buyer and the installer are obligated to carefully inspect the delivered material before beginning installation.

This includes, in particular, the inspection of:

• Quantity,
• Color,
• Batch,
• Format,
• Surface,
• Product attributes,
• visible damage,
• Transport damage,
• obvious material defects.

The inspection must be carried out under adequate lighting and before cutting, gluing, or grouting.

Any identified defects must be reported before processing begins.

17.2 Installation is deemed acceptance of visible characteristics

Upon commencement of installation, in particular through

• Cutting,
• Adhesive bonding,
• Grouting,
• Installation,
• Processing,

the material is deemed to have been inspected and accepted with regard to its visible properties.

These include, in particular:

• Color,
• Tonal range,
• Surface texture,
• Gloss level,
• Stone format,
• Grout pattern,
• Edge breakage,
• Surface characteristics,
• visible damage,
• Batch variations,
• obvious material properties.

Claims regarding properties that would have been recognizable prior to installation cannot generally be accepted after installation has been completed.

17.3 Installation in accordance with recognized technical standards

Installation must be carried out exclusively in accordance with recognized technical standards and the respective manufacturer’s specifications for the building materials used.

These include, in particular:

• proper substrate preparation,
• suitable adhesives,
• suitable grouting materials,
• Compliance with processing times,
• Compliance with drying times,
• proper expansion joints,
• Suitable substrate conditions.

We assume no liability for damages resulting from improper installation.

17.4 Natural Product and Handcrafted Item

Many of our SKUs are composed entirely or partially of natural raw materials or are produced using artisanal techniques.

Natural variations regarding:

• Color,
• Grain,
• Structure,
• Surface appearance,
• Inclusions,
• Shades,

are part of the material’s typical appearance.

These characteristics do not constitute a defect.

17.5 Transport damage to individual tiles

Despite careful packaging, minor damage to individual mosaic tiles may occur during transport.

Since mosaics consist of a large number of individual stones, minor transport damage cannot be completely avoided for technical reasons.

These are remedied within the scope of standard installation work by replacing individual tiles.

This does not constitute a material defect.

Should the damage exceed the usual extent, please notify us promptly and provide clear photographs.

17.6 Goodwill Policy

Even though many of the described properties are technically determined and standard in the industry, we always strive for a customer-friendly and fair solution.

We review complaints on a case-by-case basis.

In the event of justified complaints, we will, where possible:

• Supply replacement material,
• replace individual tiles,
• offer a reasonable goodwill solution.

However, there is no entitlement to a specific goodwill gesture.

17.7 Storage

Until installation, the materials must be stored in a dry, frost-free location and protected from direct sunlight.

Damage caused by improper storage does not constitute a warranty claim.

17.8 Reorders

Reorders may differ from previous deliveries due to variations in production batches.

This applies in particular to:

• Color,
• Structure,
• Surface appearance,
• Stone format,
• Material thickness,
• mesh backing,
• Gloss level.

We therefore generally recommend ordering a sufficient total quantity, including reserve and repair materials.

17.9 Use of Offcuts

Offcuts and individual replacement tiles should be retained whenever possible.

These are particularly suitable for:

• subsequent repairs,
• Replacement of individual tiles,
• Edge areas,
• Excerpts,
• Adjustment work.

17.10 Final Provisions

The properties described correspond to the current state of the art as well as the industry-standard installation rules for mosaics and tiles.

The purpose of these notes is to enable professional installation and to transparently present typical material properties.

When installed properly, the material- and production-related properties described herein do not impair either the suitability for use or the overall visual appearance of the finished surface.

We expressly recommend:

• a careful inspection prior to installation,
• a dry layout,
• sufficient waste,
• the use of suitable adhesive and grout materials,
• Installation by qualified professionals.

By following these instructions, most subsequent customer complaints can be avoided and high-quality results can be achieved in the long term.

18. Severability Clause

Should individual provisions of these notes be or become invalid in whole or in part, the validity of the remaining provisions remains unaffected.

The consumer’s statutory warranty rights remain unaffected, unless legally permissible restrictions or specifications regarding the standard material and product properties are described.

These notes are intended to describe the standard properties of mosaics, tiles, and comparable products, as well as to explain recognized installation guidelines, and do not constitute a restriction of mandatory statutory consumer rights.