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

1. General Note on the Nature of the Product

Mosaic is a handcrafted and, in part, 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 signs of authenticity and the manufacturing process and do not constitute a defect.

Production takes place in batches. As a result, technical differences may arise between individual shipments. Material properties, firing processes, and raw materials can cause minor variations in color, surface, and texture.

2. Batch Variability and Reorders

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

Important Notice

We therefore recommend ordering a sufficient surplus quantity, including waste and replacement material, with your initial order. This is the only way to avoid subsequent color or batch variations when placing repeat orders.

3. Color, Luster, 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 Considerations for 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, the viewing angle, the substrate, and the type of installation.
• Differences in gloss level or slight metallic effects are also inherent to the material.

These characteristics do not constitute grounds for a complaint.

4. Production-Related Variations and Tolerances

Depending on the material, size, and manufacturing process, the following tolerances are technically unavoidable:

• Dimensional deviations in mosaic sheets (e.g., 300 × 300 mm ± up to approximately 3%),
• minor variations in stone size,
• Differences in material thickness,
• slightly varying joint widths,
• varying 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 variations 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 typically replaced by qualified personnel during installation or are no longer visible after grouting.

The assessment is conducted 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

Minor chipping at 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 size of the mosaic tile, there are between approximately 100 and 1,000 individual mosaic tiles per square meter.

It is technically and economically impractical to deliver every single tile free of defects.

It is rare for mosaic shipments to arrive 100% free of defects. In fact, it is rather the exception for there to be 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 cartons 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 imperfections 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 considered standard product characteristics.

6. Industry-Standard Tolerances and Quality Standards

It is in line with 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, as a general rule, 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.

Dimensional and surface variations may occur 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 area may exhibit minor visual characteristics such as small chips, chipped edges, or irregularities.

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

The assessment is conducted 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 mat 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 tiles,
• missing tiles,
• improperly installed tiles,
• Foreign objects,
• Damage,
• Color variations,
• Surface defects,
• Mat size and number of tiles per mat

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

The mat is then installed.

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

A dry layout prior to final installation is strongly recommended.

In particular, the following should be checked:

• Color gradation,
• Sample image,
• Grout pattern,
• Differences in size,
• Variations between batches,
• Overall visual effect.

Any noticeable deviations must be assessed prior to installation.

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

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

Installation despite recognizable defects generally precludes 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 due to stresses typical of the material, or previously unnoticed damage may become visible.

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,
• improperly installed tiles,
• visually objectionable tiles,
• Foreign objects,
• Damage during transport.

B) Removing Damaged Tiles

Damaged, missing, or visually objectionable tiles should be removed from the mat before installation.

This constitutes 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 will remain blank for the time being.

D) Replacement of Individual Tiles

Any gaps are then filled with suitable pieces from offcuts or available replacement material.

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

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

Alternatively, a suitable piece 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.

The replacement of individual tiles is considered a standard installation procedure and does not constitute an extraordinary amount of work.

9. Offcuts, Replacement Materials, and Industry-Standard Tolerances

It is common practice and recommended by specialized contractors to allow for a sufficient amount of waste when working with mosaics, tiles, borders, and similar products.

These include, among others:

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

A proportion of approximately 5% in offcuts or replacement material is considered the standard practice in the industry.

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 shipments and, where complaints are justified, provide a replacement free of charge whenever possible.

We generally recommend ordering approximately 5% more than the required quantity as a reserve and for replacement.

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

Each mosaic tile is unique.

Slight variations in:

• Tile size,
• 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.

Particularly 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 appearances,
• Shading,
• 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

Mosaics must be installed in accordance with recognized industry standards.

Only suitable substrates, adhesives, grout 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 installed despite visible defects is deemed to have been accepted with respect to these characteristics.

Warranty claims based on characteristics or deviations visible prior to installation generally cannot be asserted once the product has been installed.

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

12. Installation – Mesh, Film, and Special Adhesive Applications

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

In particular, with transparent glass mosaics or specialty 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 reactive 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 caused by unsuitable materials or improper installation does not constitute a warranty claim.

As a general rule, the manufacturer’s instructions for the construction chemicals used and the recognized rules of the trade must be followed.

13. Special Notes for Swimming Pool Mosaics

For swimming pools, spa facilities, water basins, and other permanent underwater areas, only materials suitable for these purposes 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,
• lower risk of voids,
• lower risk of leaks,
• better visual results.

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

With transparent material, the mesh may be visible.

This effect does not occur with paper-backed mosaics.

The substrate must always:

• load-bearing,
• clean,
• dry,
• that is,
• 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 provided solely for general guidance regarding:

• Color,
• Material,
• Surface,
• Structure,
• Texture.

Samples are typically supplied in small sizes.

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

In particular, differences may occur in:

• Color shade,
• Shading,
• Gloss level,
• Tile size,
• Surface texture.

This does not constitute a defect.

Samples are generally non-returnable.

We recommend carefully examining samples before placing a large order.

15. Summary – What Does Not Constitute a Defect?

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

Material and Batch

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

Dimensions

• minor dimensional deviations,
• different tile sizes,
• varying material thicknesses,
• varying joint widths,
• Dimensional deviations in the mats.

Surface

• Edge chipping,
• minor chips,
• fine surface scratches,
• minor scratches,
• minor surface irregularities,
• Production-related variations in shape.

Individual tiles

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

Visual Characteristics

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

Installation

• Replacement of individual tiles,
• Use of replacement tiles from offcuts,
• Stress cracks in individual tiles after installation,
• Minor damage that can be repaired as part of standard installation work.

16. Final Notes

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

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 any obvious defects, damage, or deviations.

Once installation begins—in particular through cutting, bonding, or grouting—the material is deemed to have been inspected and accepted with regard to its visible characteristics.

Obvious characteristics or discernible deviations that could have been identified prior to installation generally cannot be the subject of a claim once the product has been installed.

Installation must be carried out in accordance with recognized technical standards and the manufacturer’s instructions 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 characteristics described are typical features of mosaics and, when installed properly, do not affect the suitability for use or the overall visual appearance of the finished surface.

The product images used in the online store are intended to illustrate the respective item. Due to batch-related variations, changes in the manufacturing process, and adjustments made by our suppliers, the actual appearance of the delivered goods may differ from older product images. This applies in particular to the arrangement, layout, number, and positioning of the individual mosaic tiles on a mat, as well as to joint widths and joint patterns. The product characteristics expressly stated in the respective product description—in particular, material, tile size, and mat dimensions—are decisive for the quality of the ordered item. A specific number of individual mosaic tiles per mat is considered agreed upon only if this is explicitly stated as a product characteristic in the product description. Deviations in a product image regarding the number or arrangement of the individual mosaic tiles therefore do not in and of themselves constitute a deviation from the agreed-upon quality, provided that the explicitly stated product characteristics of the ordered item are met. The buyer’s statutory warranty rights remain unaffected by this.
 

17. Legal Notices, Warranty, and Installation Guidelines

17.1 Obligation of the Buyer and Installer to Inspect the Goods

Both the purchaser 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,
• Characteristics,
• visible damage,
• Damage during transport,
• obvious material defects.

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

Any identified defects must be reported before installation begins.

17.2 Installation is deemed acceptance of visible characteristics

Upon commencement of installation, in particular through

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

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

These include, in particular:

• Color,
• Shade,
• Surface texture,
• Gloss level,
• Tile size,
• Grout pattern,
• Edge chipping,
• Surface characteristics,
• visible damage,
• Variations between batches,
• obvious material properties.

Claims regarding characteristics that would have been recognizable prior to installation cannot, as a general rule, 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 instructions for the building materials used.

These include, in particular:

• Proper substrate preparation,
• suitable adhesives,
• suitable grout materials,
• Compliance with installation times,
• Compliance with drying times,
• properly installed expansion joints,
• Suitable substrate conditions.

We assume no liability for damages resulting from improper installation.

17.4 Natural Products and Handcrafted Goods

Many of our products consist entirely or partially of natural raw materials or are manufactured using artisanal production methods.

Naturally occurring variations with regard to:

• 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 pieces, minor damage during transport cannot be completely avoided for technical reasons.

These issues are resolved within the scope of standard installation work by replacing individual pieces.

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 characteristics described are technically determined and standard in the industry, we always strive to find 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

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

This applies in particular to:

• Color shade,
• Structure,
• Surface appearance,
• Tile size,
• 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 saved whenever possible.

These are particularly suitable for:

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

17.10 Final Provisions

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

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

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

We strongly recommend:

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

Following these guidelines will help prevent most future complaints and ensure long-lasting, high-quality results.

18. Severability Clause

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

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

These notes are intended to describe the typical characteristics of mosaics, tiles, and similar products, as well as to explain recognized installation guidelines, and do not constitute a limitation of mandatory statutory consumer rights.