How to install brick cladding indoors according to NF DTU 52.2?

Discover in this comprehensive tutorial all the steps to successfully install stone facing tiles.

Reconstituted stone brick cladding is increasingly popular for interior design thanks to its authentic look and ease of installation. However, to achieve a durable result that meets professional standards, its installation must comply with the requirements of NF DTU 52.2, the standard for bonded wall and floor coverings.

Preparation of the substrate, layout, double gluing, installation, jointing and treatment of expansion joints: this technical guide, produced in partnership with Alkern, details all the essential steps to successfully install brick cladding indoors according to best practices.

1. Choose a cladding suitable for your project

The tutorial demonstrates the implementation of a brick facing in reconstituted stone, here the Arpège model from Alkern.

Its main characteristics are as follows:

• Variable length between 24 and 26 cm in order to reproduce the natural appearance of the brick
• height of 5,6 cm
• thickness of 2 cm
• Coordinated corner pieces to ensure consistent finishes

Employment areas

These wall coverings are intended for the interior walls of homes and buildings.

They can be used in most rooms, except for areas subject to water splashes or frequent cleaning, such as some bathrooms or kitchen backsplashes.

Recommended hardware

• Suitable adhesive mortar and jointing mortar
• Trowel and notched spatula
• Electric mixer (speed < 500 rpm)
• Spirit level or construction laser
• Non-marking white rubber mallet
• Angle grinder with diamond disc
• Horizontal support cleat
• Plastic cord (Ø 10 mm) for calibrating joints
• jointing bag (or jointing machine) and jointing iron
• Nylon brush (metal brush prohibited) and sponge
• Elastomeric sealant and adhesive tape (for expansion and perimeter joints)
• Mandatory PPE: Safety glasses, gloves and dust mask

2. Prepare and check the support

The quality of the substrate directly affects the durability of the facing.

Before any installation, it must be:

• clean
• healthy
• sec
• strong enough to support the weight of the coating

Check the type of support

Most common substrates are compatible with mortar-adhesive installation.

On the other hand, plaster surfaces or surfaces covered with a plaster coating require the application of a bonding primer or the use of a ready-to-use paste adhesive (without mixing with water).

Thorough dusting is essential before applying any glue.

Check the flatness

The NF DTU 52.2 standard imposes a maximum tolerance of:

5 mm under a 2-meter ruler.

When this value is exceeded, leveling or filling must be carried out before work begins.

3. Prepare the layout plan before installation

As with any wall covering, the layout plan allows you to anticipate cuts and obtain a balanced result.

Before you start:

• identify the angles and any lintels
• check the ground level
• Install a horizontal batten to begin laying the second row

This method guarantees perfect alignment even if the ground has slight irregularities.

Mix the tablets

Since the elements are intentionally nuanced, it is recommended to open several boxes simultaneously in order to mix the shades and obtain a natural look.

The cuts are made using an angle grinder equipped with a diamond disc.

Plan for the joints

For brick facings, the minimum spacing is 2 mm.

For a traditional finish, a joint width of 10 mm, both horizontally and vertically, is generally recommended.

4. Prepare the adhesive mortar

The adhesive mortar must be prepared according to the manufacturer's instructions.

The mixing is carried out with an electric mixer operating at slow speed (maximum 500 rpm) in order to preserve the performance of the product.

To ensure a consistent dosage, it is advisable to prepare a full bag.

Prepare the facings

Before installation, the back of each plate must be:

• brushed
• clawed if necessary
• carefully dusted

This preparation significantly improves the adhesion of the bond.

5. Apply a double layer of glue

Double gluing is essential for this type of cladding.

It consists of applying:

• a layer of mortar-adhesive on the substrate
• a thin layer on the reverse side of each tablet

The glue is spread over limited areas of 1 to 2 m² to avoid premature drying.

A suitable notched spatula allows you to obtain a consistent thickness.

Technical focus: why is double gluing essential?

Double gluing allows for:

• to ensure optimal contact between the pad and the support
• to limit the risks of detachment
• to remove the gaps under the facing
• to improve the mechanical resistance of the assembly

This technique is required to guarantee the durability of the coating.

6. Install the wall cladding

The installation begins with the corner pieces when the project includes them.

The first plates rest on the starting block.

Each element is then:

• adjusted with a white rubber mallet
• checked with a spirit level or laser

To maintain a constant width of the horizontal joints, a 10 mm plastic cord is unrolled on the horizontal bed.

For vertical joints, ensure that you maintain the same 10 mm spacing while crossing the rows.

7. Carry out the grouting

Grouting takes place after a minimum period of 24 hours.

After removing the cord:

• prepare the flexible/mechanizable jointing mortar suitable for wide joints
• generously fill the spaces between the plates
• Tighten the joint as soon as the mortar begins to harden.

The application can be performed using:

• of a joint pocket
• or a jointing machine

Excess material is gradually removed with a nylon brush or a slightly damp sponge.

The use of a wire brush is not recommended in order to avoid damaging the surface of the facing.

8. Respect expansion joints

Like any glued covering, the facing must be able to absorb the natural movements of the building.

NF DTU 52.2 specifies, in particular:

Expansion joints

They penetrate the entire thickness of the coating.

Their minimum width is 5 mm.

The maximum distances are:

• 10 meters between two vertical joints
• 6 meters between two horizontal joints

Peripheral joints

A flexible joint of at least 5 mm must be made:

• around the walls
• in the corners
• to the right of the joinery
• around pipeline crossings
• at the fixed points

These joints are filled with a suitable elastomeric sealant.

The key points

Safety box

Cutting and mixing operations require the use of personal protective equipment:

• protective glasses
• suitable gloves
• FFP2 or FFP3 respiratory mask required for work generating dust.

Mistakes to avoid

• Place the tiles on an uneven surface.
• Forget about double gluing
• Do not mix tablets from different cartons.
• Neglecting peripheral or expansion joints
• Apply the grout before the recommended drying time.
• Use a wire brush for cleaning

To remember

The success of an interior wall covering depends above all on rigorous preparation of the substrate and compliance with the requirements of NF DTU 52.2. Checking flatness, precise layout, double gluing, controlling joint widths and respecting expansion joints are all essential steps to guarantee the durability of the work.

By following these best practices, reconstituted stone facing tiles offer an aesthetic, durable finish that meets the requirements of building professionals.