Fire reaction class D for timber

Untreated wood

Untreated wood is wood that has not been preserved through impregnation, has not been thermally or chemically modified, and/or has not received any surface treatment such as oil, paint, or varnish, etc.

Any untreated wood is still eligible if it meets the following conditions:

Conditions for facade construction with untreated wood

1. Insulation, at least A2-s1,d0 with a min. density of 10 kg/m³ (for exemple mineral wool)
PIR and PUR don't have class A. In that case, it is necessary to add a panel with fire class A2-s1,d0.

2. Moisture barrier

3. Ventilated air cavity + attachment system (e.g. spruce or pine timber).

4. Closed facade cladding, placed horizontally or vertically:

With a profile:

flat: min. thickness of 18 mm is required or
ribbed: min. thickness of 18 mm and min. thickness of 12 mm on the thinnest part is required (on max 25% of the profile area)

In a type of wood with a min. average density of 390 kg/m³.

Any deviation from the above conditions must be tested.

Treated wood

Treated wood is wood that has been preserved through impregnation, thermally or chemically modified, and/or received a surface treatment such as oil, paint, or varnish, etc.

According to the new rules of August 20, 2024, the 'treated wood' must be tested to determine if the facade construction meets the required reaction to fire class. You can no longer simply rely on the CWFT table when choosing 'treated' wood products.

You can avoid these tests by treating the wood with a fire retardant.

Lemahieu Fire Protection offers a wide range of CE certified products. Lemahieu Fire Protection's fire-retardant treatment impregnates the wood under vacuum pressure with the fire retardant Burnblock^® and thus meets B-s1,d0 (better than D-s3,d1). The fire-retardant treatment can also be combined with a pre-weathering or color as a surface treatment.

Good news for ThermoWood^® from LDCwood^® (without fire-retardant treatment)

The thermally modified products of LDCwood^® ThermoWood^® fall under the category of 'treated' wood. However, we can offer solutions* (without surface treatment) that meet the reaction to fire class D-s3,d1 without fire retardant treatment.

*Tests and classification report WFRGent nr. 19763G

Conditions for facade construction with LDCwood® ThermoWood®

1. Substrate

Wood-based panels (class D-s2,d0 or better, minimum thickness of 10 mm, minimum density of 510 kg/m³) or
Non-combustible panels (class A2-s1,d0 or better, minimum thickness of 10 mm, minimum density of 510 kg/m³)

2. Moisture barrier

3. Ventilated air cavity with a min. thickness of 38 mm + attachment system (e.g. spruce or pine with a min. density of 450 kg/m³).

4. Closed facade cladding, placed horizontally or vertically:

Using a flat profile: min. thickness of 18 mm is required

In LDCwood^®ThermoWood^® spruce, pine, fraké, ash, red oak or radiata pine (without surface treatment).

Any deviation from the above wood species and conditions must be tested.

A rain screen (<1 mm) has no significant impact on the reaction to fire class of closed cladding.

Conditions for facade construction with LDCwood® ThermoWood®

1. Substrate

Wood-based panels (class D-s2,d0 or better, minimum thickness of 10 mm, minimum density of 510 kg/m³) or
Non-combustible panels (class A2-s1,d0 or better, minimum thickness of 10 mm, minimum density of 510 kg/m³)

2. Moisture barrier

3. Ventilated air cavity with a min. thickness of 38 mm + attachment system (e.g. spruce or pine with a min. density of 450 kg/m³).

4. Closed facade cladding, placed horizontally or vertically:

Using a flat profile: min. thickness of 18 mm is required

In LDCwood^®ThermoWood^® spruce, pine, fraké, ash, red oak or radiata pine (without surface treatment).

Any deviation from the above wood species and conditions must be tested.

A rain screen (<1 mm) has no significant impact on the reaction to fire class of closed cladding.

Certified products

Lemahieu Fire Protection offers a wide range of CE certified wood products.

Lemahieu Fire Protection's fire-retardant treatment impregnates the wood under vacuum pressure with the fire retardant Burnblock^® and thus meets B-s1,d0 (better than D-s3,d1). The fire-retardant treatment can also be combined with a pre-weathering or color as a surface treatment.

Timber import

Processing

Wood protection

Fire protection

Lempan

My facade must fulfil the requirements of reaction to fire class D-s3,d1

Untreated wood

Conditions for facade construction with untreated wood

Treated wood

Conditions for facade construction with LDCwood® ThermoWood®

Conditions for facade construction with LDCwood® ThermoWood®

Certified products

Reaction to fire class B-s3,d1 or C-s3,d1

Durability over time

Certified products

Want to know more?

Want to know more?

Cut from the right wood