New and Old Fire Classes

Fire retardant wood can achieve higher standards in regard to fire resistance requirements than ordinary wood. Euro Class B and C in the new European system or surface class I and II in the old Swedish system can be achieved, see table. Fire class depends primarily on the amount of fire retardant. Plain wood normally amounts to Euro Class D or former Swedish surface class III.

 

Fire classes are based on testing in accordance with the new European method known as SBI, Single Burning Item or former Nordic method NT Fire 004 (the so called “Box Method” or lådmetoden). In the European system there are additional fire classifications for smoke s1, s2 or s3 and for burning droplets d0, d1 or d2.

 

The European classifications will gradually completely replace earlier national classifications. Thus removing a trade barrier. 

Fire Classes for Wood Products 

Product

Euro Class

 EN 13501-1

Former Swedish Surface Class 

Untreated Wood

D-s2, d0 1)

III

 

Fire Retardant Treated Wood 

B or C

s1, s2 or s3 2)

d0, d1 or d2 3)

I or II

1) Additional requirements for minimum thickness and density and assembly will be added, refer to Trätek  SP Kontenta 0311042.

2) European smoke class

3) European droplet class

 

European Classes for Construction Products (Except Floor Coverings)

Euro Class

Former Nordic Surface Classes

Typiska produkter

DK

FI

NO

SE

A1

NC

NC

In1/Ut1

NC

Stone, concrete

A2-s1,d0

NC

NC

In1/Ut1

NC

Drywall (with thin paper), mineral wool

B-s1,d0

A

1/I

In1/Ut1

I

Fire retardant treated wood,

drywall (thick paper)

C-s2,d0

B

1/II, 1/-

In2/Ut2

II

Fire retardant wood, wallpaper on drywalls

D-s2,d0

B

2/-

In2/Ut2

III

Wood, wooden panels

E

U

U

U

U

Plastics

F

U

U

U

U

No requirements; not tested

NC = non-combustible; U = Without Classification 

 

Guidelines on how fire retardant treated wood fire should be tested and classified issued by EU NB-CPD and is available in the enclosed position papers.  NB CPD SH02 12 096 Fire test +classif of untreated +fire ret treated wood const prod

 

Other Fire Classes

Other fire classifications that may be relevant regarding fire retardant treated wood are:

European classification for linings, such as Class K110 or K210 in accordance with EN 14135, in combination with the European Classifications.

Approved cladding in accordance with SP Fire 105

.