Home › Lumber treatment › Impregnation Plants › The risk classes › The five class risk established on the basis of the wood humidity

The five class risk established on the basis of the wood humidity

RISK CLASS
EXPOSURE CONDITIONS
EXPOSURE TO HUMIDITY
DISTRIBUTION OF BIOLOGICAL AGENTS
 PROTECTIVE MEASURES TYPE OF PROTECTION
Funghi Insetti Termiti Organismi Marini
1 Wood for indoors in dry environment.Panelling and finishing. None - Present Locally present - Treatment optional depending on the fact whether its cost is not more than repair work or treatment. Surface depth:from 1 to 3 mm
2 Wood for structural work used in closed environment.Wood with risk of humidity. Occasional Present Present Locally present - Preventive treatment advisable, especially in the case of difficult and expensive repairs. Inclusive from depthfrom 1 to 3 mm.
3 Wood exposed to periods of humidity and dryness, no contact with the ground. Frequent Present Present Locally present - Preventive treatment Surface, minimum 3 mm depth65% alburnum.
4 Wood in contact with permanent humidity source (Wood humidity>20%). Wood for indoors/ outdoors. Permanent Present Present Locally present - Preventive Treatment and suitable construction measures. Average depth 3-6 mm.100% alburnum.
5 Wood in permanent contact with salt water. The humidity level of the wood is always over 20%. The part immersed attacked by marine invertebrates, part exposed to air risk class 4. Permanent Present Present Locally present Present Preventive Treatment with salts soluble in water plus suitable construction measures. Deep; minimum 6 mm100% alburnum

 

WOOD TYPES NATURAL DURABIITY PROPRTIES

N Not resistant

   A Alburnum

R Average resistance

   LS Healthy wood (duramen)

MR Very resistant

    

IMPREGNABILITY

No impr. Not possible
Low imp Low
Aver. Impr Average
Very impr. High

 

FUNGI

TERMITES

WOODWORM

LYCTUS

LONGHORN

 

  
 

A

LS

A

LS

A

LS

A

LS

A

LS

A

LS

RESINOUS WOODS

 

 

 

 

 

 

 

 

 

 

 

 

Douglas Fir

R

MR

N

N

N

MR

MR

MR

N

MR

Low impr.

Not impr.

Épicéa

N

N

N

N

N

N

MR

MR

N

N

Low impr.

Not impr.

Hemlock

N

N

N

N

N

N

MR

MR

N

N

Aver. Impr.

Not impr.

Larice

R

MR

N

N

N

MR

MR

MR

N

MR

Aver. Impr.

Not impr.

Austrian Black pine

N

R

N

R

N

MR

MR

MR

N

MR

High impr.

Not impr.

Maritime Pine

N

R

N

R

N

MR

MR

MR

N

MR

High impr.

Not impr.

Silvestre Pine

N

R

N

R

N

MR

MR

MR

N

MR

High impr.

Not impr.

Spruce

N

N

N

N

N

N

MR

MR

N

N

Aver. Impr.

Not impr.

Red Cedar

MR

MR

N

N

N

MR

MR

MR

N

MR

High impr.

Not impr.

Hardwood
(TEMPERATE CLIMATES)

                        

Chestnut

R

MR

N

R

N

MR

N

MR

MR

MR

High impr.

Not impr.

Oak

N

MR

N

N

N

MR

N

MR

MR

MR

High impr.

Not impr.

Ash

N

N

N

N

N

N

N

MR

MR

MR

Aver. Impr.

Not impr.

Beech

N

N

N

N

N

N

MR

MR

MR

MR

High impr.

High impr.

Elm

R

R

N

N

N

MR

N

MR

MR

MR

Aver. Impr.

Not impr.

Popular

N

N

N

N

N

N

MR

MR

MR

MR

High impr.

High impr.

Walnut

N

MR

N

N

N

N

MR

MR

MR

MR

High impr.

Low impr.

Hardwood
(TROPICAL CLIMATES)

                        

Mahogany

N

R

N

N

 At present the opinion is that tropical hardwood can resist attacks from woodworm.

N

MR

MR

MR

High impr.

Not impr.

Afrormosia

R

MR

  

MR

N

MR

MR

MR

High impr.

Not impr.

Azobé

R

MR

R

MR

N

MR

MR

MR

Aver. Impr.

Low impr.

Balsam

N

N

N

N

MR

      

Low impr.

Low impr.

Ilomba

N

N

N

N

N

N

MR

MR

High impr.

High impr.

Iroko

N

MR

N

MR

N

MR

MR

MR

High impr.

Aver. Impr.

Samba

N

N

N

N

N

N

MR

MR

High impr.

Aver. Impr.