Delivered grades

Delivered grades of WRC boards in comparison with the usual classification according to ČSN.

The classification of wood according to ČSN isn’t suitable for wood species such as WRC. Grades according to ČSN would be something like this: Grade “A“ would be “A clear“ and “B clear“, “grade B“ would be “C clear“ and “select knotty“, grade “C“ would be grade “knotty“ and “standard and better“.  

Due to the above-mentioned differences, we use our own classification system. We do this because our grade standards are higher than Canadian standards both in the permitted content of defects and in the permitted content of lower quality grades – usually up to 15% compared to Canadian standards.

Technical data:

The allowed difference in width of milling profiles is +/- 1 mm. Also, the length of ARA T&G standard grade can be shorter by up to 40 mm compared to the declared and charged lengths. The differences are caused by milling the tongue-and-groove on the short sides.

Occasionally we select colors or only vertical fibers based on a special order. Delivered grade of WRC boards.

 

CLEAR GRADES

Sauna boards

NLGA 200a
WCLIB 102-b

200a. Sauna boards Saunařská palubka – humidity up to 12%

Use in interiors and saunas.
This is the highest grade we offer – without knots and other defects of ordinary wood. May contain only defects in small quantities such as:

  • Cups – very small
  • Knotts – not allowed
  • Skips – very small on the back side
  • Torn or Raised Grain – few and in small quantities
  • Warp – very small

 

A Clear and btr.

NLGA 200b
WCLIB 102-c

 

 

200b. “A clear and better” Construction board – humidity 16%

This grade is similar to sauna paneling, but with less strict grading than the 200B.

It is the ideal grade for exterior cladding.

Grade characteristics are:

  • Checks – small
  • Cups – small
  • Sapwood – may appear
  • Skips – occasionally at the end of the boards
  • Grain – mix of vertical and tangential
  • Torn or Raised Grain – may occur in small quantities
  • Warp – small
  • Knots – 2 small overgrown knots up to 10mm or their equivalent are allowed.

 

B Clear

NLGA 200c
WCLIB 102-d

 

 

200c. “B clear and better” Construction board with overgrown knots

Although grade B clear contains a larger number of knots and other defects, it still provides high quality and utility for use in exterior cladding. However, its availability is limited because this grade is the end result of sorting other grades.

Grade characteristics are:

    • Checks – may occur
    • Cups – may occur
    • Pin Holes – may occur to a limited extent
    • Sapwood – may occur
    • Skips – may occur
    • Splits – short
    • Tongue – narrow, Groove – may be unplaned
    • Grain – not selected
    • Warp – medium
    • Knots – 4 small overgrown knots up to 10mm or their equivalent.

 

KNOTTY GRADES

Select Knotty

 

 

 

 

204a. “Select knotty” Construction board with overgrown knots.

Grade characteristics are:

  • Checks – may occur
  • Cups – may occur
  • Pin Holes – may occur in rare cases
  • Sapwood – may occur to a limited extent,
  • Skips – may occur on the back side
  • Splits – short to 5% of the length
  • Tongue – narrow, Groove – may be rough, uneven, rugged, not planed
  • Grain – not selected.
  • Warp – medium
  • Knots – overgrown knots, cracked and blackened knots may occur to a limited extent.