This is a USA harvested, milled and finished product (natural grade).
The milling tolerences are;
Natural/Rustic Grade: ≤0.025”
Please note, any visible gaps/overwood less than the maximum tolerances above are not considered defects and do not apply to the 5% defect/waste allowance based on the species guidelines. Pieces that exhibit gaps/overwood in excess of these tolerances should be culled at the time of installation. Installation constitutes acceptance. Only those visible gaps/overwood in excess of these tolerances apply to the 5% defect/waste allowance.
NOFMA/NWFA clearly state that due to the dimensional change due to exposure to environmental conditions, milling tolerances are only valid at the time of original milling at the factory. You cannot measure the width or thickness of a board after that time and compare to established milling tolerances. It is not a valid measurement.
For the purposes of determining acceptability at the time of installation (assuming proper acclimation under controlled conditions), the installer must use the tolerances for visible gapping/overwood. To do this, the product must be assembled tightly according to good installation practices (not less than 6” between the ends of adjacent boards, no two adjacent boards can be the same length, etc.). Assuming proper acclimation and good assembly/installation practices.
The finish process is propietary.
Thank you for your question.
Answered on 12/2/2011 by customer care 2