"Standard" quality is recommended for those areas where economic efficiency has priority. It is ideal for making stairs, doors, long elements, etc. 1-2 healthy knots, end cracks as wide as the width of the piece and mirrors are accepted.
This quality accepts sapwood, multiple even unhealthy knots, cracks on the entire surface of the timber. Insect holes and rot are not accepted. Density 700 - 750 kg / m3.