THERMOWOOD Spruce Updated: March 2014

Thermo Spruce - March General Information Main end uses for Metsä ThermoWood ® are –Thermo-D: external cladding and decking –Thermo-S: internal cladding and sauna benches The heat treatment enables the use of Scandinavian Whitewood in areas such as external claddings without the need for a chemical preservatives However, the main share of Whitewood ThermoWood ® is treated as Thermo-S for internal claddings Whitewood ThermoWood ® is mainly used due to it’s appearance, thus visual quality is of high importance Main market for Whitewood ThermoWood ® is the Alps area (France, Switzerland, Italy) where Whitewood ThermoWood ® is used to “look old and traditional” Metsä ThermoWood® is more stable than untreated softwood. It is less able to absorb or lose moisture. This limits any potential for swelling, shrinkage or distortion ThermoWood® is sourced from well managed and sustainable forests

Thermo Spruce - March Size specification General dimensions 22 * 150 / 175 / 200 / 225 Thermo-S Raw material can also be 47mm (split at Kaskinen) 25 * 150 / 175 / 200 / 225 Thermo-S 38 * 175 / 200 / 225 Thermo-S Raw material can also be 63mm (split at Kaskinen) Special sizes for Velux Thermo-S: Treatment temperature 190 o C (mainly for indoor use) Thermo-D: Treatment temperature 212 o C (for both indoor and outdoor use)

Thermo Spruce - March General knot types Source: RT-kortti Sound knotDead knotBarkringed knotBlack knot Arris knotSplay knotSpike knotKnot cluster GENERAL KNOT SUM RULE: If the knot size is smaller than the table value, a greater number of knots is permitted. Total knot sum counted in mm (=number of knots * diameter) should not anyhow exceed.

Thermo Spruce - March –Total Thermo Spruce production: abt m3 (budget 2011) –Metsäwood Sawmills producing raw material for Thermo Spruce Vilppula Renko Svir Timber –Optimum rawmaterial moisture: 22% So a bit more than regular shipping dry Sawmills should try to get as near as possible: overkilning is a problem! –Normal set-ups: 22/25mm 4 ex log cutting from sound knotted logs 47/50/63mm 2e x log cutting from sound knotted logs –Normal grading for Thermowood is “sound knotted fifth”, where black knotted US and naturally VI & VII are graded away –Normal lengths requirements: m –Following rules are for inside use and knots sizes reflects from grading camera rules General information; sawmills/volume

Thermo Spruce - March Inside face sound knot INSIDE FACE SOUND KNOT RULES Size outReferenceAmount THICKNESSWIDTHof widthlength mm ALLX15050 % ALLX17550 % ALLX20050 % ALLX22550 % Addition to above: 2 maximum knots (+7 mm to normal knot size) allowed. Normally the sound knots on the face do not cause downgrading (if they are 100% intact)!

Thermo Spruce - March Spike knot Sound knot rules apply also to sound spike knots Formula for calculating spike knot square area: (D + d) / 6 D d

Thermo Spruce - March Splay knot Sound knot rules apply also to sound splay knots Formula for calculating splay knot square area: (D + d) / 3 D d

Thermo Spruce - March Inside face black and dead knot Black / Dead knot Knot rules black / dead knot INSIDE FACE DEAD/BLACK KNOT RULES Size outReferenceAmount THICKNESSWIDTHof widthlength mm ALLX15015 %20003 ALLX17515 %20003 ALLX20010 %20003 ALLX22510 %20003 Addition to above: 1 maximum knot (+5 mm to normal knot size) allowed The key point with black and dead knots is that there are no holes in the end product!

Thermo Spruce - March Inside face barkringed knot INSIDE FACE BARKRINGED KNOT RULES Size outReferenceAmount THICKNESSWIDTHof widthlength mm ALLX15015 %20002 ALLX17515 %20002 ALLX20010 %20002 ALLX22510 %20002 Addition to above: 1 maximum knot (+5 mm to normal knot size) allowed The key point with barkringed knots is that there are no holes in the end product!

Thermo Spruce - March Pin knot On the board: Pin knots = sound knots <10 mm and dead knots <8 mm are allowed and not counted to the total knot sum. Loose dead knots are not allowed because no holes are allowed in the end product!

Thermo Spruce - March Loose knot and hole Not allowed in the raw material nor end product! Loose knot in ThermoWood treated material Hole Loose knot

Thermo Spruce - March Edge and arris sound knot Sound Arris knot Sound edge knot EDGE SOUND KNOT RULES Size outReferenceAmount THICKNESSWIDTHof thicknesslength mm ALLX %20006 ALLX %20006 ALLX %20006 ALLX %20006 Normally the edge and arris sound knots do not cause downgrading (if they are 100% intact)!

Thermo Spruce - March Edge black and dead knot Dead black knot EDGE DEAD/BLACK KNOT RULES Size outReferenceAmount THICKNESSWIDTHof thicknesslength mm ALLX15045 %20003 ALLX17545 %20003 ALLX20045 %20003 ALLX22545 %20003 Addition to above: 1 maximum knot (+5 mm to normal knot size) allowed Knot must position minimum 3mm from inside face arris. Edge black and dead knots are not critical in the product, because most likely they will not be visible! min 3mm

Thermo Spruce - March Edge barkringed knot Barkringed knot EDGE BARKRINGED KNOT RULES Size outReferenceAmount THICKNESSWIDTHof thicknesslength mm ALLX15045 %20003 ALLX17545 %20003 ALLX20045 %20003 ALLX22545 %20003 Addition to above: 1 maximum knot (+5 mm to normal knot size) allowed Knot must position minimum 3mm from inside face arris. Edge barkringed knots are not critical in the product, because most likely they will not be visible!

Thermo Spruce - March Arris dead and black knot Dead and black knot B: max 60mm A: max 12 mm A B (inside face) 22/25mm max 12mm max 60mm 32mm max 12mmmax 60mm 38mm max 25mmmax 60mm 44-63mm arris rules not in use

Thermo Spruce - March Arris barkringed knot Barkringed knot B: max 30mm A: max 7 mm A B (inside face) 22/25mm max 7mm max 30mm 32mm max 7mmmax 30mm 38mm max 15mmmax 30mm 47-63mm arris rules not in use

Thermo Spruce - March Resin pocket Not allowed in principle, but very difficult to downgrade at Whitewood Sawmills.

Thermo Spruce - March Heartwood and heart Allowed, heartwood and heart are centre cut timber’s natural qualities.

Thermo Spruce - March Top rupture Not allowed in principle, but very difficult to downgrade at Whitewood Sawmills.

Thermo Spruce - March Shake Through and ring shake not allowed! OUTSIDE FACE SHAKE RULES Max.Max. widthMax. lengthEnd shake’s length %mm max. length mm 20 %25080 INSIDE FACE SHAKE RULES Max.Max. widthMax. lengthEnd shake’s length %mm max. length mm 20 %25080

Thermo Spruce - March Warp Cup Spring Bow WARP % out of timber widthReference BowSpringCupTwistlength 20mm15mm3 %25mm2000

Thermo Spruce - March Key points for Whitewood rawmaterial 1.Sound knots are not a downgrading factor 2.No holes (of any kind) 3.No black/dead knots, which are likely to cause holes in treatment and/or planing 4.No mechanical damages nor wane 5.No shakes, deformation, top rupture or other “VI defects” 6.Goods have to be in nominal measurements when delivered to KTC 7.Moisture content target 22 +/- 2 % for optimal treatment Optimal share of grades from ungraded logs: US abt. 30% (small black/dead knotted material) V/SF abt. 55% for Thermowood VI abt. 10% and VII (or VI dom) abt. 5% Pricing to Sawmill has to be tempting in order to do a special product ! Summary