LVL Handbook EUROPE

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5. STRUCTURAL DESIGN OF CONNECTIONS
The characteristic block shear capacity of a timber member is
calculated using the equation:
F_(bt,k)=L_(net,t)∙t_1∙k_bt∙f_(t,0,k) (5.10)
where
Lnet,t is according to equation (5.8)
kbt is 1,50 for solid wood and glued laminated timber and
1,25 for LVL; and
t1 is the thickness of the timber member (t1 ≤ 2 tef).
The characteristic block shear capacity of a LVL-C member is
calculated using the equation:
F_(bt,k)=max{█(L_(net,t)∙t_1∙f_(t,0,k)+0,7∙L_
(v,k)@L_(net,t)∙t_1∙k_bt∙f_(t,0,k) )┤ (5.11)
L_(net,v)=2∙(a_3+(n_1-1)∙(a_1-D)) (5.12)
fv,k is edgewise shear strength, for LVL 36 C
fv,0,edge,k = 4,5 N/mm2
LVL suppliers have also more advanced instructions in their
technical documentation.
5.4 NAILED CONNECTIONS
Instructions for nailed connections are presented in Section 8.3
of Eurocode 5. In addition to those instructions, the following
instructions shall also be taken into account:
• LVL members shall be predrilled when the diameter d of the
nail exceeds 6 mm
• For nails with diameters up to 8 mm arranged perpendic-
ular to the grain, the following characteristic embedment
strengths apply 32:
• without predrilled holes in softwood LVL or GLVL:
f_(h,k)=(0,082 ∙ ρ_(k )∙ d^(-0,3))/(k_
• sin^2 β) [N/mm2] (5.13)
• with predrilled holes in softwood LVL or GLVL
f_(h,k)=(0,082 ∙ (1 - 0,01d) ∙ ρ_k)/(k_C ∙〖
(5.14)
where
ρk is the characteristic density, in kg/m³;
β is the angle between nail axis and wide face; and
d is the nail diameter, in mm.
k_C {█(1 for LVL-P and GLVL-P@min{█
for LVL-C and GLVL-C┤ )┤ (5.15)
• To prevent splitting failure mode, for one row of n nails paral-
lel to the grain, unless the nails of that row are staggered per-
pendicular to grain by at least 1d, the load-carrying capac-
ity parallel to the grain (see EC5, clause 8.1.2(4)) should be
calculated using the effective number of fasteners nef = nkef .
kef in Table 8.1 of Eurocode 5 applies to LVL-P wide face.
For LVL-C wide face kef = 1 and for LVL or GLVL edge face:
k_ef=min{█(1@1-0,03(20-a_1/d) )┤ (5.16)
• For smooth nails in predrilled holes in the edge face of LVL
or GLVL the pointside penetration length should be at least
12d
• LVL member thicknesses:
• LVL-P or GLVL-P with nails in the wide face should be
pre-drilled when the thickness of the timber members is
smaller than
t=max{█(7d@(13d-30) ρ_k/400)┤ (5.17)
where
t is the minimum thickness of timber member to avoid
pre-drilling [mm]
ρk is the characteristic timber density [kg/m³]; and
d is the nail diameter [mm].
• Expression (5.17) may be disregarded for nails in the wide
face of LVL-C or GLVL-C.
• LVL or GLVL with nails in the edge face should be pre-
drilled when the thickness of the member in nailing di-
rection is smaller than
t=max{█(14d@(13d-30)ρ_k/200)┤ (5.18)
• Expression (5.17) may be replaced by expression (5.18) for
edge distances a4 ≥ 14d
• In axially loaded nail connections for smooth nails without
predrilled holes and with a pointside penetration of at least
12d, the characteristic strength values of the withdrawal fax,k
and pull-through fhead,k strengths [N/mm2] should be found
from the following expressions 32 :
fax,k = 20 ∙ 10 -6 ∙ ρk 2 for in the wide face of LVL
and GLVL (5.19)
fax,k = 0,32 ∙ d + 0,8 for in the edge face of LVL
and GLVL with ρ k ≥ 480kg/m3 (5.20)
fhead,k = 70 ∙ 10 -6 ∙ ρk 2 (5.21)
where ρk is the characteristic density kg/m 3. However,
smooth nails shall not be used to resist permanent or long-
term axial loading.
ft,0,k is the tension strength of the timber member: 35 N/mm2 for LVL 48 P and 19
N/mm2 for LVL 36 C;
fv,0,k is the shear strength of the timber member: fv,0,flat,k is 2.3 N/mm2 for LVL 48 P
and 1.3 N/mm2 for LVL 36 C in flatwise connections;
Rk is the characteristic load-carrying capacity per shear plane per fastener; and
d is the fastener diameter.
The characteristic block shear capacity of a timber member is calculated using the equation:
bt,k = net,t ∙ 1 ∙ bt ∙ t,0,k (5.10)
where
net,t is according to equation (5.8) 
„– ‹• 1,50, for solid wood and glued laminated timber and 1,25, for LVL; and
t1 is the thickness of the timber member (t1 ≤2 tef).
The characteristic block shear capacity of a LVL-C member is calculated using the equation:
bt,k = max { net,t ∙ 1 ∙ t,0,k + 0,7 ∙ net,v ∙ 1 ∙ v,k
net,t ∙ 1 ∙ bt ∙ t,0,k (5.11)
net,v = 2 ∙ ( 3 + ( 1 − 1) ∙ ( 1 − )) (5.12)
fv,k is edgewise shear strength, for LVL 36 C fv,0,edge,k = 4,5 N/mm2
LVL suppliers have also more advanced instructions in their technical documentation.
5.4 Nailed connections
Instructions for nailed connections are presented in Section 8.3 of Eurocode 5. In addition to
those instructions, the following instructions shall also be taken into account:
• LVL members shall be predrilled when the diameter d of the nail exceeds 6 mm
• For nails with diameters up to 8 mm arranged perpendicular to the grain, the following
characteristic embedment strengths apply 32:
o without predrilled holes in softwood LVL r GLVL:
h,k = 0,082 ∙ k ∙ −0,3
C ∙ cos2 + sin2 [N/mm2] (5.13)
o with predrilled holes in softwood LVL or GLVL
h,k = 0,082 ∙ (1 − 0,01 ) ∙ k
C ∙ cos 2 + sin2 [N/mm2] (5.14)
Where
a3 is the fastener end distance;
D is the hole diameter;
ft,0,k is the tension strength of the timber member: 35 N/mm2 for LVL 48 P and 19
N/mm2 for LVL 36 C;
fv,0,k is the shear strength of the timber member: fv,0,flat,k is 2.3 N/mm2 for LVL 48 P
and 1.3 N/mm2 for LVL 36 C in flatwise connections;
Rk is the characteristic load-carrying capacity per shear plane per fastener; and
d is he fastener diameter.
The characteris ic block shear capacity of a timber member is calculated using the equation:
bt,k = net,t ∙ 1 ∙ bt ∙ t,0,k (5.10)
where
net,t is according to equation (5.8) 
„– ‹• 1,50, for solid wood and glued laminated timber and 1,25, for LVL; and
t1 is he thi kness of the timber member (t1 ≤2 tef).
The characteristic block shear capacity of a LVL-C member is calculated using the equation:
bt,k = max { net,t ∙ 1 ∙ t,0,k + 0,7 ∙ net,v ∙ 1 ∙ v,k
net,t ∙ 1 ∙ bt ∙ t,0,k (5.11)
net,v = 2 ∙ ( 3 + ( 1 − 1) ∙ ( 1 − )) (5.12)
fv,k is edgewise sh ar stre gth, for LVL 36 C fv,0,edge,k = 4,5 N/mm2
LVL suppliers have also more advanced instructions in their technical documentation.
5.4 Nailed conn tions
Instructions for nailed connections are presented in Section 8.3 of Eurocode 5. In addition to
those instruction , t e following nstructio s shall also be taken i to account:
• LVL members shall be predrilled when the diameter d of the nail e ce ds 6 mm
• For nails with diameters up to 8 mm arranged perpendicular to the grain, the following
characteristic embedment strengths apply 32:
o without predrilled holes in softwood LVL or GLVL:
h,k = 0,082 ∙ k ∙ −0,3
C ∙ cos2 + sin2 [N/mm2] (5.13)
o with predrilled holes in softwood LVL or GLVL
h,k = 0,082 ∙ (1 − 0,01 ) ∙ k
C ∙ cos 2 + sin2 [N/mm2] (5.14)
Where
fh,0,k is the embedment st ength according to subsection 5.5.1 or 5.6;
n 1 is the numb r f fasten rs in rows parallel to the grain;
n 2 is the number of fasten r rows p rpendicular to the grain;
a 1 is the f stener spacing parallel to the gr in;
a 2 is the fa ener sp ing perpen i ular to the grain;
a 3 is the fastener end distance;
D is th hole diameter;
ft,0,k is the tension strength of th timber me : 35 N/mm2 for LVL 48 P and 19
N/mm2 for LVL 36 C;
fv,0,k is the shear strength of the timber member: fv,0,flat,k is 2.3 N/mm2 for LVL 48 P
and 1.3 N/mm2 for LVL 36 C in flatwise connections;
R k is the characteristic load-carrying capacity per shear plane per fastener; and
d is the fa tener diameter.
The characteristic block shear capacity of a timber member is calculated using the equation:
bt,k = net,t ∙ 1 ∙ bt ∙ t,0,k (5.10)
wherenet,t is according to equation (5.8) 
„– is 1,50 for solid wood and glued laminated timber and 1,25 for LVL; and
t1 is the thickness of the timber member (t1 ≤2 tef ).
The characteristic block shear capacity of a LVL-C member is calculated using the equation:
bt,k = max { net,t ∙ 1 ∙ t,0,k + 0,7 ∙ net,v ∙ 1 ∙ v,k
net,t ∙ 1 ∙ bt ∙ t,0,k (5.11)
net,v = 2 ∙ ( 3 + ( 1 − 1) ∙ ( 1 − )) (5.12)
fv,k is edgewise shear strength, for LVL 36 C fv,0,edge,k = 4,5 N/mm2
LVL suppliers have also more advanced instructions in their technical documentation.
5.4 Nailed connections
Instructions for nailed connections are presented in Section 8.3 of Eurocode 5. In addition to
those instructions, the following instructions hall also be taken into account:
• LVL members shall be predrilled when the dia eter d of the nail exceeds 6 mm
• For nails with diameters up to 8 mm arranged perpendicular to the grain, the following
characteristic embedment strengths apply 32:
o ri l s in softw od LVL or GLVL:
h,k = 0,082 ∙ k ∙ −0,3
C ∙ cos2 + sin2
[N/mm2] (5.13)
o wit predrilled holes in softwood LVL or GLVL
182 (255)
h,k = 0,082 ∙ (1 − 0,01 ) ∙ k
C ∙ cos2 + sin2
[N/mm 2] (5.14)
where
ρk is the characteristic density, in kg/m³
β is the angle between nail axis and wide face
d is the nail diameter, in mm
C { 1 or LVL − P and GLVL − Pmin {( −2)3 for LVL − C and GLVL − C (5.15)
• To prevent splitting failure mode, for one row of n nails parallel to the grain, unless the
nails of that row are staggered perpendicular to grain by at least 1 d, the load-carrying
capacity parallel to the grain (see EC5, clause 8.1.2(4)) should be calculated using the
effective number of fasteners nef = nkef. kef in Table 8.1 of Eurocode 5 applies to LVL-P
wide face. For LVL-C wide face k ef = 1 and for LVL or GLVL edge face:
(5.16)
182 (255)
ρk is the characteristic density, in kg/m³
β is t e ngle betw en nail axis and wide face
d is the nail diameter, in mm
C { 1 or LVL − P and GLVL − Pmin {( −2)3 for LVL − C and GLVL − C (5.15)
• To prevent splitting failure mode, for one row of n nails parallel to the grain, unless the
nails of that row re staggered perp ndicular to grain by at least 1d, the load-carrying
capaci y par ll l to th grain (se EC5, clause 8.1.2(4)) shoul be calculated using the
effective number of f sten rs nef , = nkef . kef in Table 8.1 of Eurocode 5 applies to LVL-P
wid face. For LVL-C wide face kef = 1 and for LVL or GLVL edge face:
(5.16)
ρk is the characteristic density, in kg/m³
β is the angle between nail axis and wide face
d is the nail diameter, in mm
C { 1 or LVL − P and GLVL − Pmin {( −2)3 for LVL − C and GLVL − C
• To prevent splitting failure mode, for one row of n nails parallel to th
nails of that row are staggered perpendicular to grain by at least 1d,
capacity parallel to the grain (see EC5, clause 8.1.2(4)) should be c
effective number of fasteners n ef, = nkef . kef in Table 8.1 of Eurocode
wide face. For LVL-C wide face kef = 1 and for LVL or GLVL edge fa
ef = min { 1
1 − 0,03(20 − 1/ )
• For smooth nails in predrilled holes in th edge face of LVL or GLVL
penetration leng h should be at least 12d
• LVL member thicknesses:
o LVL-P or GLVL-P with nails in the wide face should be pre-dr
thickness of the timber members is smaller than= max { 7 (13 − 30) k 400
where
t is the minimum thickness of timber member to avoid pr
ρk is the characteristic timber density [kg/m³]; and
d is the nail diameter [mm].
Expression (5.17) ay be disregarded for nails in the wide fa
GLVL-C.
o LVL or GLVL with nails in the edge face should be pre-drilled
of the member in nailing direction is smaller than= max { 14 (13 − 30) k 200
o Expression (5.17) may be replaced by expression (5.18) for
14d
• In axially loaded nail connections for smooth nails without predrilled
pointside penetration of at least 12d , the characteristic strength valu
fax,k and pull-through fhead,k strengths [N/mm2] should be found from t
expressions 32 :
ax,k = 20 ∙ 10−6 ∙ k2for in the wide face of LVL and GLVL
ax,k = 0,32 ∙ + 0,8 for in the edge face of LVL and GLVL
head,k = 70 ∙ 10−6 ∙ k2
where ρk is the characteristic density kg/m3. However, smooth nails
resist permanent or long-term axial loading.
The following information should be taken from the nail supplier’s Dop:
ρk is the characteristic density, in kg/m³
β is the angle between nail axis and wide face
d is the nail diameter, in mm
C { 1 or LVL − P and GLVL − Pmin {( −2)3 f r LVL − C and GLVL − C
• To prevent splitting failure mode, for one row of n nails parallel t the grai
nails o that row are staggered perpendicular to grain y at least 1d, the lo
capacity parallel t the grain (s e EC5, clause 8.1.2(4)) should be calcul t
effective number of fasteners n ef , = nkef . kef in Table 8.1 of Eurocode 5 ap
wide face. For LVL-C wide face kef = 1 and for LVL or GLVL edge face:
ef = min { 1
1 − 0,03(20 − 1/ )
• For smooth nails in predrilled holes in the edge face of LVL or GLVL the p
penetration length should be at least 12d
• LVL member thicknesses:
o LVL-P or GLVL-P with nails in the wide face should be pre-drilled
thickness of the timber members is smaller than= max { 7 (13 − 30) k
400
where
t is the minimum thickness of timber member to avoi pre-dril
ρk is the characteristic timber density [kg/m³]; and
d is the nail diameter [mm].
o Expression (5.17) may be disregarded for nails in the wide face of
GLVL-C.
LVL or G VL with nails in the edge face should be pre-drilled whe
of the member in nailing direction is smaller than= max { 14 (13 − 30) k 200
o Expression (5.17) may be replaced by expression (5.18) for edge
14d
• In axially loaded nail connections for smooth nails without predrilled holes
pointside penetration of at least 12d , the characteristic strength values of t
fax,k and pull-through fhead,k strengths [N/mm 2] should be found from the foll
expressions 32 :
ax,k = 20 ∙ 10 −6 ∙ k2for in the wide face of LVL and GLVL
ax,k = 0,32 ∙ + 0,8 f r in the edge face of LVL and GLVL with ρ
head,k = 70 ∙ 10−6 ∙ k2
where ρk is the characteristic density kg/m3. However, smooth nails shall
resist permane t long-term axial loading.
The following information should be taken from the nail supplier’s Dop:
ρk i t characteristic density, in kg/m³
β is the ngle between nail axis and wide face
d is the nail diameter, in mm
C { 1 or LVL − P and GLVL − Pmin {( −2)3 for LVL − C and GLVL − C
• To prevent splitting failure mod , for one row of n nails pa allel to the grai
nails of that row are stagg ed perpendicular to grain by at least 1 , the lo
capacity parallel to the grain (s e EC5, clause 8.1.2(4)) shoul b calculat
effective number of fasteners n ef , = nkef . kef in Table 8.1 of Eurocode 5 ap
wide face. For LVL-C wide face kef = 1 and for LVL or GLVL edge face:
ef = min { 1
1 − 0,03(20 − 1/ )
• For smooth nails in p edrilled holes in the edg face of LVL r GLVL the p
penetration le gth should b at least 12d
• LVL me ber thicknesses:
o LVL-P or GLVL-P with nails in the wide face should be pre-drilled
thickness of the timber members is smaller than= max { 7 (13 − 30) k
400
where
t is the minimum thickness of timber member to avoid pre-dril
ρk is the charact istic timber density [kg/m³]; and
d is the nail diameter [mm].
o Expression (5.17) may be disregarded for nails in the wide face of
GLVL-C.
o LVL or GLVL with nails in the edg face should be pre-drilled whe
of he me ber in nailing direction is smaller than= max { 14 (13 − 30) k 200
o xpre sion (5.17) may be replaced by expression (5.18) for edge
14d
• In axially loaded nail connections for smooth nails without predrilled holes
pointside penetration of at least 12d , the characteristic strength values of t
fax,k and pull-through fhead,k strengths [N/mm 2] should be found from the foll
expressions 32 :
ax,k = 20 ∙ 10 −6 ∙ k2for in the wide face of LVL and GLVL
ax,k = 0,32 ∙ + 0,8 for in the edg face of LVL and GLVL with ρ
head,k = 70 ∙ 10−6 ∙ k2
where ρk is the characteristic density kg/m3. However, smooth nails shall
resist permanent or long-term axial loading.
The follo ing information should be taken from the nail supplier’s Dop:
152 LVL Handbook Europe