Group 1, clay
Wall without a longitudinal joint: constructed with general-purpose mortar and with standard- format clay bricks having no more than 25% of formed voids or 20% frogs; Group 1 units. See Table A1.1(a) and Figure A1.1(a).
Table A1.1(a). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 bricks
¼ 0.85 K ¼ 0.50 (i.e. wall thickness ¼ brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-1 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 2.6 4.7 6.3 7.7 10.2 12.4 14.5 19.3 23.6 28.3 28.3
(ii) M6 2.4 3.8 5.1 6.2 8.3 10.1 11.8 15.7 19.2 23.0 23.0
(iii) M4 2.1 3.4 4.5 5.5 7.3 8.9 10.5 13.9 17.0 20.3 20.3
(iv) M2 1.7 2.8 3.7 4.5 5.9 7.3 8.5 11.3 13.8 16.5 16.5
Figure A1.1(a). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 bricks
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry, fk : N/mm 2 0 5 10 15 20 25 30 M12 M6 M4 M2 fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
Group 1, concrete
Wall without a longitudinal joint: constructed with general-purpose mortar and with standard- format concrete bricks having no more than 25% of formed voids or 20% frogs; Group 1 units. See Table A1.1(b) and Figure A1.1(b).
Table A1.1(b). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 bricks
¼ 0.85 K ¼ 0.55 (i.e. wall thickness ¼ brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-3 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 2.9 5.2 6.9 8.4 11.2 13.7 16.0 21.2 26.0 31.1 31.1
(ii) M6 2.6 4.2 5.6 6.8 9.1 11.1 13.0 17.3 21.1 25.3 25.3
(iii) M4 2.3 3.7 5.0 6.1 8.0 9.8 11.5 15.3 18.7 22.4 22.4
(iv) M2 1.9 3.0 4.0 4.9 6.5 8.0 9.3 12.4 15.2 18.2 18.2
Figure A1.1(b). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 bricks
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry, fk : N/mm 2 M12 M6 M4 M2 fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor 0 5 10 15 20 25 30 35
Group 1, calcium silicate
Wall without a longitudinal joint: constructed with general-purpose mortar and standard-format calcium silicate bricks having no more than 25% of formed voids or 20% frogs; Group 1 units. See Table A1.1(c) and Figure A1.1(c).
Table A1.1(c). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 calcium silicate bricks
¼ 0.85 K ¼ 0.50 (i.e. wall thickness ¼ brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-2 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 2.1 4.0 5.4 6.5 8.7 10.6 12.4 16.5 20.2 24.3 26.8
(ii) M6 2.0 3.3 4.3 5.3 7.1 8.6 10.1 13.4 16.4 19.7 21.8
(iii) M4 1.8 2.9 3.9 4.7 6.3 7.7 8.9 11.9 14.5 17.5 19.3
(iv) M2 1.4 2.4 3.1 3.8 5.1 6.2 7.3 9.7 11.8 14.2 15.7
Figure A1.1(c). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 calcium silicate bricks
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor 0 5 10 15 20 25 30 M12 M6 M4 M2
Group 2, clay
Wall without a longitudinal joint: constructed with general-purpose mortar and with standard- format clay bricks having more than 25% voids but no more than 55% of formed voids; Group 2 units. See Table A1.1(d) and Figure A1.1(d).
Table A1.1(d). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 bricks
¼ 0.85 K ¼ 0.40 (i.e. wall thickness ¼ brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-1 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 2.1 3.8 5.0 6.1 8.1 10.0 11.6 15.5 18.9 22.6 22.6
(ii) M6 1.9 3.1 4.1 5.0 6.6 8.1 9.4 12.5 15.3 18.4 18.4
(iii) M4 1.7 2.7 3.6 4.4 5.9 7.2 8.4 11.1 13.6 16.3 16.3
(iv) M2 1.4 2.2 2.9 3.6 4.8 5.8 6.8 9.0 11.0 13.2 13.2
Figure A1.1(d). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 bricks 0 5 10 15 20 25
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
Group 2, concrete
Wall without a longitudinal joint: constructed with general-purpose mortar and with standard- format concrete bricks having more than 25% voids but no more than 55% of formed voids; Group 2 units. See Table A1.1(e) and Figure A1.1(e).
Table A1.1(e). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 concrete bricks
¼ 0.85 K ¼ 0.52 (i.e. wall thickness ¼ brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-3 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 2.7 4.9 6.5 8.0 10.6 12.9 15.1 20.1 24.6 29.4 29.4
(ii) M6 2.5 4.0 5.3 6.5 8.6 10.5 12.3 16.3 20.0 23.9 23.9
(iii) M4 2.2 3.5 4.7 5.7 7.6 9.3 10.9 14.4 17.7 21.2 21.2
(iv) M2 1.8 2.9 3.8 4.7 6.2 7.6 8.8 11.7 14.4 17.2 17.2
Figure A1.1(e). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 concrete bricks 0 5 10 15 20 25 30
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
Group 2, calcium silicate
Wall without a longitudinal joint: constructed with general-purpose mortar and standard-format calcium silicate bricks having more than 25% voids but no more than 55% of formed voids; Group 2 units. See Table A1.1(f ) and Figure A1.1(f ).
Table A1.1(f). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 calcium silicate bricks
¼ 0.85 K ¼ 0.40 (i.e. wall thickness ¼ brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-2 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 1.6 3.2 4.3 5.2 7.0 8.5 10.0 13.2 16.2 19.4 21.5
(ii) M6 1.6 2.6 3.5 4.3 5.7 6.9 8.1 10.7 13.1 15.8 17.4
(iii) M4 1.4 2.3 3.1 3.8 5.0 6.1 7.2 9.5 11.6 14.0 15.4
(iv) M2 1.2 1.9 2.5 3.1 4.1 5.0 5.8 7.7 9.4 11.3 12.5
Figure A1.1(f). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 calcium silicate bricks
0 5 10 15 20 25 30
Mean compressive strength of unit: N/mm2
5 15 30 50 100 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
Group 3
Wall without a longitudinal joint. Group 3 clay units have not traditionally been used in the UK, so no values are available. Group 3 calcium silicate units are not used in Europe. Group 3 concrete units have not traditionally been used in the UK, so no values are available.
Group 4
Wall without a longitudinal joint. Group 4 clay units have not traditionally been used in the UK, so no values are available. Group 4 calcium silicate units are not used in Europe. Group 4 concrete units have not traditionally been used in the UK, so no values are available.
With longitudinal joints
Group 1, clay
Wall with a longitudinal joint: constructed with general-purpose mortar and with standard- format clay bricks having no more than 25% of formed voids or 20% frogs; Group 1 units. See Table A1.1(g) and Figure A1.1(g).
Table A1.1(g). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 bricks
¼ 0.85 K ¼ 0.8 0.50 (i.e. wall thickness > brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-1 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 2.1 3.8 5.0 6.1 8.1 10.0 11.6 15.5 18.9 22.6 22.6
(ii) M6 1.9 3.1 4.1 5.0 6.6 8.1 9.4 12.5 15.3 18.4 18.4
(iii) M4 1.7 2.7 3.6 4.4 5.9 7.2 8.4 11.1 13.6 16.3 16.3
(iv) M2 1.4 2.2 2.9 3.6 4.8 5.8 6.8 9.0 11.0 13.2 13.2
Figure A1.1(g). Wall without a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 bricks 0 5 10 15 20 25
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
Group 1, concrete
Wall with a longitudinal joint: constructed with general-purpose mortar and with standard- format concrete bricks having no more than 25% of formed voids or 20% frogs; Group 1 units. See Table A1.1(h) and Figure A1.1(h).
Table A1.1(h). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 concrete bricks
¼ 0.85 K ¼ 0.8 0.55 (i.e. wall thickness > brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-3 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 2.3 4.1 5.5 6.7 8.9 10.9 12.8 17.0 20.8 24.9 24.9
(ii) M6 2.1 3.4 4.5 5.5 7.3 8.9 10.4 13.8 16.9 20.2 20.2
(iii) M4 1.8 3.0 4.0 4.8 6.4 7.9 9.2 12.2 15.0 17.9 17.9
(iv) M2 1.5 2.4 3.2 3.9 5.2 6.4 7.5 9.9 12.1 14.5 14.5
Figure A1.1(h). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 concrete bricks 0 5 10 15 20 25 30
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
Group 1, calcium silicate
Wall with a longitudinal joint: constructed with general-purpose mortar and standard-format calcium silicate bricks having no more than 25% of formed voids or 20% frogs; Group 1 units. See Table A1.1(i) and Figure A1.1(i).
Table A1.1(i). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 calcium silicate bricks
¼ 0.85 K ¼ 0.50 (i.e. wall thickness ¼ brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-2 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 1.6 3.2 4.3 5.2 7.0 8.5 10.0 13.2 16.2 19.4 21.5
(ii) M6 1.6 2.6 3.5 4.3 5.7 6.9 8.1 10.7 13.1 15.8 17.4
(iii) M4 1.4 2.3 3.1 3.8 5.0 6.1 7.2 9.5 11.6 14.0 15.4
(iv) M2 1.2 1.9 2.5 3.1 4.1 5.0 5.8 7.7 9.4 11.3 12.5
Figure A1.1(i). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 1 calcium silicate bricks
0 5 10 15 20 25 30
Mean compressive strength of unit: N/mm2
5 15 30 50 100 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
Group 2, clay
Wall with a longitudinal joint: constructed with general-purpose mortar and with standard- format clay bricks having more than 25% voids but no more than 55% of formed voids; Group 2 units. See Table A1.1( j) and Figure A1.1( j).
Table A1.1(j). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 bricks
¼ 0.85 K ¼ 0.8 0.40 (i.e. wall thickness > brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-1 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 1.7 3.0 4.0 4.9 6.5 8.0 9.3 12.4 15.1 18.1 18.1
(ii) M6 1.5 2.5 3.3 4.0 5.3 6.5 7.6 10.0 12.3 14.7 14.7
(iii) M4 1.3 2.2 2.9 3.5 4.7 5.7 6.7 8.9 10.9 13.0 13.0
(iv) M2 1.1 1.8 2.3 2.9 3.8 4.7 5.4 7.2 8.8 10.6 10.6
Figure A1.1(j). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 bricks
0 5 10 15 20
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
Group 2, concrete
Wall with a longitudinal joint: constructed with general-purpose mortar and with standard- format concrete bricks having more than 25% voids but no more than 55% of formed voids; Group 2 units. See Table A1.1(k) and Figure A1.1(k).
Table A1.1(k). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 concrete bricks
¼ 0.85 K ¼ 0.8 0.52 (i.e. wall thickness > brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-3 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 2.2 3.9 5.2 6.4 8.5 10.3 12.1 16.1 19.7 23.5 23.5
(ii) M6 2.0 3.2 4.2 5.2 6.9 8.4 9.8 13.1 16.0 19.1 19.1
(iii) M4 1.7 2.8 3.7 4.6 6.1 7.4 8.7 11.6 14.1 16.9 16.9
(iv) M2 1.4 2.3 3.0 3.7 4.9 6.0 7.1 9.4 11.5 13.8 13.8
Figure A1.1(k). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 concrete bricks 0 5 10 15 20 25
Mean compressive strength of unit: N/mm2
5 10 15 20 30 40 50 75 100 130 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
Group 2, calcium silicate
See Table A1.1(l) and Figure A1.1(l).
Table A1.1(l). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 calcium silicate bricks
¼ 0.85 K ¼ 0.40 (i.e. wall thickness ¼ brick thickness)
Mortar Mean compressive strength of unit (N/mm2) to BS EN 771-2 (not normalised)
UK designation EN 1996-1-1 5 10 15 20 30 40 50 75 100 130 150
(i) M12 1.3 2.6 3.4 4.2 5.6 6.8 8.0 10.6 12.9 15.5 17.2
(ii) M6 1.3 2.1 2.8 3.4 4.5 5.5 6.5 8.6 10.5 12.6 14.0
(iii) M4 1.1 1.9 2.5 3.0 4.0 4.9 5.7 7.6 9.3 11.2 12.4
(iv) M2 0.9 1.5 2.0 2.4 3.3 4.0 4.7 6.2 7.6 9.1 10.0
Figure A1.1(l). Wall with a longitudinal joint: 65 mm high 102 mm thick standard format Group 2 calcium silicate bricks
0 5 10 15 20 25 30
Mean compressive strength of unit: N/mm2
5 15 30 50 100 150
Characteristic compressive strength
of masonry,
fk
: N/mm
2
fk = Kfbαfmβ
fk is the characteristic strength of masonry
K is a constant which may be taken from the National Annex fb is the normalised compressive strength of the units fm is the compressive strength of the mortar
α, β are constants which may be taken from the National Annex fb = CF × δ × mean compressive strength for bricks and blocks CF is a conditioning factor
M12 M6 M4 M2
See the section on calcium silicate units at the end of this annex.
Group 3
Wall with a longitudinal joint. Group 3 clay units have not traditionally been used in the UK, so no values are available. Group 3 calcium silicate units are not used in Europe. Group 3 concrete units have not traditionally been used in the UK, so no values are available.
Group 4
Wall with a longitudinal joint. Group 4 clay units have not traditionally been used in the UK, so no values are available. Group 4 calcium silicate units are not used in Europe. Group 4 concrete units have not traditionally been used in the UK, so no values are available.