Dense
concrete blocks
7.3N/mm217.5N/mm2 to BS EN 771-3
7.3N/mm2 (OVEN-DRY DENSITY approx 1900 kg/m3)
Size
mm
nominal
approx
weight kg
no. per
tonne
multiples
of
no. per
pack
440x215x75
14.0
72
56
112
440x215x90
16.5
60
48
96
440x215x100†
18.5
54
44
88
440x215x140†
26•
38
32
64
440x215x190†
35•
28
20
40
10.4N/mm2 (OVEN-DRY DENSITY approx 1950 kg/m3)
Size
mm
nominal
approx
weight kg
no. per
tonne
multiples
of
no. per
pack
440x215x100†
20
50
44
88
440x215x140†
28•
36
32
64
440x215x190†
38•
26
20
40
Coursing
bricks
65x215x100
2.9
340
128
512
65x215x140
4.2
240
96
384
17.5N/mm2 (OVEN-DRY DENSITY approx 2000 kg/m3)
Size
mm
nominal
approx
weight kg
no. per
tonne
multiples
of
no. per
pack
440x215x100
21•
48
44
88
440x215x140
29•
34
32
64
• Blocks in excess of 20kg – please use with caution after assessing the risks.
† Also available in close texture.
U-Value 0.23
Outside
resistance
0.040
19mm sand/cement render (λ 1.00)
0.019
100mm dense 7.3N/mm2 (λ 1.31)
0.076
50mm low emissivity cavity
0.640
50mm foil-faced partial fill PIR/PU board (λ 0.022)
2.273
100mm dense 7.3N/mm2 (λ 1.22)
0.082
15mm dabs
0.170
25mm phenolic insulation (λ 0.022)
1.136
bonded to...
13mm plasterboard
(λ 0.21)
0.062
Inside resistance
0.130
Sum of resistances
4.628 m2K/W
Uncorrected U-value
0.216 W/m2K
Mortar correction
0.000
Air gap correction
0.010
Wall tie correction - Staifix HRT4-225
0.001
U-VALUE
0.227W/m2K
U-Value 0.24
Outside
resistance
0.040
19mm sand/cement render (λ 1.00)
0.019
100mm dense 7.3N/mm2 (λ 1.31)
0.076
125mm high performance mineral wool (λ 0.032)
3.906
100mm dense 7.3N/mm2 (λ 1.22)
0.082
13mm dense plaster (λ 0.57)
0.023
Inside resistance
0.130
Sum of resistances
4.276m2K/W
Uncorrected U-value
0.234 W/m2K
Mortar correction
0.000
Air gap correction
0.000
Wall tie correction - Staifix HRT4-250
0.002
U-VALUE
0.236W/m2K
U-Value 0.25
Outside
resistance
0.040
19mm sand/cement render (λ 1.00)
0.019
100mm dense 7.3N/mm2 (λ 1.31)
0.076
50mm low emissivity cavity
0.640
70mm foil-faced partial fill PIR/PU board (λ 0.022)
3.182
100mm dense 7.3N/mm2 (λ 1.22)
0.082
13mm dense plaster (λ 0.57)
0.023
Inside resistance
0.130
Sum of resistances
4.192m2K/W
Uncorrected U-value
0.239 W/m2K
Mortar correction
0.000
Air gap correction
0.010
Wall tie correction - Staifix HRT4-250
0.002
U-VALUE
0.251W/m2K
Stowell dense concrete blocks offer the builder a full range of solid concrete blocks with a well-established durability, low drying shrinkage and proven acoustic properties that will fulfil most applications. They are manufactured to BS EN 771-3 using Class 1 limestone aggregates.
The blocks are available in a standard face size of 440x215mm and in thicknesses of 75mm, 90mm, 100mm, 140mm and 190mm in a standard finish (suitable for rendering).
100mm, 140mm and 190mm wide blocks are available in close texture finish, please CLICK HERE for more information..
43dB(A) 75mm single skin, 175kg/m2
44dB(A) 90mm single skin, 205kg/m2
45dB(A) 100mm single skin, 225kg/m2
47dB(A) 140mm single skin, 300kg/m2
48dB(A) 190mm single skin, 395kg/m2
17.5N/mm2 
