NBS Specification Guide Colinwell Architectural Masonry block walling Tel. 028 90618 145, Fax 028 9062 4240
F10 255
(Edited version of NBS clause 255)
Colinwell Paint Quality Blocks
255B 255 CONCRETE FACING BLOCKWORK . . . . . . . . .
Blocks: To BS EN 771-3.
- Manufacturer: Colinwell Masonry
Colinwell Paint Grade Block is an economical, fire and noise resistant walling unit with a load bearing capacity. It is ideal
Product Reference: Colinwell Paint Quality Blocks
- Configuration: . . . . . . . . . . . . for use on internal leaves of a cavity construction or external cavity wall leaves when painted with a masonry paint. It is also suitable for partition walls or as a backup curtain walling on buildings from domestic to industrial, commercial and
- Compressive Strength:
Mean value: . . . . . . . . N/mm²
Characteristic value: . . . . . . . . .N/mm² even elements of prestige projects. Clause heading:
Insert, e.g. internal walls of cavity construction, for partition
Category: I
- Freeze/Thaw Resistance: as BS 5628-3:2005 Table 12
- Work Sizes (length x width x height): . . . . . . . . . . . . . . . walls, corridor walls, a back up to curtain walling - specifically where decoration is required, external leaves of
-
-
Finish/Colour: . . . . . . . . . . . . . .
Special Shapes: . . . . . . . . . . . . . cavity walls when painted with a masonry paint.
Configuration: Insert group 1, 2 or 3 as per BS EN 1996-1-
- Additional requirements: . . . . . . . . . . . .
Mortar: As section Z21.
- Standard: . . . . . . . . . . . . .
1 .
Group 1 ≤ 25% formed vertical voids by volume
Gr oup 2 > 25% ≤ 60% formed vertical voids by volume
Group 3 > 25% ≤ 70% formed vertical voids by volume
Compressive strength: 10.5
N/mm²
Freeze/Thaw Resistance: Insert, as BS 5628-3:2005 Table
12
Work size(s): Standard face size and thickness
-
-
Mix: . . . . . . . . . . . . .
Additional requirements: . . . . . . . . . . . .
 Bond: . . . . . . . . . . .

Joints: . . . . . . . . . .

Features: . . . . . . . . combinations are:

390 x 190 mm at 90, 140 and 190 mm thick.
 440 x 215 mm at 100, 140, 190 and 215 mm thick.
100mm thick block available in solid and cellular configurations. 140mm thick block available in hollow and cellular configurations. 190mm and 215mm available in hollow configuration only.
Finish The method of manufacture provides for dimensionally accurate units with sharp clean arises and low moisture absorbtion. The sizes of aggregates selected for the production of the blocks provides a texture that is particularly suitable for painting. As the blocks are a stock item consistency of colour cannot be guaranteed. Colour consistency can only be assured if the blocks are ordered to be manufactured in one production batch.
Special shapes: An extensive range of special block shapes is available. Full details, including illustrations and code references, are shown in the Colinwell Product Guide.
In addition, Colinwell offer a bespoke cutting service to produce distinctive features or solve particular design problems. Insert, e.g.
Full and half lintel blocks ref. B7,B8,L6,L5 & L4
Special cut blocks as drawing . . .
Air Leakage:
100mm cellular block (painted and unpainted) air leakage at
50 Pascals is 0.14
215mm hollow block (unpainted) air leakage at 50 Pascals is
0.80
215mm hollow block (painted) air leakage at 50 Pascals is

0.052
Certificates available http://www.colinwellconcrete.com/tech/index.asp?AreaID=P
AINT%20GRADE%20BLOCK