EN 771-1
Proposal to Amend National Annex NA to EN 771-1:2003/A1
General:
Reference to EN 771-1 should be the correct reference for the amended document.
Change references to BS 4729:2004 to BS 4729:2005.
Change DD ENV 1996-1-1 to EN 1996-1-1.
NA.2 Dimensions
Change the last part of the last sentence to: "...are given in terms of their work sizes and angles in Annex B (informative) of BS 4729:2005".
NA.3.1 Dimensional deviations Add the following to the end of the last sentence: "For brickwork in thin layer mortar there are additional requirements for flatness and plane parallelism."
NA.3.3 Range Last paragraph, change " BS 4729:2004 ..." to " BS 4729:2005 Annex B ( informative)...".
NA.3.4 Configuration
Second paragraph, change the last sentence to: "EN 1996-1-1 additionally recognizes the application of other clay masonry unit groupings for which perforation volumes exceed those given in BS 3921. The revised BS 5628-1 covers the designed use of HD type clay bricks with the same limiting perforation percentages up to and including 55%, and also the use of certain clay blocks."
Delete the last sentence.
NA.3.5 Density
Change second sentence to: "Where needed, values supplied by the manufacturer are used."
NA.3.6 Compressive strength
Fourth paragraph, penultimate sentence, change "...and BS 5628 will be amended..." to "...and BS 5628 is amended…".
Last sentence, change "DD ENV 1991-1-1 is being developed ..." to " EN 1996-1-1 is developed...".
Add the following between paragraphs four and five:
"EN 771-1 requires that:
- mean compressive strength of the specified number of clay masonry units from a consignment shall not be less than the declared compressive strength;
- individual strengths of specimens measured within the test sample shall be not less than 80% of the declared value."
Change the last paragraph to: "The requirements for compressive strength are not necessarily applicable to specially shaped and accessory masonry units. When compressive strength is required suitable procedures compatible with EN 771-1 requirements are given in BS 4729:2005."
NA.3.7 Freeze/thaw resistance
Second line: delete "very".
Last sentence: Change "...that given in BS 5628-3:2001 in respect of F, M, and O bricks." To "...that given in BS 5628-3:2005."
NA.3.9 Durability designations
Table NA.5 – Practical equivalents of durability designations
Column one, row two, change "FM" to "FN".
NA.5 Clay engineering bricks
Table NA.6 – Equivalent classifying properties of traditional UK engineering and DPC bricks in relation to EN 771-1
Delete "Net dry density (kg/m3)" row.
Bibliography
All references shall be checked and if necessary revised to the latest issues.