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BS 8204-1:2003+A1:2009

$189.07

Screeds, bases and in situ floorings – Concrete bases and cementitious levelling screeds to receive floorings. Code of practice

Published By Publication Date Number of Pages
BSI 2009 46
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This part of BS 8204 gives recommendations for constituent materials, design, work on site, inspection and testing of concrete bases that are to receive in situ wearing screeds of the following types:

  1. concrete (see BS 8204‑2);

  2. polymer modified cement (see BS 8204‑3);

  3. terrazzo (see BS 8204‑4);

  4. mastic asphalt (see BS 8204‑5);

  5. synthetic resin (see BS 8204‑6);

  6. magnesium oxychloride;

  7. pumpable self-smoothing screeds (see BS 8204‑7);

and for bases and levelling screeds that are to receive flexible floor coverings such as:

  1. textiles;

  2. linoleum;

  3. polyvinyl chloride;

  4. rubber;

  5. cork;

and rigid floorings such as:

  1. wood block and strip;

  2. laminate floor coverings;

  3. ceramic tiles;

  4. natural stone.

It applies to ground-supported and suspended concrete floor bases.

This part of BS 8204 includes the use of concrete and levelling screeds made with lightweight aggregates conforming to BS EN 13055‑1. Where the recommendations differ from those for normal weight aggregates, these are given in Annex A.

Recommended methods for the assessment of levels and surface regularity and for the determination of in situ crushing resistance (soundness) are given in Annex C, Annex D and Annex E.

This part of BS 8204 is not intended to provide guidance on the structural design or related construction of concrete ground-supported floors or suspended slabs. Information on these aspects is given in BS 8110‑1 and reference [4]. The specification of concrete for base slabs is given in BS 8500‑2. The recommendations in this code of practice relate to those other aspects of design and construction of concrete slabs that affect the performance of the overlying levelling or wearing screed.

NOTE BS 8110‑1 is obsolescent and will be superseded by BS EN 1992‑1‑1:2004 in March 2010.

See Part 3 for polymer modified cementitious levelling screeds.

PDF Catalog

PDF Pages PDF Title
1 BRITISH STANDARD
2 Committees responsible for this British�Standard
3 Contents
5 1 Scope
2 Normative references
6 3 Terms and definitions
3.1 base
3.2 flooring
3.3 direct finished base slab
3.4 screed material
7 3.5 screed
3.6 levelling screed
3.7 wearing screed
3.8 bonded screed
3.9 unbonded screed
3.10 floating screed
3.11 fine concrete screed
3.12 cement sand screed
3.13 smoothing compound
3.14 departure from datum
3.15 surface regularity
3.16 in situ crushing resistance (ISCR)
8 3.17 no-fines concrete basecoat
3.18 cement sand topping
3.19 combinations
9 Figure 1 Illustration of layers in a ground-supported concrete floor
10 Figure 2 Illustration of layers in a suspended concrete floor
11 4 Exchange of information and time schedule
4.1 General
4.2 Exchange of information
12 4.3 Time schedule
5 Materials
5.1 Cement
14 5.2 Additions
5.3 Aggregates
5.4 Admixtures
Table 1 British Standards for admixtures
15 5.5 Ready-mixed concrete for bases
5.6 Ready-mixed levelling screeds
5.7 Reinforcement
5.8 Water
6 Design considerations
6.1 Sub-base
6.2 Base and screed construction
16 6.3 Base slabs
Table 2 Concrete strength for base slabs
6.4 Cement sand and fine concrete levelling screeds
18 Table 3 Choice of in�situ crushing resistance category for levelling screeds
19 Table 4 Acceptance limits for in�situ crushing resistance test (after�dropping�the�weight�four�times)
21 6.5 Bay sizes and position of joints
Table 5 Classification of surface regularity of direct finished base slab or levelling screed
22 6.6 Joint construction
6.7 In�situ crushing resistance (soundness)
23 6.8 Tolerances on level and surface regularity of base slabs and levelling screeds
24 6.9 Liability to cracking of direct finished base slabs and levelling screeds
25 6.10 Damp-proofing ground-supported floors
26 6.11 Eliminating construction moisture
27 7 Work on site
7.1 Protection against the weather
28 7.2 Use of calcium aluminate cement (high alumina cement)
7.3 Installation of the base
29 7.4 Preparation of the base to receive screeds
30 7.5 Installation of the screed
31 7.6 Pumping the screed material
7.7 Using ready-to-use screed material
7.8 Laying the levelling screed
32 7.9 Finishing the levelling screed
7.10 Curing the levelling screed
7.11 Protection of the surface
33 8 Inspection and testing of bases and levelling screeds
8.1 Inspection
8.2 Inspection and testing of the completed work
8.3 Levels and surface regularity
8.4 Adhesion of bonded levelling screeds to the base
34 8.5 Curling and lipping of unbonded and floating levelling screeds
8.6 In�situ crushing resistance (ISCR) of bonded and unbonded levelling screeds
8.7 In�situ crushing resistance of floating levelling screeds
8.8 Assessment of cracks
8.9 Determination of constituent material proportions of a failed or suspect levelling screed
35 Annex A (normative) Recommendations for the use of lightweight aggregates in concrete bases and levelling…
A.1 Aggregates
A.2 Base and levelling screed construction
A.3 Direct finished base slabs
A.4 Bonding
A.5 Thickness
A.6 Location of services
36 A.7 Heated levelling screeds
A.8 Bay sizes
A.9 In situ crushing resistance
A.10 Screed proportions, batching and mixing
A.11 Method of mixing
A.12 Pumping the screed material
A.13 Laying the levelling screed
37 Annex B (informative) Guidance for specifying sands for cement sand levelling screeds: comparison of the …
38 Table B.1 Sand descriptions and recommended European designations
Table B.2 Comparison of the grading and fines content limits of aggregates in BS�EN�13139 with established …
39 Annex C (normative) Methods for the assessment of levels and surface regularity
C.1 The following methods should be used to assess deviations of levels and surface regularity.
C.2 Where the straight-edge basis for specification is used it is advisable for the various intereste…
C.3 Check deviation of levels from datum using standard surveying methods.
C.4 Check surface regularity by using a straightedge 2 m long laid in contact with the floor surface …
Figure C.1 Stainless steel slip gauges for checking surface regularity
40 Annex D (normative) Method for the determination of in�situ crushing resistance of bonded and unbonded le…
D.1 Principle
D.2 Apparatus
D.3 Sampling
D.4 Procedure
D.5 Expression of results
41 Figure D.1 BRE screed tester
42 Annex E (normative) Determination of in�situ crushing resistance of floating levelling screeds
E.1 Principle
E.2 Apparatus
E.3 Sampling
E.4 Procedure
43 E.5 Results
Annex F (normative) Curing recommendations for different cement types
BS 8204-1:2003+A1:2009
$189.07