ICS 91.100.25  
 
Reference number  
DRS 511 : 2022  
© RSB 2022  
  
 RWANDA 
STANDARD  DRS 
511  
 
First e dition  
2022 -mm-dd 
 
Clay flooring tiles — Specification  
   
DRS 511 : 2022  
©RSB 2022 - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition 
 
 
 
 
 
 
 
 
© RSB 2022  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce this document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw   DRS 511 : 2022  
iii                ©RSB 2022  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 Classification  ................................ ................................ ................................ ................................  1 
5 Requirements  ................................ ................................ ................................ ................................  2 
5.1 Raw materials  ................................ ................................ ................................ ...............................  2 
5.2 Manufacturing  ................................ ................................ ................................ ...............................  2 
5.3 Workmanship  ................................ ................................ ................................ ................................  2 
5.4 Performance requirements  ................................ ................................ ................................ ..........  2 
6 Tolerances on dimensions and warpage  ................................ ................................ ...................  3 
6.1 Dimensions  ................................ ................................ ................................ ................................ ... 3 
6.2 Warpage  ................................ ................................ ................................ ................................ ........  3 
7 Sampling  ................................ ................................ ................................ ................................ ....... 3 
8 Marking  ................................ ................................ ................................ ................................ ..........  4 
Annex  A (informative)   Nominal dimensions of flooring tiles  ................................ ...............................  5 
Annex  B (normative)  Determination of flexural strength  ................................ ................................ ..... 6 
B.1 Test specimens  ................................ ................................ ................................ .............................  6 
B.2 Apparatus  ................................ ................................ ................................ ................................ ...... 6 
B.3 Procedure  ................................ ................................ ................................ ................................ ...... 7 
B.4 Calculation and report test results  ................................ ................................ .............................  8 
 DRS 511 : 2022  
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 Foreword  
Rwanda Standard s are prepared  by Technical Committees and approved by Rwanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards adopted 
by Technical committ ees are ratifie d by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS 511  was prepared by Technical Committee RSB/TC 9, Civil engineering and building materials . 
In the preparation of this standard, reference was made to the following standard:  
1) IS 1478: 1992 (Reaffirmed 2021) , Clay flooring tiles — Specification    
2) Philippine s National Standard (PNS) 154:2005 , Ceramic wall and floor tiles – Specification  
The assistance de rived from the above source is hereby acknowledged with thanks.  
Committee membership  
The following organizations were represented on the Technical Committee on Civil engineering and building 
materials  (RSB/TC 9) in the preparation of this standard.  
A+Construction Group Ltd  
Africeramics Ltd  
Consultants Engineers Group (CEG) Ltd  
D&D Resources Ltd  
Dutureheza Ltd  
Enabel Rwanda  
Greenpack Africa Ltd  
Integrated Polytechnic Regional Centre (IPRC) - Musanze  
Mass Design Group  
NP Construction Construction Company (NPCC) Ltd  
Road Trans port Development Agency (RTDA)  DRS 511 : 2022  
v                ©RSB 2022  - All rights reserved  
 Rwanda Housing Authority (RHA)  
Rwanda Inspectorate, Competition and Consumer Protection Authority (RICA)  
Rwanda Quarries Association (RQA)  
SKAT Consult  
St Joseph Engineering Company (SJEC) Ltd  
Standards for Sustainability (S fS) 
Stonecraft Industries Ltd  
University of Rwanda - College of Science and Technology (UR - CST)  
Rwanda  Standards Board  (RSB) – Secretariat  
 DRS 511 : 2022  
1                ©RSB 2022  - All rights reserved  
 Clay flooring tiles — Specification  
1 Scope  
This Draft Rwanda Standard specifies requirements , sampling and test methods  for flooring  tiles. 
2 Normative reference s 
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amend ments) applies.  
DRS 546 , Clay products for building — Vocabulary  
RS ISO 10545 -2, Ceramic tiles — Part 2: Determination of dimensions and surface quality  
RS ISO 10545 -3, Ceramic tiles — Part 3: Determination of water absorption, apparent porosity, apparent 
relative density and bulk density  
RS ISO 10545 -4, Ceramic tiles — Part 4: Determination of modulus of rupture and breaking strength  
RS ISO 10545 -5, Ceramic tiles — Part 5: Determination of impact resistance by measurement of coefficient 
of restitu tion 
RS ISO 10545 -7, Ceramic tiles — Part 7: Determination of resistance to surface abrasion for glazed tiles  
RS ISO 10545 -16, Ceramic tiles — Part 16: Determination of small colour differences  
RS 107, Building sand from natural sources — Specification  
3 Terms and definitions  
For the purpose of this standard, the  terms and definitions given in  DRS 546  and the following  apply.  
4 Classification   
The clay flooring tiles shall be of the three classes namely Class 1, Class 2 and Class  3.  
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 5 Requirements  
5.1 Raw materials  
The clay flooring tiles shall be made from good  raw materials  of even texture and shall be uniformly well  burnt. 
When sand is used, it shall meet requirements of RS 107.  
NOTE  Raw materials include clay, feldspar, sand/silica, ka oline and carbonates . 
5.2 Manufacturing  
The tiles shall be manufactured in a system that ensures consistency in quality. The system shall put in place 
measures to ensure the quality of raw materials, production and post -production management. The system shall  
be documented.  
5.3 Workmanship  
5.3.1 Clay flooring tiles  shall be uniform in size and shape  and shall be free from unslaked lime particles 
irregularities, such as  twists, bends, cracks, flaws, laminations and  imperfections which affect appearance or 
serviceability.   
5.3.2 The faces of tiles shall be plain, grooved,  fluted or figured as specified and the edges shall  be square.  
5.3.3 The backs of the tile may have  some type of either plain or engraved or  embossed design . The flooring 
tiles shall be wea ther-proof and corrosion -resistant and have adequate mechanical strength for covering floors.   
5.3.4 The depth of the grooves or frogging on the underside of flooring tiles shall not exceed 3 mm.  
5.4 Performance requirements  
The clay flooring tiles shall comply with the  performance requirements given in Table 1  when tested in 
accordance with the test methods specified therein.   
  
 
 
 
 
 
 DRS 511 : 2022  
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 Table 1  — Performance requirements for different classes of flooring tiles  
 
S/No.N  Characteristic  Requirements for  Test methods  
Class 1  Class 2  Class 3  
i) Water absorption percent, max  10 19 24 RS ISO 10545 -3 
ii) Flexural strength, kg/cm width, Min:  Annex B  
  a) Average  6 3.5 2.5 
  b) Individual  5 3 2 
iii) Impact, maximum height in mm of drop of steel ball  RS ISO 10545 -5 
  a) 15 mm thick  25 20 15 
  b) 20 mm  60 50 40 
  c) 25mm  75 65 50 
  d) 30 mm  80 70 60 
 Abrasion resistance (loss in 
volume), mm3, max.  175 175 175 RS ISO 10545 -7 
 Chemical resistance  Resistant  resistant  Resistant  RS ISO 10545 -16 
 Modulus of rupture , MPa  4.0 3.0 2.5 RS ISO 10545 -4 
6 Tolerances on d imensions and warpage  
6.1 Dimensions  
When measured in accordance with  RS ISO 10545 -2, the dimensions for clay flooring tiles shall be as declared 
by the manufacturer or as agreed between to  the purchaser and the manufacturer, subject to the tolerance of ±  
5 mm for length and width and ± 2 mm for thickness.  
NOTE  Nominal dimensions of the tile s   are given in Annex  A. 
6.2 Warpage  
6.2.1  When measured in accordance with 6.2.2 , the warpage  shall not exceed 0.7 % along the edges and 
0.5 % along the diagonals.  
6.2.2 Place a straight edge flat over the tile resting on a plane surface so as to leave maximum gap between 
the straight edge and the surface of the tile, as judged by the naked eye.  Insert the measuring metallic wedge 
(see Fig. 1) in the gap and measure the m aximum value of the gap.  
7 Sampling  
Sampling shall be performed in accordance with RS ISO 10545 -1.  
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 8 Marking  
8.1 Each tile shall be legibly and indelibly  marked with the registered name or trademark of the manufacturer . 
8.2 In addition to t he information  in 8.1, and the following shall be legibly and indelibly marked on the bulk 
packaging:  
a) the manufacturer, usage and class ; 
b) nominal dimensions ; 
c) address of the manufacturer ; 
d) country of manufacture ; and  
e) reference to this Standard . DRS 511 : 2022  
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 Annex  A 
(informative)  
 
Nominal dimensions of flooring tiles  
The nominal dimensions for clay flooring tiles are given in Table A.1  and A.2. The tiles in Table A.1 are for areas 
where no vehicles are permitted such as sidewalks, etc. Tiles in Table A.2 can be used in  areas where vehicles 
are permitted.  
Table A.1 — Nominal dimensions of floor tiles  for sidewalks and other light applications  
 
Table A.2 — Dimensions for sides and thickness of tiles for  areas where vehicles are permitted  
 
 
 
 
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 Annex  B 
(normative)  
 
Determination of flexural strength  
B.1 Test specimens  
Six tiles shall be used for this test from  the sample selected in the manner described  in 7. 
B.2 Apparatus  
B.2.1 The apparatus ( see Fig. 2 ) shall consist  of two parallel self -aligning cylindrical steel  bearers, with the 
bearing surface rounded to  40 mm diameter, and so placed that the distance  between the centres can be 
altered. The load  shall be applied through a third steel bearer of  similar shape placed midway between and  
parallel to the supports. The  length of all the  bearers shall exceed the maximum width of the  tile under test for 
square and rectangular tiles.  
B.2.1 The loading device may consist of a  bucket connected either directly or through  levers to the loading 
arms. The loading shall be  at a u niform rate of 450 to 550 N /min by allowing  lead shots to flow into the bucket. 
Provision  shall be  made to arrest the flow or lead shots  immediately as the tile breaks . DRS 511 : 2022  
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B.2.2 Alternatively, a compression testing  machine with a minimum load frame capacity  of 10 tons may be 
used ( see Fig. 3 ), In this  system the bearer assembly is mounted on a  rigid mild steel plate and the third central 
loading  bearing is  fixed through a suitable dial  micrometre ( least count 0’25 mm ) or an equally  sensitive devi ce 
to bear on the loading  member  or on the specimen at mid span. The specimen  is supported on the bottom 
parallel bearers  separated by a distance of minimum three -fourths  ( 3/4 ) of the length of the tile.  
B.2.2.1  The error in the load reading shall not  exceed 2’2 N for loads up to 220 N and for  greater load, the 
error shall not  exceed 1 percent  of the maximum load. The rate of loadings  should be uniform and vary in the 
range  of 450 -550 N/min.  
B.3 Procedure  
B.3.1 Test three tiles in the dry condition, that  is, after drying in an oven at 10  0°C to 1l0 °C till constant weight 
is attained and the other three  tiles after soaking in water at 24  °C to 30 °C for  24 h. Support the tile evenly 
flatwise on  the bearers  set with a span equal to three -fourths  the dimension s of the tile and resting on  tile natural 
bottom surface. To ensure uniform  distribution of load at supports, provide suitable  packing between the tile and 
 
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 the bearers. Apply  the load with the direction of the load  perpendicular  to the span at a u niform rate of 450  to 
550 N/min  
B.4 Calculation and report test results  
B.4.1  The individual breaking load shall be  recorded and the flexural strength shall be obtained  width by 
dividing the breaking load by the width  of the tile  and the average of the six val ues calculated.  
B.4.2 The result shall be expressed in N/mm  width.  
 
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B.4.3 Steel rule, graduated in increments of 1 mm.  
B.4.4 Steel straight -edge, of length at least 450 mm.  
B.4.5 Four steel measuring wedges, graduated in increments (indicating increments of thickness) of 1 mm, 
and each of length 60 mm, of width 10 mm and of a thickness that tapers uniformly from 10 mm at one end to 
zero at the other end.  
C.1.4 Flat surface of steel or glass, of size at least 450 mm × 450 mm, and plane to within 0.15 mm.  
 
 DRS 511 : 2022  
 
Price based on  9 pages  
©RSB 2022 - All right s reserved   
 Bibliography  
 
[1] RS 310: 20 22, Burnt clay paving units — Specification