BS ISO 13638:2021 pdf download – Building and civil engineering sealants — Determination of resistance to prolonged exposure to water
For the purposes of this document, the terms and definitions given in ISO 6927 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at
— IEC Electropedia: available at
4 Principle
Test specimens are prepared in which the sealant to be tested adheres to two parallel contact surfaces. After immersion of the test specimens in water under defined conditions, they are subjected to repeated extension and compression movements in a suitable device, at an amplitude which is 50 % of that used in the test to assess the respective movement accommodation factor. This procedure is repeated a number of times, or until failure of one or more test specimens is observed. The number of repetitions of water immersion followed by extension/compression movement is related to the expected water resistance in service.
Water immersion may be carried out either at ambient temperature (23 °C), or at elevated temperature (40 °C or 50 °C) to accelerate the influence of the exposure to water.
c) trim the sealant surface so that it is flush with the faces of the substrates and spacers.
Set the test specimens on the edge of one of the substrates and remove the anti-adherent substrate as soon as possible. Let the specimens rest in this position to allow curing or optimum drying of the sealant. Maintain the spacers in place during conditioning.
7 Conditioning
7.1 General
Condition the test specimens in accordance with either method A or method B, as agreed between the parties concerned.
7.2 Method A
Condition the test specimens for 28 days at (23 ± 2) °C and (50 ± 10) % relative humidity.
7.3 Method B
Condition the test specimens according to method A and then subject them three times to the following storage cycle:
a) 3 days in the oven (5.4) set at 70 °C;
b) 1 day in the container (5.5) filled with distilled water maintained at 23 °C;
c) 2 days in the oven (5.4) set at 70 °C;
d) 1 day in the container (5.5) filled with distilled water maintained at 23 °C.
Alternatively, this cycle may be performed in the order c), d), a) then b).
NOTE Method B is a commonly used conditioning procedure using the influence of heat and water. It is not suitable for giving information on the durability of the sealant.
8 Procedure
8.1 Water immersion
After conditioning, remove the spacers and store the test specimens for 3 weeks in the container (5.6) filled with distilled water maintained at 23 °C, 40 °C or 50 °C. At the end of the period of immersion, remove the test specimens from the water and store them for 1 h at (23 ± 2) °C and (50 ± 10) % relative humidity.
8.2 Cyclic movement
The movement accommodation factor for the sealant shall be determined by the method of ISO 9046 or ISO 9047, as appropriate by reference to ISO 11600.
The amplitude of the extension/compression cycle in the test machine (5.6) shall be 50 % of the movement capability classification according to ISO 11600. The speed of extension and compression used in the cyclic test procedure shall be (5,5 ± 0,5) mm/min and the amplitude ±6,25 %, ±10 % or ±12,5 % of the nominal width, or as required. The procedure shall be carried out at (23 ± 2) °C and (50 ± 10) % relative humidity. First extend the test specimens by the requisite amount and maintain this extension for 24 h.
Then release the extension and compress the test specimens to the requisite amount. Maintain this compression for 24 h. Repeat this extension/compression procedure twice. At the conclusion of the third cycle, release the compression and allow the specimens to recover for 1 h in air at (23 ± 2) °C. 8.3 Visual inspection Carefully examine the test specimens for any loss of cohesion or adhesion.
Measure the depth of any adhesive or cohesive failures using a suitable measuring device (5.10) capable of reading to 0,5 mm. Because of the excessive stress experienced by the sealant near the ends of the test specimens, during both the preparation and testing, loss of adhesion or cohesion observed within the excluded volume 2 mm × 12 mm × 12 mm, at either or both ends of the sealant, shall not be reported as a failure (see Figure 3).