Work Item
ASTM WK83661

New Test Method for Grout Retention Properties of Ceramic Tile

1. Scope

1. Scope

1.1 This test method covers the testing and evaluation of grout retention on glazed and unglazed ceramic tile surfaces and is intended to give the user a uniform procedure to make a comparative assessment of specific tile and grout systems.
1.2 The values stated in inch-pound units are to be regarded as the standard. The values in parentheses are for information only.
1.3 This qualitative method is intended to be used to visually detect abnormal grout retention for a specific
tile and installation material system installed in a specified way.
1.4 This method is intended to evaluate the specific grout and tile system specified and is not intended for
test results to encompass other tile and grout combinations
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is
the responsibility of the user of this standard to establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to use.


Grout; clean up; staining; retention; haze


Grout retention or grout staining is a specific concern to end users. An installation that experiences grout staining is often expensive to fix. Currently ASTM does not have an adequate test method to evaluate this issue. We have found that the ASTM Stain Resistance Test (C1378) does not always identify surfaces that will be susceptible to grout staining.

Causes of unacceptable grout retention can include (but are not limited to): tile manufacturing issues, grout manufacturing issues, and/or installation issues.

It is acceptable for specific products to retain a small amount of grout. Therefore not all
grout retention is detrimental. It is necessary to evaluate each system on a case by case basis.

Some types of tiles require the use of a grout release (or sealer) per manufacturer's instructions. Installation instructions shall be taken into account when evaluating various systems.

Grout retention characteristics are a function of the materials being used and installation practices. The industry needs a method to differentiate this criteria and troubleshoot issues.

This method is intended for:
•? Use by installers to determine if the tile and installation materials are synergetic
•? Use by tile and gout manufacturers to evaluate production
•? As a tool for forensic flooring specialists to determine if the tile/grout system was

The title and scope are in draft form and are under development within this ASTM Committee.


Developed by Subcommittee: C21.06

Committee: C21

Staff Manager: Melissa Marcinowski

Work Item Status

Date Initiated: 10-04-2022

Technical Contact: James Neel

Item: 001

Ballot: C21.06 (22-01)

Status: In Balloting